WorldWideScience

Sample records for sunset sky show

  1. Color Variations in the Sky at Sunset

    Science.gov (United States)

    1997-01-01

    This image of the martian sunset from Sol 24 shows much more color variation than had previously been seen. The blue color near the Sun is not caused by clouds of water ice, but by the martian dust itself. The dust in the atmosphere absorbs blue light, giving the sky its red color, but it also scatters some of the blue light into the area just around the Sun because of its size. The blue color only becomes apparent near sunrise and sunset, when the light has to pass through the largest amount of dust. This image was taken by the Imager for Mars Pathfinder.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  2. Blue moons and Martian sunsets.

    Science.gov (United States)

    Ehlers, Kurt; Chakrabarty, Rajan; Moosmüller, Hans

    2014-03-20

    The familiar yellow or orange disks of the moon and sun, especially when they are low in the sky, and brilliant red sunsets are a result of the selective extinction (scattering plus absorption) of blue light by atmospheric gas molecules and small aerosols, a phenomenon explainable using the Rayleigh scattering approximation. On rare occasions, dust or smoke aerosols can cause the extinction of red light to exceed that for blue, resulting in the disks of the sun and moon to appear as blue. Unlike Earth, the atmosphere of Mars is dominated by micron-size dust aerosols, and the sky during sunset takes on a bluish glow. Here we investigate the role of dust aerosols in the blue Martian sunsets and the occasional blue moons and suns on Earth. We use the Mie theory and the Debye series to calculate the wavelength-dependent optical properties of dust aerosols most commonly found on Mars. Our findings show that while wavelength selective extinction can cause the sun's disk to appear blue, the color of the glow surrounding the sun as observed from Mars is due to the dominance of near-forward scattering of blue light by dust particles and cannot be explained by a simple, Rayleigh-like selective extinction explanation.

  3. Alien Sunset (Artist Concept)

    Science.gov (United States)

    2007-01-01

    Our solitary sunsets here on Earth might not be all that common in the grand scheme of things. New observations from NASA's Spitzer Space Telescope have revealed that mature planetary systems -- dusty disks of asteroids, comets and possibly planets -- are more frequent around close-knit twin, or binary, stars than single stars like our sun. That means sunsets like the one portrayed in this artist's photo concept, and more famously in the movie 'Star Wars,' might be quite commonplace in the universe. Binary and multiple-star systems are about twice as abundant as single-star systems in our galaxy, and, in theory, other galaxies. In a typical binary system, two stars of roughly similar masses twirl around each other like pair-figure skaters. In some systems, the two stars are very far apart and barely interact with each other. In other cases, the stellar twins are intricately linked, whipping around each other quickly due to the force of gravity. Astronomers have discovered dozens of planets that orbit around a single member of a very wide stellar duo. Sunsets from these worlds would look like our own, and the second sun would just look like a bright star in the night sky. But do planets exist in the tighter systems, where two suns would dip below a planet's horizon one by one? Unveiling planets in these systems is tricky, so astronomers used Spitzer to look for disks of swirling planetary debris instead. These disks are made of asteroids, comets and possibly planets. The rocky material in them bangs together and kicks up dust that Spitzer's infrared eyes can see. Our own solar system is swaddled in a similar type of disk. Surprisingly, Spitzer found more debris disks around the tightest binaries it studied (about 20 stars) than in a comparable sample of single stars. About 60 percent of the tight binaries had disks, while the single stars only had about 20 percent. These snug binary systems are as close or closer than just three times the distance between Earth and

  4. Colors of the Sky.

    Science.gov (United States)

    Bohren, Craig F.; Fraser, Alistair B.

    1985-01-01

    Explains the physical principles which result in various colors of the sky. Topics addressed include: blueness, mystical properties of water vapor, ozone, fluctuation theory of scattering, variation of purity and brightness, and red sunsets and sunrises. (DH)

  5. Red rainbows at sunset/sunrise

    Science.gov (United States)

    Ricard, J. L.

    2016-12-01

    The rainbow model deveeloped at CEPAL is based on the Airy theory. The outputs show that a pure red rainbow could only observed from a hill or a mountain when the sun is below the horizon. When the sun is on the horizon, there should be a juxtaposition of a red band on the outside and of a yellow band on the inside (upper figures). However, observers report pure red bows at sea level (lower left figure). In these rare cases, it is possible to still see the sun after it has set. As sunlight passes through more and more dense atmosphere at sunset the light slows and bends closer and closer toward the normal. When the eye traces the light ray it appears to be higher in the sky (lower right figure).

  6. Blue Skies, Coffee Creamer, and Rayleigh Scattering

    Science.gov (United States)

    Liebl, Michael

    2010-01-01

    The first physical explanation of Earths blue sky was fashioned in 1871 by Lord Rayleigh. Many discussions of Rayleigh scattering and approaches to studying it both in and out of the classroom are available. Rayleigh scattering accounts for the blue color of the sky and the orange/red color of the Sun near sunset and sunrise, and a number of…

  7. Blue Skies, Coffee Creamer, and Rayleigh Scattering

    Science.gov (United States)

    Liebl, Michael

    2010-01-01

    The first physical explanation of Earths blue sky was fashioned in 1871 by Lord Rayleigh. Many discussions of Rayleigh scattering and approaches to studying it both in and out of the classroom are available. Rayleigh scattering accounts for the blue color of the sky and the orange/red color of the Sun near sunset and sunrise, and a number of…

  8. Spectacular Skies

    Science.gov (United States)

    Nickerson, Jessica

    2008-01-01

    Marbling paper is a favorite in many elementary classrooms. The marbling project described in this article, using a sunset and silhouette concept, is foolproof, inexpensive, and engaging. After looking at images of incredible sunsets for inspiration, each student uses marbling paper, black construction paper, three colors of chalk, and a tub of…

  9. 14 CFR 255.8 - Sunset Date.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Sunset Date. 255.8 Section 255.8 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS AIRLINE COMPUTER RESERVATIONS SYSTEMS § 255.8 Sunset Date. Unless extended by a document published...

  10. 42 CFR 403.756 - Sunset provision.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Sunset provision. 403.756 Section 403.756 Public... PROVISIONS SPECIAL PROGRAMS AND PROJECTS Religious Nonmedical Health Care Institutions-Benefits, Conditions of Participation, and Payment § 403.756 Sunset provision. (a) Effective date. Beginning with FFY...

  11. Identification of tartrazine and sunset yellow by fluorescence spectroscopy combined with radial basis function neural network

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Guoqing Chen; Tuo Zhu; Shumei Gao; Bailin Wei; Linna Bi

    2009-01-01

    @@ The fluorescence spectra of synthetic food dyes of sunset yellow and tartrazine are analyzed.The fluorescence peak wavelengths of sunset yellow and tartrazine are 576 and 569 nm, respectively, while the fluorescence spectra widths are 480-750 and 500-750 nm induced by ultraviolet light between 310-400 nm.The fluorescence spectra of sunset yellow overlap heavily with those of tartrazine, so it is diffic ult to distinguish them.Based on the principle of radial basis function neural network, a neural network is obtained from the training of the 14 groups of experimental data.The results show that the species of sunset yellow and tartrazine could be recognized accurately.This method has potential applications in other synthetic food dyes detection and food safety inspection.

  12. The Rainbow Sky

    CERN Document Server

    Buick, Tony

    2010-01-01

    The world is full of color, from the blue ocean and the yellow daffodils and sunflowers in green carpeted meadows to the majestic purple mountains in the distance and brightly hued coral reefs off the edges of tropical coasts. But what is color, exactly? Why do we see things in different colors? Do we all see the same colors? Like the surface of our planet, the sky above us offers us an endless palette of color, a visual feast for the eyes. Besides atmospheric phenomena such as sunsets and rainbows, there are the many varied worlds of the Solar System, which we can spy through our telescopes, with their subtle colorings of beige and blue and green. Faraway star systems have suns that come in shades ranging from red and yellow to blue and white. Scientists even often use "false colors" to enhance the features of images they take of structures, such as the rings of Saturn and Jupiter’s clouds. This book, with its clear explanations of what makes the sky such a colorful place and in its great wealth of picture...

  13. Local mirror symmetry and the sunset Feynman integral

    CERN Document Server

    Bloch, Spencer; Vanhove, Pierre

    2016-01-01

    We study the sunset Feynman integral defined as the scalar two-point self-energy at two-loop order in a two dimensional space-time. We firstly compute the Feynman integral, for arbitrary internal masses, in terms of the regulator of a class in the motivic cohomology of a 1-parameter family of open elliptic curves. Using an Hodge theoretic (B-model) approach, we show that the integral is given by a sum of elliptic dilogarithms evaluated at the divisors determined by the punctures. Secondly we associate to the sunset elliptic curve a local non-compact Calabi-Yau 3-fold, obtained as a limit of elliptically fibered compact Calabi-Yau 3-folds. By considering the limiting mixed Hodge structure of the Batyrev dual A-model, we arrive at an expression for the sunset Feynman integral in terms of the local Gromov-Witten prepotential of the del Pezzo surface of degree 6. This expression is obtained by proving a strong form of local mirror symmetry which identifies this prepotential with the second regulator period of the...

  14. SKY WATCHER

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China’s largest optical telescope will soon come online to benefit the country and the world The limits of human sight have been expanding ever since Galileo pointed his telescope to the sky 400 years ago. And now, LAMOST, the Chinese-built Large Sky Area Multi-Object Fiber

  15. The last sunset on mainland Europe

    CERN Document Server

    Mira, Jorge

    2014-01-01

    This paper documents the places in mainland Europe at which the sun sets latest, by Coordinated Universal Time (UTC), on any given day (distortion due to differences in local standard times is ignored). In contradiction to the na\\"ive assumption that the sun always sets latest at the westernmost point, the point of last sunset changes cyclically over the course of a year due to the changing orientation of the axis of the Earth with respect to the sun. Specifically, between the winter and summer solstices the last sunset shifts successively from Cabo de Sao Vicente (Portugal) to Cabo da Roca (Portugal) to Cabo Tourinan (Spain) to a site near Aglapsvik (Norway) to a location in the Norwegian municipality of Masoy south of Havoysund; and it shifts back again between the summer and winter solstices. There are two days in the year (April 24th and August 18th) on which the last sunset of mainland Europe (shared in those days effectively by Cabo Tourinan and the Aglapsvik area) coincides with the last sunset of main...

  16. Headspace Solid-Phase Microextraction Analysis of Volatile Components in Phalaenopsis Nobby’s Pacific Sunset

    Directory of Open Access Journals (Sweden)

    Chih-Hsin Yeh

    2014-09-01

    Full Text Available Phalaenopsis is the most important economic crop in the Orchidaceae family. There are currently numerous beautiful and colorful Phalaenopsis flowers, but only a few species of Phalaenopsis have an aroma. This study reports the analysis volatile components present in P. Nobby’s Pacific Sunset by solid-phase microextraction (SPME coupled with gas chromatography (GC and gas chromatography/mass spectrometry (GC-MS. The results show that the optimal extraction conditions were obtained by using a DVB/CAR/PDMS fiber. A total of 31 compounds were identified, with the major compounds being geraniol, linalool and α-farnesene. P. Nobby’s Pacific Sunset had the highest odor concentration from 09:00 to 13:00 on the eighth day of storage. It was also found that in P. Nobby’s Pacific Sunset orchids the dorsal sepals and petals had the highest odor concentrations, whereas the column had the lowest.

  17. NASA Science Engagement Through "Sky Art"

    Science.gov (United States)

    Bethea, K. L.; Damadeo, K.

    2013-12-01

    Sky Art is a NASA-funded online community where the public can share in the beauty of nature and the science behind it. At the center of Sky Art is a gallery of amateur sky photos submitted by users that are related to NASA Earth science mission research areas. Through their submissions, amateur photographers from around the world are engaged in the process of making observations, or taking pictures, of the sky just like many NASA science instruments. By submitting their pictures and engaging in the online community discussions and interactions with NASA scientists, users make the connection between the beauty of nature and atmospheric science. Sky Art is a gateway for interaction and information aimed at drawing excitement and interest in atmospheric phenomena including sunrises, sunsets, moonrises, moonsets, and aerosols, each of which correlates to a NASA science mission. Educating the public on atmospheric science topics in an informal way is a central goal of Sky Art. NASA science is included in the community through interaction from scientists, NASA images, and blog posts on science concepts derived from the images. Additionally, the website connects educators through the formal education pathway where science concepts are taught through activities and lessons that align with national learning standards. Sky Art was conceived as part of the Education and Public Outreach program of the SAGE III on ISS mission. There are currently three other NASA mission involved with Sky Art: CALIPSO, GPM, and CLARREO. This paper will discuss the process of developing the Sky Art online website, the challenges of growing a community of users, as well as the use of social media and mobile applications in science outreach and education.

  18. Triggered lightning sky waves, return stroke modeling, and ionosphere effective height

    Science.gov (United States)

    Carvalho, F. L.; Uman, M. A.; Jordan, D. M.; Hill, J. D.; Cummer, S. A.; Kotovsky, D. A.; Moore, R. C.

    2017-03-01

    Ground waves and sky waves measured 209 km and 250 km south of six triggered lightning flashes containing 30 strokes that occurred in the half-hour before sunset on 27 August 2015 are presented and analyzed. We use a cross-correlation technique to find the ionospheric effective reflection height and compare our results to previous techniques that calculate effective height based on the time delay between ground wave and sky wave time domain features. From the first flash to the last flash there is, on average, a 1.6 km increase in effective ionospheric height, whereas no change in effective ionospheric height can be discerned along the individual strokes of a given flash. We show to what extent the triggered lightning radiation source can be described (using channel-base current, channel geometry, and channel luminosity versus time and height) and speculate that a well-characterized source could allow a more accurate determination of the electromagnetic fields radiated toward the ionosphere than has been done to date. We show that both channel geometry and the change in return stroke current amplitude and waveshape with channel height (inferred from measured channel luminosity versus height and time) determine the waveshape of the ground wave (and presumably the upward propagating wave that results in the sky wave) and that the waveshape of the ground wave does not appear to be related to the current versus time waveform measured at the channel base other than a roughly linear relationship between the two peak values.

  19. 78 FR 56811 - National Organic Program-Sunset Process

    Science.gov (United States)

    2013-09-16

    ... Agricultural Marketing Service 7 CFR Part 205 National Organic Program--Sunset Process AGENCY: Agricultural... Secretary and the Agricultural Marketing Service's (AMS) National Organic Program (NOP) will use to complete... marketing of organic products. How does this Sunset Process enhance public participation? Since the...

  20. Equatorial F region neutral winds and shears near sunset measured with chemical release techniques

    Science.gov (United States)

    Kiene, A.; Larsen, M. F.; Kudeki, E.

    2015-10-01

    The period near sunset is a dynamic and critical time for the daily development of the equatorial nighttime ionosphere and the instabilities that occur there. It is during these hours that the preconditions necessary for the later development of Equatorial Spread F (ESF) plasma instabilities occur. The neutral dynamics of the sunset ionosphere are also of critical importance to the generation of currents and electric fields; however, the behavior of the neutrals is experimentally understood primarily through very limited single-altitude measurements or measurements that provide weighted altitude means of the winds as a function of time. To date, there have been very few vertically resolved neutral wind measurements in the F region at sunset. We present two sets of sounding rocket chemical release measurements, one from a launch in the Marshall Islands on Kwajalein atoll and one from Alcantara, Brazil. Analysis of the release motions has yielded vertically resolved neutral wind profiles that show both the mean horizontal winds and the vertical shears in the winds. In both experiments, we observe significant vertical gradients in the zonal wind that are unexpected by classical assumptions about the behavior of the neutral wind at these altitudes at sunset near the geomagnetic equator.

  1. Nature's Late-Night Light Shows

    Science.gov (United States)

    Peterson, Carolyn Collins

    2002-09-01

    In addition to stars and planets, there are other interesting lights to be seen in the night sky. The northern and southern lights, called the aurora borealis and aurora australis, are created by charged particles from the Sun reacting in Earth's magnetic field. Night-shining clouds or noctilucent clouds appear at evening twilight as a result of water vapor in the polar mesosphere. Zodiacal light can be seen stretching up from the horizon after sunset or before sunrise.

  2. Dark-Skies Awareness

    Science.gov (United States)

    Walker, Constance E.

    2009-05-01

    The arc of the Milky Way seen from a truly dark location is part of our planet's natural heritage. More than one fifth of the world population, two thirds of the United States population and one half of the European Union population have already lost naked eye visibility of the Milky Way. This loss, caused by light pollution, is a serious and growing issue that impacts astronomical research, the economy, ecology, energy conservation, human health, public safety and our shared ability to see the night sky. For this reason, "Dark Skies” is a cornerstone project of the International Year of Astronomy. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people worldwide involved in a variety of programs that: 1. Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking on Facebook and MySpace, a Second Life presence) 2. Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Nights in the (National) Parks, Sidewalk Astronomy) 3. Organize events in the arts (e.g., a photography contest) 4. Involve citizen-scientists in naked-eye and digital-meter star hunting programs (e.g., GLOBE at Night, "How Many Stars?", the Great World Wide Star Count and the radio frequency interference equivalent: "Quiet Skies") and 5. Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security, and astronomy (e.g., The Starlight Initiative, World Night in Defense of Starlight, International Dark Sky Week, International Dark-Sky Communities, Earth Hour, The Great Switch Out, a traveling exhibit, downloadable posters and brochures). The presentation will provide an update, describe how people can become involved and take a look ahead at the program's sustainability. For more information, visit www.darkskiesawareness.org.

  3. Decoloration of Azo Dye Sunset Yellow by a Coaxial Insulated-Rod-to-Cylinder Underwater Streamer Discharge System

    Institute of Scientific and Technical Information of China (English)

    温小琼; 王明; 丁振峰; 刘贵师

    2012-01-01

    A coaxial insulated-rod-to-cylinder underwater streamer discharge system capable of injecting plasma into a large volume of water was developed and employed to decolorize azo dye sunset yellow. The rod type anode was covered by an insulator tube with a wall thickness of 0.4 mm. A series of slits with a width of 20 μm to 80 μm and a length of about 4 mm were cut onto the wall of the insulator tube. Depending on the solution conductivity, a cylindrical discharge region with a length of 60 mm and a wall thickness of 5 mm to 11 mm forms in the reactor. The influence of the solution conductivity, pH and pulse frequency on the decoloration of sunset yellow was investigated. The results show that the solution conductivity has little effect, while the solution pH and the pulse frequency have significant influence on the decoloration rate of sunset yellow. The decoloration rate of sunset yellow is increased with the increase in pulse frequency. A lower pH in solution promotes the decoloration of sunset yellow while a higher pH inhibits it.

  4. Sunset science. III. Visual adaptation and green flashes.

    Science.gov (United States)

    Young, A T

    2000-12-01

    Photographs of green flashes do not preclude a role for physiological effects in these phenomena. While green flashes are certainly not after-images, there is compelling evidence that adaptation in the visual system strongly affects the perceived color of most sunset green flashes. Furthermore, the retinal image of the setting Sun is usually bright enough to bleach most of the red-sensitive photopigment in a few seconds, making the yellow stage of a sunset flash appear green. Even in air so hazy that no green light reaches the eye, a yellow flash may occur and appear green. Many, but not all, visual observations of sunset green flashes are of this yellow flash. The yellow portion of sunset green flashes helps explain their reported durations, which exceed those expected for the appearance of green light alone.

  5. Observational Accuracy of Sunrise and Sunset Times in the Sixth Century China

    Institute of Scientific and Technical Information of China (English)

    Yong Li

    2006-01-01

    The Daye Calendar was compiled in AD 597 in the Sui Dynasty. We investigate the records of sunrise and sunset times on the 24 solar-term days in the calendar. By converting the ancient Chinese time units, Chen, Ke and Fen to hour, minute and second, and carrying out a comparison between the ancient records and values computed with modern astronomical theory, we find that the accuracy of solar measurements in the Sui period is remarkably high:for sunrise times, the average absolute deviation is 3.63 min (this value can be further reduced to 3.03 min when erroneous data are excluded), and for sunset times it is 3.48 min. We also find that the observed sunrise and sunset times are strictly symmetrically distributed with respect to both the Winter Solstice and the Summer Solstice, with their deviations showing a similar symmetrical distribution as well. We give a discussion on the date of observation, the feature of the data, and possible reasons of the deviation.

  6. Mining the Blazar Sky

    CERN Document Server

    Padovani, P; Padovani, Paolo; Giommi, Paolo

    2000-01-01

    We present the results of our methods to "mine" the blazar sky, i.e., select blazar candidates with very high efficiency. These are based on the cross-correlation between public radio and X-ray catalogs and have resulted in two surveys, the Deep X-ray Radio Blazar Survey (DXRBS) and the "Sedentary" BL Lac survey. We show that data mining is vital to select sizeable, deep samples of these rare active galactic nuclei and we touch upon the identification problems which deeper surveys will face.

  7. Elasticity of lyotropic chromonic liquid crystal Sunset Yellow probed by magnetic Frederiks transition

    Science.gov (United States)

    Zhou, Shuang; Nastishin, Yu. A.; Omelchenko, M. M.; Tortora, L.; Nazarenko, V. G.; Boiko, O. P.; Ostapenko, T.; Sprunt, S. N.; Gleeson, J. T.; Lavrentovich, O. D.

    2012-02-01

    By using director reorientation in the magnetic field, we determine the concentration and temperature dependencies of the splay K1, twist K2, and bend K3 elastic constants (normalized by the anisotropy of the diamagnetic susceptibility) for a nematic lyotropic chromonic liquid crystal (LCLC) Sunset Yellow. In a sharp contrast to thermotropic liquid crystals, the Frederiks effects in LCLC show a hysteresis, which is more pronounced at high concentration and low temperatures. We attribute the hysteresis to the changes in self-assembled structure of LCLC aggregates under the influence of field-imposed deformations.

  8. Dark Skies are a Universal Resource. So are Quiet Skies!

    Science.gov (United States)

    Maddalena, Ronald J.; Heatherly, S.

    2008-05-01

    You've just purchased your first telescope. But where to set it up? Certainly not a WalMart parking lot. Too much light pollution! In the same way that man-made light obscures our night sky and blinds ground-based optical telescopes, man-made radio signals blind radio telescopes as well. NRAO developed the Quiet Skies project to increase awareness of radio frequency interference (RFI) and radio astronomy in general by engaging students in local studies of RFI. To do that we created a sensitive detector which measures RFI. We produced 20 of these, and assembled kits containing detectors and supplementary materials for loan to schools. Students conduct experiments to measure the properties of RFI in their area, and input their measurements into a web-based data base. The Quiet Skies project is a perfect complement to the IYA Dark Skies Awareness initiative. We hope to place 500 Quiet Skies detectors into the field through outreach to museums and schools around the world. Should we be successful, we will sustain this global initiative via a continuing loan program. One day we hope to have a publicly generated image of the Earth which shows RFI much as the Earth at Night image illustrates light pollution. The poster will present the components of the project in detail, including our plans for IYA, and various low-cost alternative strategies for introducing RFI and radio astronomy to the public. We will share the results of some of the experiments already being performed by high school students. Development of the Quiet Skies project was funded by a NASA IDEAS grant. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  9. Sky monitoring with LOBSTER

    Science.gov (United States)

    Hudec, R.; Tichy, V.

    2014-12-01

    The X--ray sky monitoring represents valuable energy spectral extension to optical sky monitoring. Lobster--Eye all--sky monitors are able to provide relatively high sensitivity and good time resolution in the soft X--ray energy range up to 10 keV. The fine time resolution can be used to alert optical robotic telescopes for follow--up and multispectral analyzes in the visible light.

  10. PSM: Planck Sky Model

    Science.gov (United States)

    Ashdown, Mark; Aumont, Jonathan; Baccigalupi, Carlo; Banday, Anthony; Basak, Soumen; Bernard, Jean-Philippe; Betoule, Marc; Bouchet, François; Castex, Guillaume; Clements, Dave; Da Silva, Antonio; De Zotti, Gianfranco; Delabrouille, Jacques; Dickinson, Clive; Dodu, Fabrice; Dolag, Klaus; Elsner, Franz; Fauvet, Lauranne; Faÿ, Gilles; Giardino, Giovanna; Gonzalez-Nuevo, Joaquin; le Jeune, Maude; Leach, Samuel; Lesgourgues, Julien; Liguori, Michele; Macias, Juan; Massardi, Marcella; Matarrese, Sabino; Mazzotta, Pasquale; Melin, Jean-Baptiste; Miville-Deschênes, Marc-Antoine; Montier, Ludovic; Mottet, Sylvain; Paladini, Roberta; Partridge, Bruce; Piffaretti, Rocco; Prézeau, Gary; Prunet, Simon; Ricciardi, Sara; Roman, Matthieu; Schaefer, Bjorn; Toffolatti, Luigi

    2012-08-01

    The Planck Sky Model (PSM) is a global representation of the multi-component sky at frequencies ranging from a few GHz to a few THz. It summarizes in a synthetic way as much of our present knowledge as possible of the GHz sky. PSM is a complete and versatile set of programs and data that can be used for the simulation or the prediction of sky emission in the frequency range of typical CMB experiments, and in particular of the Planck sky mission. It was originally developed as part of the activities of Planck component separation Working Group (or "Working Group 2" - WG2), and of the ADAMIS team at APC. PSM gives users the opportunity to investigate the model in some depth: look at its parameters, visualize its predictions for all individual components in various formats, simulate sky emission compatible with a given parameter set, and observe the modeled sky with a synthetic instrument. In particular, it makes possible the simulation of sky emission maps as could be plausibly observed by Planck or other CMB experiments that can be used as inputs for the development and testing of data processing and analysis techniques.

  11. Under Summer Skies

    Science.gov (United States)

    Texley, Juliana

    2009-01-01

    There's no better way to celebrate 2009, the International Year of Astronomy, than by curling up with a good book under summer skies. To every civilization, in every age, the skies inspired imagination and scientific inquiry. There's no better place to start your summer reading than under their influence. Here are a few selections identified by…

  12. Global effects on Ionospheric Weather over the Indian subcontinent at Sunrise and Sunset

    Science.gov (United States)

    Basak, Tamal; Chakrabarti, S. K.; Pal, S.

    2010-10-01

    Study of Very Low Frequency (VLF) electromagnetic wave is very important for knowing the behavior of the Ionospheric layers due to Sunrise-Sunset, Earthquakes, Solar flares, Solar eclipses and other terrestrial and extra terrestrial radiations. We study the properties of the variation of the VLF signal strength theoretically all over Indian sub-continent. As an example, we concentrate on the VLF signal transmitted by Indian Naval Transmitter VTX at Vijayanarayanam (Latitude 08°23', Longitude 77°45') near the southern tip of Indian subcontinent. As has been noticed, several receiving stations placed during the VLF campaign in all over India, the VLF signal strength varies significantly with place and time. To understand the diurnal and seasonal variation of the received signal, a complete knowledge of physics of intensity distribution of the VLF signal is essential. The spatial variation of VLF signal plays an important role in selecting future VLF stations. In the wave-hop theoretical model presented here, horizontally stratified ionospheric layers have been considered. The VLF wave emitted by the transmitter has both the ground wave and the sky wave components. The ground wave attenuates during propagation. The sky wave component experiences reflections by the ionosphere on its way to the receiver and its attenuation depends on the degree of ionization. Intensity variation occurs at a given receiver location for interference among singly and multiply reflected waves. This has been simulated considering some simplified and justifiable assumptions. This spatial variation wave-hop theoretical model developed here has been compared with LWPC code generated results.

  13. Polarization-sensitive color mixing in the wing of the Madagascan sunset moth.

    Science.gov (United States)

    Yoshioka, Shinya; Kinoshita, Shuichi

    2007-03-05

    It is well known that the wing scales of butterflies and moths have elaborated microstructures that cause various optical effects. Structural colors occur when the microstructures have a size comparable with the wavelength of light. On the other hand, the wing scales of some species are structurally modified at a size much larger size than the light wavelength. Here we show for the Madagascan sunset moth that not only the microstructures but also the large-size modifications can play an important role in scale coloration. The wing of the sunset moth shows a striking iridescence that is caused by the air-cuticle multilayer structure inside the wing scales. Further, the scale itself is highly curved from its root to distal end. Owing to this strong curvature, a deep groove structure is formed between adjacent two rows of the regularly arranged scales. We find that this groove structure together with multilayer optical interference produces an unusual optical effect through an inter-scale reflection mechanism; the wing color changes depending on light polarization. A model is proposed that quantitatively describes this color change.

  14. 2014 Australasian sky guide

    CERN Document Server

    Lomb, Nick

    2013-01-01

    Compact, easy to use and reliable, this popular guide contains everything you need to know about the southern night sky with monthly astronomy maps, viewing tips and highlights, and details of all the year's exciting celestial events. Wherever you are in Australia or New Zealand, easy calculations allow you to estimate local rise and set times for the Sun, Moon and planets. The 2014 Australasian Sky Guide also provides information on the solar system, updated with the latest findings from space probes. Published annually since 1991, the Sky Guide continues to be a favourite with photographers,

  15. Source term assessment with ASTEC and associated uncertainty analysis using SUNSET tool

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier-Jabet, K., E-mail: karine.chevalier-jabet@irsn.fr; Cousin, F.; Cantrel, L.; Séropian, C.

    2014-06-01

    Several accidental scenarios have been simulated using the ASTEC integral IRSN-GRS code for a French 1300 MWe PWR, including several break sizes or locations, highlighting the effect of safety systems and of iodine chemistry in the reactor coolant system (RCS) and in the containment on iodine source term evaluations. Iodine chemistry in the RCS and in the containment is still subject to significant uncertainties and it is thus studied in on-going R and D programs. To assess the impact of uncertainties, ASTEC has been coupled to the IRSN uncertainty propagation and sensitivity analysis tool SUNSET. Focusing on a loss of feed-water of steam generator accident, ASTEC/SUNSET calculations have been performed to assess the effect of remaining uncertainties relative to iodine behaviour on the source term. Calculations show that the postulated lack of knowledge may impact the iodine source term in the environment by at least one decade, confirming the importance of the on-going R and D programs to improve the knowledge on iodine chemistry.

  16. Based on magnetic graphene oxide highly sensitive and selective imprinted sensor for determination of sunset yellow.

    Science.gov (United States)

    Li, Jianbo; Wang, Xiaojiao; Duan, Huimin; Wang, Yanhui; Bu, Yanan; Luo, Chuannan

    2016-01-15

    A new imprinted material based on β-cyclodextrin/ionic liquid/gold nanoparticles functionalized magnetic graphene oxide has been successfully synthesized and modified to the glassy carbon electrode surface to constructed imprinted electrochemical sensor to detect sunset yellow. The sensitivity and electrochemical response of the electrode can be improved by nanomaterials. The surface morphology and crystal structure of the hybrid nanomaterial has been characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy. The electrochemical behaviors of the hybrid nanomaterials based sensor were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimized conditions, the proposed electrochemical sensor showed a fast rebinding dynamics, which was successfully applied to sunset yellow detection with a wide linear range from 5.0×10(-9) to 2.0×10(-6)mol L(-1) and a detection limit of 2.0×10(-9)mol L(-1). The electrochemical sensor has been successfully applied in the determination of SY in spiked water samples, mirinda drink and minute maid, and the recoveries for the standards added are 97-105%.

  17. The conformal transformation of the night sky

    Science.gov (United States)

    Minguzzi, E.

    2016-12-01

    We give a simple differential geometric proof of the conformal transformation of the night sky under change of observer. The proof does not use the four dimensionality of spacetime or spinor methods. Furthermore, it really shows that the result does not depend on Lorentz transformations. This approach, by giving a transparent covariant expression to the conformal factor, shows that in most situations it is possible to define a thermal sky metric independent of the observer.

  18. Sunset Times, El Niño and Green Flashes

    Science.gov (United States)

    Liller, William

    2010-01-01

    On 637 occasions since 1988, precise times of sunset over the Pacific Ocean have been observed from a coastal site in central Chile (lat. 32.9º S.) at an elevation of approximately 120 meters. The original intent was to find if there was a connection between these times and the presence of the El Niño Oscillation event owing to the variation in atmospheric refraction that would be expected with a change in sea surface temperature. While no such effect was found, other phenomena were noted including the occurence of the green flash.

  19. Tropospheric haze and colors of the clear daytime sky.

    Science.gov (United States)

    Lee, Raymond L

    2015-02-01

    To casual observers, haze's visible effects on clear daytime skies may seem mundane: significant scattering by tropospheric aerosols visibly (1) reduces the luminance contrast of distant objects and (2) desaturates sky blueness. However, few published measurements of hazy-sky spectra and chromaticities exist to compare with these naked-eye observations. Hyperspectral imaging along sky meridians of clear and hazy skies at one inland and two coastal sites shows that they have characteristic colorimetric signatures of scattering and absorption by haze aerosols. In addition, a simple spectral transfer function and a second-order scattering model of skylight reveal the net spectral and colorimetric effects of haze.

  20. 75 FR 52509 - Potassium Permanganate from the People's Republic of China: Final Results of Expedited Sunset...

    Science.gov (United States)

    2010-08-26

    ... (``Sunset'') Review, 75 FR 23240 (May 3, 2010). On May 6, 2010, the Department received a notice of intent... International Trade Administration Potassium Permanganate from the People's Republic of China: Final Results of... Department of Commerce (``Department'') initiated a sunset review of the antidumping duty order on...

  1. 76 FR 3614 - Granular Polytetrafluoroethylene Resin From Japan: Final Results of Sunset Review and Revocation...

    Science.gov (United States)

    2011-01-20

    ... International Trade Administration Granular Polytetrafluoroethylene Resin From Japan: Final Results of Sunset... resin (``PTFE resin'') from Japan. See Initiation of Five-Year (``Sunset'') Review, 75 FR 67082..., the Department published an antidumping duty order on imports of PTFE resin from Japan....

  2. 33 CFR 117.821 - Atlantic Intracoastal Waterway, Albermarle Sound to Sunset Beach.

    Science.gov (United States)

    2010-07-01

    ..., Albermarle Sound to Sunset Beach. 117.821 Section 117.821 Navigation and Navigable Waters COAST GUARD... § 117.821 Atlantic Intracoastal Waterway, Albermarle Sound to Sunset Beach. (a) The drawbridges across... this paragraph: (1) Onslow Beach Swing Bridge, mile 240.7, at Cap Lejeune, NC, between 7 a.m. and 7...

  3. Sunset Policy dan Implikasinya terhadap Peningkatan Penerimaan Pajak Penghasilan di Daerah Istimewa Yogyakarta

    Directory of Open Access Journals (Sweden)

    Dahliana Hasan

    2012-02-01

    Full Text Available Sunset policy is a policy which decreases the amount of administrative sanction in the form of interest. This policy is governed by Article 37A Act Number 28 of 2007. The target of sunset policy is the taxpayer who has good faith either to admit having insufficient payment of income tax or to have willed to register a tax file number (NPWP. However, the time of sunset policy is limited; it takes only 1 (one year to apply the policy from 1 January to 31 December 2008. The research found that first, in tax law side sunset policy has the same legal meaning as kwijtschelding. The same legal meaning refers to the same characteristics found both in sunset policy and in kwijtschelding. Second, the internal target was not achieved until November 2008 as a result there was less contribution to the increasing amount of income tax revenue in DIY.

  4. Phases and structures of sunset yellow and disodium cromoglycate mixtures in water

    Science.gov (United States)

    Yamaguchi, Akihiro; Smith, Gregory P.; Yi, Youngwoo; Xu, Charles; Biffi, Silvia; Serra, Francesca; Bellini, Tommaso; Zhu, Chenhui; Clark, Noel A.

    2016-01-01

    We study phases and structures of mixtures of two representative chromonic liquid crystal materials, sunset yellow FCF (SSY) and disodium cromoglycate (DSCG), in water. A variety of combinations of isotropic, nematic (N ), and columnar (also called M ) phases are observed depending on their concentrations, and a phase diagram is made. We find a tendency for DSCG-rich regions to show higher-order phases while SSY-rich regions show lower-order ones. We observe uniform mesophases only when one of the materials is sparse in the N phases. Their miscibility in M phases is so low that essentially complete phase separation occurs. X-ray scattering and spectroscopy studies confirm that SSY and DSCG molecules do not mix when they form chromonic aggregates and neither do their aggregates when they form M phases.

  5. Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

    Science.gov (United States)

    Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Hazmin Sabri, Nor; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

    2017-03-01

    Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

  6. Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

    Science.gov (United States)

    Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Sabri, Nor Hazmin; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

    2017-03-01

    Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

  7. Sky coverage modeling for the whole sky for laser guide star multiconjugate adaptive optics.

    Science.gov (United States)

    Wang, Lianqi; Andersen, David; Ellerbroek, Brent

    2012-06-01

    The scientific productivity of laser guide star adaptive optics systems strongly depends on the sky coverage, which describes the probability of finding natural guide stars for the tip/tilt wavefront sensor(s) to achieve a certain performance. Knowledge of the sky coverage is also important for astronomers planning their observations. In this paper, we present an efficient method to compute the sky coverage for the laser guide star multiconjugate adaptive optics system, the Narrow Field Infrared Adaptive Optics System (NFIRAOS), being designed for the Thirty Meter Telescope project. We show that NFIRAOS can achieve more than 70% sky coverage over most of the accessible sky with the requirement of 191 nm total rms wavefront.

  8. Fireballs in the Sky

    Science.gov (United States)

    Day, B. H.; Bland, P.

    2016-12-01

    Fireballs in the Sky is an innovative Australian citizen science program that connects the public with the research of the Desert Fireball Network (DFN). This research aims to understand the early workings of the solar system, and Fireballs in the Sky invites people around the world to learn about this science, contributing fireball sightings via a user-friendly app. To date, more than 23,000 people have downloaded the app world-wide and participated in planetary science. The Fireballs in the Sky app allows users to get involved with the Desert Fireball Network research, supplementing DFN observations and providing enhanced coverage by reporting their own meteor sightings to DFN scientists. Fireballs in the Sky reports are used to track the trajectories of meteors - from their orbit in space to where they might have landed on Earth. Led by Phil Bland at Curtin University in Australia, the Desert Fireball Network (DFN) uses automated observatories across Australia to triangulate trajectories of meteorites entering the atmosphere, determine pre-entry orbits, and pinpoint their fall positions. Each observatory is an autonomous intelligent imaging system, taking 1000×36Megapixel all-sky images throughout the night, using neural network algorithms to recognize events. They are capable of operating for 12 months in a harsh environment, and store all imagery collected. We developed a completely automated software pipeline for data reduction, and built a supercomputer database for storage, allowing us to process our entire archive. The DFN currently stands at 50 stations distributed across the Australian continent, covering an area of 2.5 million km^2. Working with DFN's partners at NASA's Solar System Exploration Research Virtual Institute, the team is expanding the network beyond Australia to locations around the world. Fireballs in the Sky allows a growing public base to learn about and participate in this exciting research.

  9. 2013 Australasian sky guide

    CERN Document Server

    Lomb, Nick

    2012-01-01

    Compact, easy to use and reliable, this popular guide contains everything you need to know about the southern night sky with monthly star maps, diagrams and details of all the year's exciting celestial events. Wherever you are in Australia or New Zealand, easy calculations allow you to determine when the Sun, Moon and planets will rise and set throughout the year. Also included is information on the latest astronomical findings from space probes and telescopes around the world. The Sky guide has been published annually by the Powerhouse Museum, Sydney, since 1991. It is recommended for photogr

  10. BATSE Sky Exposure

    CERN Document Server

    Hakkila, J; Pendleton, G N; Henze, W; McCollough, M L; Kommers, J M; Briggs, M S; Hakkila, Jon; Meegan, Charles A.; Pendleton, Geoffrey N.; Henze, William; Collough, Michael Mc; Kommers, Jefferson M.; Briggs, Michael S.

    1997-01-01

    Angular sky exposure is presented for a number of published BATSE gamma-ray burst catalogs. A new algorithm was required due to telemetry gaps resulting from onboard tape recorder failures; the new algorithm improves the 1B Catalog exposure calculation. The most influential effects limiting BATSE's exposure are (1) deadtime due to triggering, (2) sky blockage by the Earth, and (3) trigger disabling when the spacecraft is in the SAA and over other specific Earth locations. Exposure has improved during the CGRO mission as a result of decreased Solar flares and magnetospheric particle events.

  11. The ADS All Sky Survey

    Science.gov (United States)

    Goodman, Alyssa

    We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where

  12. The observer's sky atlas

    CERN Document Server

    Karkoschka, E

    2007-01-01

    This title includes a short introduction to observing, a thorough description of the star charts and tables, a glossary and much more. It is perfect for both the beginner and seasoned observer. It is fully revised edition of a best-selling and highly-praised sky atlas.

  13. The Big Sky inside

    Science.gov (United States)

    Adams, Earle; Ward, Tony J.; Vanek, Diana; Marra, Nancy; Hester, Carolyn; Knuth, Randy; Spangler, Todd; Jones, David; Henthorn, Melissa; Hammill, Brock; Smith, Paul; Salisbury, Rob; Reckin, Gene; Boulafentis, Johna

    2009-01-01

    The University of Montana (UM)-Missoula has implemented a problem-based program in which students perform scientific research focused on indoor air pollution. The Air Toxics Under the Big Sky program (Jones et al. 2007; Adams et al. 2008; Ward et al. 2008) provides a community-based framework for understanding the complex relationship between poor…

  14. Electricity in the Sky

    Institute of Scientific and Technical Information of China (English)

    杨宇清

    1995-01-01

    Without any warning, the stormy sky flashes ghostly white. Jagged branches connect the earth and clouds in an eerie electric web,then disappear.Seconds later a resounding thunderclap warns you that the storm’s center is just a few miles away.

  15. A night sky model.

    Science.gov (United States)

    Erpylev, N. P.; Smirnov, M. A.; Bagrov, A. V.

    A night sky model is proposed. It includes different components of light polution, such as solar twilight, moon scattered light, zodiacal light, Milky Way, air glow and artificial light pollution. The model is designed for calculating the efficiency of astronomical installations.

  16. Calibration of an all-sky camera for obtaining sky radiance at three wavelengths

    Science.gov (United States)

    Román, R.; Antón, M.; Cazorla, A.; de Miguel, A.; Olmo, F. J.; Bilbao, J.; Alados-Arboledas, L.

    2012-08-01

    This paper proposes a method to obtain spectral sky radiances, at three wavelengths (464, 534 and 626 nm), from hemispherical sky images. Images are registered with the All-Sky Imager installed at the Andalusian Center for Environmental Research (CEAMA) in Granada (Spain). The methodology followed in this work for the absolute calibration in radiance of this instrument is based on the comparison of its output measurements with modelled sky radiances derived from the LibRadtran/UVSPEC radiative transfer code under cloud-free conditions. Previously, in order to check the goodness of the simulated radiances, these are compared with experimental values recorded by a CIMEL sunphotometer. In general, modelled radiances are in agreement with experimental data, showing mean differences lower than 20% except for the pixels located next to the Sun position that show larger errors. The relationship between the output signal of the All-Sky Imager and the modelled sky radiances provides a calibration matrix for each image. The variability of the matrix coefficients is analyzed, showing no significant changes along a period of 5 months. Therefore, a unique calibration matrix per channel is obtained for all selected images (a total of 705 images per channel). Camera radiances are compared with CIMEL radiances, finding mean absolute differences between 2% and 15% except for pixels near to the Sun and high scattering angles. We apply these calibration matrices to three images in order to study the sky radiance distributions for three different sky conditions: cloudless, overcast and partially cloudy. Horizon brightening under cloudless conditions has been observed together with the enhancement effect of individual clouds on sky radiance.

  17. Calibration of an all-sky camera for obtaining sky radiance at three wavelengths

    Directory of Open Access Journals (Sweden)

    R. Román

    2012-02-01

    Full Text Available This paper proposes a method to obtain spectral sky radiances, at three wavelengths (464, 534 and 626 nm, from hemispherical sky images. Images are registered with an All-Sky Imager installed at the Andalusian Center for Environmental Research (CEAMA in Granada (Spain. The methodology followed in this work for the absolute calibration in radiance of this instrument is based on the comparison of its output measurements with modelled sky radiances derived from the Libradtran/UVSPEC radiative transfer code under cloud-free conditions. Previously, in order to check the goodness of the simulated radiances, these are compared with experimental values recorded by a CIMEL sunphotometer. In general, modelled radiances are in agreement with experimental data, showing mean differences lower than 15% except for the pixels located next to the sun position that show larger errors.

    The comparison between the output signal of the All-Sky Imager and the modelled sky radiances provides a calibration matrix for each image. The variability of the matrix coefficients is analyzed, showing no significant changes along a period of 5 months. Therefore, a unique calibration matrix per channel is obtained for all selected images (a total of 705 images per channel. Camera radiances are compared with CIMEL radiances, finding mean absolute differences between 2% and 15% except for pixels near to the Sun and high zenith angles. We apply these calibration matrices to three images in order to study the sky radiance distributions for three different sky conditions: cloudless, overcast and partially cloudy. Horizon brightening under cloudless conditions has been observed together with the enhancement effect of individual clouds on sky radiance.

  18. An analytic approach to sunset diagrams in chiral perturbation theory: Theory and practice

    Energy Technology Data Exchange (ETDEWEB)

    Ananthanarayan, B.; Ghosh, Shayan [Indian Institute of Science, Centre for High Energy Physics, Karnataka (India); Bijnens, Johan [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden); Hebbar, Aditya [Indian Institute of Science, Centre for High Energy Physics, Karnataka (India); University of Delaware, Department of Physics and Astronomy, Newark, DE (United States)

    2016-12-15

    We demonstrate the use of several code implementations of the Mellin-Barnes method available in the public domain to derive analytic expressions for the sunset diagrams that arise in the two-loop contribution to the pion mass and decay constant in three-flavoured chiral perturbation theory. We also provide results for all possible two mass configurations of the sunset integral, and derive a new one-dimensional integral representation for the one mass sunset integral with arbitrary external momentum. Thoroughly annotated Mathematica notebooks are provided as ancillary files in the Electronic Supplementary Material to this paper, which may serve as pedagogical supplements to the methods described in this paper. (orig.)

  19. All Sky Camera instrument for night sky monitoring

    CERN Document Server

    Mandat, Dusan; Hrabovsky, Miroslav; Schovanek, Petr; Palatka, Miroslav; Travnicek, Petr; Prouza, Michael; Ebr, Jan

    2014-01-01

    The All Sky Camera (ASC) was developed as an universal device for a monitoring of the night sky quality and night sky background measurement. ASC system consists of an astronomical CCD camera, a fish eye lens, a control computer and associated electronics. The measurement is carried out during astronomical twilight. The analysis results are the cloud fraction (the percentage of the sky covered by clouds), night sky brightness (in mag/arcsec2) and light background in the field of view of the camera. The analysis of the cloud fraction is based on the astrometry (comparison to catalogue positions) of the observed stars.

  20. Serological Changes Induced by Blend of Sunset Yellow, Metanil Yellow and Tartrazine in Swiss Albino Rat, Rattus Norvegicus

    OpenAIRE

    Saxena, Beenam; Sharma, Shiv

    2014-01-01

    Objective: The present study was carried out to evaluate the toxic effect of blend of some food colors on Swiss albino rats. Materials and Methods: A blend (1:1:1) of sunset yellow, metanil yellow and tartrazine showed additive effects on serological parameters which indicate that addition of these dye together in food stuff may give rise to more toxic effects than are produced by each dye individually. Animals were divided into four groups (I, II, III, and IV). First group was treated as con...

  1. Skycorr: A general tool for spectroscopic sky subtraction

    CERN Document Server

    Noll, S; Kimeswenger, S; Barden, M; Jones, A M; Modigliani, A; Szyszka, C; Taylor, J

    2014-01-01

    Airglow emission lines, which dominate the optical-to-near-IR sky radiation, show strong, line-dependent variability on various time scales. Therefore, the subtraction of the sky background in the affected wavelength regime becomes a problem if plain sky spectra have to be taken at a different time as the astronomical data. A solution of this issue is the physically motivated scaling of the airglow lines in the plain sky data to fit the sky lines in the object spectrum. We have developed a corresponding instrument-independent approach based on one-dimensional spectra. Our code skycorr separates sky lines and sky/object continuum by an iterative approach involving a line finder and airglow line data. The sky lines are grouped according to their expected variability. The line groups in the sky data are then scaled to fit the sky in the science data. Required pixel-specific weights for overlapping groups are taken from a comprehensive airglow model. Deviations in the wavelength calibration are corrected by fitti...

  2. Dark Skies: Local Success, Global Challenge

    Science.gov (United States)

    Lockwood, G. W.

    2009-01-01

    The Flagstaff, Arizona 1987 lighting code reduced the growth rate of man-made sky glow by a third. Components of the code include requirements for full cutoff lighting, lumens per acre limits in radial zones around observatories, and use of low-pressure sodium monochromatic lighting for roadways and parking lots. Broad public acceptance of Flagstaff's lighting code demonstrates that dark sky preservation has significant appeal and few visibility or public safety negatives. An inventory by C. Luginbuhl et al. of the light output and shielding of a sampling of various zoning categories (municipal, commercial, apartments, single-family residences, roadways, sports facilities, industrial, etc.), extrapolated over the entire city, yields a total output of 139 million lumens. Commercial and industrial sources account for 62% of the total. Outdoor sports lighting increases the total by 24% on summer evenings. Flagstaff's per capita lumen output is 2.5 times greater than the nominal 1,000 lumens per capita assumed by R. Garstang in his early sky glow modeling work. We resolved the discrepancy with respect to Flagstaff's measured sky glow using an improved model that includes substantial near ground attenuation by foliage and structures. A 2008 university study shows that astronomy contributes $250M annually to Arizona's economy. Another study showed that the application of lighting codes throughout Arizona could reduce energy consumption significantly. An ongoing effort led by observatory directors statewide will encourage lighting controls in currently unregulated metropolitan areas whose growing sky glow threatens observatory facilities more than 100 miles away. The national press (New York Times, the New Yorker, the Economist, USA Today, etc.) have publicized dark sky issues but frequent repetition of the essential message and vigorous action will be required to steer society toward darker skies and less egregious waste.

  3. Dark Skies Rangers

    Science.gov (United States)

    Doran, Rosa

    2015-08-01

    Creating awareness about the importance of the protection of our dark skies is the main goal of the Dark Skies Rangers project, a joint effort from the NOAO and the Galileo Teacher Training Program. Hundreds of schools and thousands of students have been reached by this program. We will focus in particular on the experience being developed in Portugal where several municipalities have now received street light auditing produced by students with suggestions on how to enhance the energy efficiency of illumination of specific urban areas. In the International Year of Light we are investing our efforts in exporting the successful Portuguese experience to other countries. The recipe is simple: train teachers, engage students, foster the participation of local community and involve local authorities in the process. In this symposium we hope to draft the cookbook for the near future.

  4. Sacred Sky and Cyberspace

    Science.gov (United States)

    Clynes, F.

    2011-06-01

    The concept of the sacred world beyond the stars found expression in the works of Plato, into Gnosticism and was incorporated into Christianity where medieval images of the cosmos pictured the heavenly domain as beyond the stars. Today cyberspace literature abounds with descriptions of a transmundane space, a great Beyond. This talk looks at current views of cyberspace and asks if they are a re-packaging of the age-old concept of a sacred sky in a secular and technological format?

  5. 2012 Australasian sky guide

    CERN Document Server

    Lomb, Nick

    2011-01-01

    Compact, easy to use and reliable, this popular guide contains everything you need to know about the southern night sky with monthly star maps, diagrams and details of all the year's exciting celestial events. Wherever you are in Australia or New Zealand, easy calculations allow you to determine when the Sun, Moon and planets will rise and set throughout the year. Also included is information on the latest astronomical findings from space probes and telescopes around the world.

  6. Curiosities of the sky

    CERN Document Server

    Serviss, Garrett P

    2015-01-01

    Curiosities of the Sky is a newly annotated edition of the 1909 popular astronomy classic. All of the original text, photographs and diagrams are preserved, and new text added providing updates in the progress of astronomy since the book was first published. Garrett Serviss wrote with a firm understanding of the science of the period. He was also graced with a delightful imagination and unequaled power of poetic expression in describing the wonders and mysteries of the universe.

  7. The Sky at Night

    CERN Document Server

    Moore, Patrick

    2010-01-01

    For more than 50 years now Sir Patrick Moore has presented the BBC Television series Sky at Night; not a month has been missed – a record for any television series, and a record which may never be broken. Every three years or so a book is published covering the main events in both astronomy and space research. This is the 13th volume, not only a record of the programmes but also of the great advances and discoveries during the period covered - eclipses, comets, and the strange chemical lakes of Titan, for instance, but also anniversaries such as the fifteenth “birthday” of the Hubble Space Telescope, and not forgetting the programme celebrating the Sky at Night’s 50th year, attended by astronaut Piers Sellars and many others who appeared on the programme over the years. All the chapters are self-contained, and fully illustrated. In this new Sky at Night book you will find much to entertain you. It will appeal to amateurs and professionals alike.

  8. The Dynamic Infrared Sky

    Science.gov (United States)

    Kasliwal, Mansi M.; SPIRITS (Spitzer InfraRed Intensive Transients Survey) Team

    2017-01-01

    The dynamic infrared sky is hitherto largely unexplored. I will present the SPitzer InfraRed Intensive Transients Survey (SPIRITS) --- a systematic search of 194 nearby galaxies within 30 Mpc, on timescales ranging between a week to a year, to a depth of 20 mag with Spitzer's IRAC camera. SPIRITS has already uncovered over 95 explosive transients and over 1200 strong variables. Of these, 37 infrared transients are especially interesting as they have no optical counterparts whatsoever even with deep limits from Keck and HST. Interpretation of these new discoveries may include (i) the birth of massive binaries that drive shocks in their molecular cloud, (ii) stellar mergers with dusty winds, (iii) 8--10 solar mass stars experiencing e-capture induced collapse in their cores, (iv) enshrouded supernovae, or (v) formation of stellar mass black holes. SPIRITS reveals that the infrared sky is not just as dynamic as the optical sky; it also provides access to unique, elusive signatures in stellar astrophysics.

  9. Field Plot Points for Sunset Crater Volcano National Monument Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This spatial dataset in ESRI Coverage format maps field releve plot locations for the vegetation classification and descriptions of the vegetation map at Sunset...

  10. Spatial Vegetation Data for Sunset Crater Volcano National Monument Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This metadata is for the vegetation and land-use geo-spatial database for Sunset Crater Volcano National Monument and surrounding areas. The project is authorized as...

  11. Determination of sunset yellow in soft drinks based on fluorescence quenching of carbon dots

    Science.gov (United States)

    Yuan, Yusheng; Zhao, Xin; Qiao, Man; Zhu, Jinghui; Liu, Shaopu; Yang, Jidong; Hu, Xiaoli

    2016-10-01

    Fluorescent carbon dots was prepared by heating N-(2-hydroxyethyl)ethylene diaminetriacetic acid in air. The carbon dots were not only highly soluble in water but also uniform in size, and possessed strong blue fluorescence and excitation wavelength-dependent emission properties with the maximum excitation and emission wavelength at 366 nm and 423 nm, respectively. Food colorant sunset yellow whose excitation and emission wavelength at 303 nm and 430 nm could selectively quench the fluorescence of carbon dots, efficient fluorescent resonance energy transfer between the carbon dots and sunset yellow is achieved. This was exploited to design a method for the determination of sunset yellow in the concentration range from 0.3 to 8.0 μmol L- 1, with a limit of detection (3 σ/k) of 79.6 nmol L- 1. Furthermore the fluorimetric detection method was established and validated for sunset yellow in soft drinks samples with satisfactory results.

  12. Simplified Night Sky Display System

    Science.gov (United States)

    Castellano, Timothy P.

    2010-01-01

    A document describes a simple night sky display system that is portable, lightweight, and includes, at most, four components in its simplest configuration. The total volume of this system is no more than 10(sup 6) cm(sup 3) in a disassembled state, and weighs no more than 20 kilograms. The four basic components are a computer, a projector, a spherical light-reflecting first surface and mount, and a spherical second surface for display. The computer has temporary or permanent memory that contains at least one signal representing one or more images of a portion of the sky when viewed from an arbitrary position, and at a selected time. The first surface reflector is spherical and receives and reflects the image from the projector onto the second surface, which is shaped like a hemisphere. This system may be used to simulate selected portions of the night sky, preserving the appearance and kinesthetic sense of the celestial sphere surrounding the Earth or any other point in space. These points will then show motions of planets, stars, galaxies, nebulae, and comets that are visible from that position. The images may be motionless, or move with the passage of time. The array of images presented, and vantage points in space, are limited only by the computer software that is available, or can be developed. An optional approach is to have the screen (second surface) self-inflate by means of gas within the enclosed volume, and then self-regulate that gas in order to support itself without any other mechanical support.

  13. Google Sky: A Digital View of the Night Sky

    Science.gov (United States)

    Connolly, A. Scranton, R.; Ornduff, T.

    2008-11-01

    From its inception Astronomy has been a visual science, from careful observations of the sky using the naked eye, to the use of telescopes and photographs to map the distribution of stars and galaxies, to the current era of digital cameras that can image the sky over many decades of the electromagnetic spectrum. Sky in Google Earth (http://earth.google.com) and Google Sky (http://www.google.com/sky) continue this tradition, providing an intuitive visual interface to some of the largest astronomical imaging surveys of the sky. Streaming multi-color imagery, catalogs, time domain data, as well as annotating interesting astronomical sources and events with placemarks, podcasts and videos, Sky provides a panchromatic view of the universe accessible to anyone with a computer. Beyond a simple exploration of the sky Google Sky enables users to create and share content with others around the world. With an open interface available on Linux, Mac OS X and Windows, and translations of the content into over 20 different languages we present Sky as the embodiment of a virtual telescope for discovery and sharing the excitement of astronomy and science as a whole.

  14. ANALISIS SIKAP DAN PERILAKU KONSUMEN TERHADAP PEMILIHAN RUMAH TINGGAL PADA KAWASAN SUNSET GARDEN DI KOTA DENPASAR, BALI

    Directory of Open Access Journals (Sweden)

    I K. Ade Siswanta

    2014-02-01

    Full Text Available The research is motivated by the more selective consumers in choosing a house which impact on changes in market conditions ongoing. Developers should anticipate factors that influence changes in market conditions, such as attitudes and behaviors of consumers in choosing a house. One excample of this condition is development of Sunset Garden area located at Jalan Pura Mertasari Sunset Road, Denpasar, Bali which is this properties are able to attract consumers to buy houses in this area although this price of the house is quite expensive. Therefore, the research was conducted to determine factors that are considered in the selection of residential, consumer attitudes and behavior on the selection of a house and the relationship of consumer characteristics and attributes of products offered in this area. This study used research instruments such as questionnaires to obtain information on the characteristics of respondents and the four components of the attitudes and behavior of the level of confidence, the level of evaluation, the level of normative beliefs and motivation levels. The data analysis technique used is a factor analysis to identify the factors considered in choosing a house, attitudes and behavior analysis with Fishbein method and contingency coefficient analysis to determine the magnitude of the relationship variable product attributes and consumer characteristics. The results of this study indicate the factors that affect the house is 5 (five factors, they are the location and the legality factors, supporting facilities factors, physical factors, factor values, and environmental factors. Attitudes and behavior are shown in choosing a house on Sunset Garden Zone fall into this category good enough. The results showed that there is a relationship between consumer characteristics and attributes of the product which the consumer's income level has the strongest ties to the variable price of the product.

  15. Response of a free-flying songbird to an experimental shift of the light polarization pattern around sunset.

    Science.gov (United States)

    Schmaljohann, Heiko; Rautenberg, Tobias; Muheim, Rachel; Naef-Daenzer, Beat; Bairlein, Franz

    2013-04-15

    The magnetic field, the sun, the stars and the polarization pattern of visible light during twilight are important cues for orientation in nocturnally migrating songbirds. As these cues change with time and location on Earth, the polarization pattern was put forward as a likely key reference system calibrating the other compass systems. Whether this applies generally to migratory birds is, however, controversially discussed. We used an experimental approach in free-flying birds to study the role of polarization for their departure direction in autumn. Experimental birds experienced a 90 deg shift of the band of maximum polarization during sunset, whereas control birds experienced the polarization pattern as under natural conditions. Full view of the sunset cues near the horizon was provided during the cue conflict exposure. Here we show that both the experimental and the control birds being released after nautical twilight departed consistently towards south-southeast. Radiotelemetry allowed tracking of the first 15 km of the birds' outward journey, thus the intrinsic migration direction as chosen by the birds was measured. We found no recalibration of the magnetic compass after pre-exposure to a cue conflict between the natural magnetic field and the artificially shifted polarization pattern at sunset. The lacking difference in the departure direction of both groups may suggest that birds did not recalibrate any of the compass systems during the experiment. As free-flying migrants can use all available orientation cues after release, it remains unknown whether our birds might have used the magnetic and/or star compass to determine their departure direction.

  16. Wind direction variability in Afternoon and Sunset Turbulence

    Science.gov (United States)

    Nilsson, Erik; Lothon, Marie; Lohou, Fabienne; Mahrt, Larry

    2014-05-01

    Understanding wind direction (WD) variability better is important for several reasons. Air pollution models need information about how variable wind direction is in different conditions (Davies and Thomson 1999). Accurate predictions of dispersion are important for human health and safety and allow for adaptation planning (Nagle et al. 2011). Other applications include horizontal diffusion, efficiency and fatigue of wind machines and air-sea interaction (Mahrt 2011). Most studies of wind direction variability have focused on nocturnal conditions because of greater variability in light winds. Modelling WD variability in transition periods when both mean wind speed and variance of the wind components are in a state of change can, however, also be very challenging and has not been the focus of earlier studies. The evening transitioning to the nocturnal boundary layer can play an important role in the diffusion process of pollutants and scalars emitted at surface and transported within the atmosphere. The Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign that took place in southern France in June and July 2011 focused on the decaying turbulence of the late afternoon boundary layer and related issues (Lothon et al. 2012). We analyse field measurements from BLLAST to investigate WD variability in the evening transition period. Standard deviations of horizontal wind direction fluctuations in the lowest 60 m of the boundary layer have been examined for dependence on mean wind speed, higher order moments and averaging time. Measurement results are interpreted using measured and idealized probability density functions of horizontal wind vectors. These are also used to develop analytical functions describing how WD variability depends on wind speed, variance and other controlling factors in the atmospheric boundary layer. References: Davies B.M., Thomson D.J., 1999. Comparison of some parameterizations of wind direction variability with observations

  17. Static Filtered Sky Color Constancy

    Directory of Open Access Journals (Sweden)

    Ali Alkhalifah

    2016-05-01

    Full Text Available In Computer Vision, the sky color is used for lighting correction, image color enhancement, horizon alignment, image indexing, and outdoor image classification and in many other applications. In this article, for robust color based sky segmentation and detection, usage of lighting correction for sky color detection is investigated. As such, the impact of color constancy on sky color detection algorithms is evaluated and investigated. The color correction (constancy algorithms used includes Gray-Edge (GE, Gray-World (GW, Max-RGB (MRGB and Shades-of-Gray (SG. The algorithms GE, GW, MRGB, and SG, are tested on the static filtered sky modeling. The static filter is developed in the LAB color space. This evaluation and analysis is essential for detection scenarios, especially, color based object detection in outdoor scenes. From the results, it is concluded that the color constancy before sky color detection using LAB static filters has the potential of improving sky color detection performance. However, the application of the color constancy can impart adverse effects on the detection results. For images, the color constancy algorithms depict a compact and stable representative of the sky chroma loci, however, the sky color locus might have a shifting and deviation in a particular color representation. Since the sky static filters are using the static chromatic values, different results can be obtained by applying color constancy algorithms on various datasets.

  18. Gamma-sky.net: Portal to the gamma-ray sky

    Science.gov (United States)

    Voruganti, Arjun; Deil, Christoph; Donath, Axel; King, Johannes

    2017-01-01

    http://gamma-sky.net is a novel interactive website designed for exploring the gamma-ray sky. The Map View portion of the site is powered by the Aladin Lite sky atlas, providing a scalable survey image tesselated onto a three-dimensional sphere. The map allows for interactive pan and zoom navigation as well as search queries by sky position or object name. The default image overlay shows the gamma-ray sky observed by the Fermi-LAT gamma-ray space telescope. Other survey images (e.g. Planck microwave images in low/high frequency bands, ROSAT X-ray image) are available for comparison with the gamma-ray data. Sources from major gamma-ray source catalogs of interest (Fermi-LAT 2FHL, 3FGL and a TeV source catalog) are overlaid over the sky map as markers. Clicking on a given source shows basic information in a popup, and detailed pages for every source are available via the Catalog View component of the website, including information such as source classification, spectrum and light-curve plots, and literature references. We intend for gamma-sky.net to be applicable for both professional astronomers as well as the general public. The website started in early June 2016 and is being developed as an open-source, open data project on GitHub (https://github.com/gammapy/gamma-sky). We plan to extend it to display more gamma-ray and multi-wavelength data. Feedback and contributions are very welcome!

  19. Hyperspectral all-sky imaging of auroras.

    Science.gov (United States)

    Sigernes, Fred; Ivanov, Yuriy; Chernouss, Sergey; Trondsen, Trond; Roldugin, Alexey; Fedorenko, Yury; Kozelov, Boris; Kirillov, Andrey; Kornilov, Ilia; Safargaleev, Vladimir; Holmen, Silje; Dyrland, Margit; Lorentzen, Dag; Baddeley, Lisa

    2012-12-03

    A prototype auroral hyperspectral all-sky camera has been constructed and tested. It uses electro-optical tunable filters to image the night sky as a function of wavelength throughout the visible spectrum with no moving mechanical parts. The core optical system includes a new high power all-sky lens with F-number equal to f/1.1. The camera has been tested at the Kjell Henriksen Observatory (KHO) during the auroral season of 2011/2012. It detects all sub classes of aurora above ~½ of the sub visual 1kR green intensity threshold at an exposure time of only one second. Supervised classification of the hyperspectral data shows promise as a new method to process and identify auroral forms.

  20. Sonneberg Sky Patrol Archive - Photometric Analysis

    CERN Document Server

    Spasovic, Milan; Lange, Christian; Jovanovic, Dragan; Schrimpf, Andreas

    2016-01-01

    The Sonneberg Sky Patrol archive so far has not yet been analyzed systematically. In this paper we present first steps towards an automated photometric analysis aiming at the search for variable stars and transient phenomena like novae. Early works on the sky patrol plates showed that photometric accuracy can be enhanced with fitting algorithms. The procedure used was a manually supported click-and-fit-routine, not suitable for automatic analysis of vast amount of photographic plates. We will present our progress on deconvolution of overlapping sources on the plates and compare photometric analysis using different methods. Our goal is to get light curves of sufficient quality from sky patrol plates, which can be classified with machine learning algorithms. The development of an automated scheme for finding transient events is in progress and the first results are very promising.

  1. Light pollution: Assessment of sky glow on two dark sky regions of Portugal.

    Science.gov (United States)

    Lima, Raul Cerveira; Pinto da Cunha, José; Peixinho, Nuno

    2016-01-01

    Artificial light at night (ALAN), producing light pollution (LP), is not a matter restricted to astronomy anymore. Light is part of modern societies and, as a consequence, the natural cycle day-night (bright-dark) has been interrupted in a large segment of the global population. There is increasing evidence that exposure to certain types of light at night and beyond threshold levels may produce hazardous effects to humans and the environment. The concept of "dark skies reserves" is a step forward in order to preserve the night sky and a means of enhancing public awareness of the problem of spread of light pollution worldwide. The aim of this study was to assess the skyglow at two sites in Portugal, the Peneda-Gerês National Park (PNPG) and the region now known as Dark Sky Alqueva Reserve. The latter site was classified as a "Starlight Tourism Destination" by the Starlight Foundation (the first in the world to achieve this classification) following a series of night sky measurements in situ described herein. The measurements at PNPG also contributed to the new set of regulations concerning light pollution at this national park. This study presents the first in situ systematic measurements of night sky brightness, showing that at the two sites the skies are mostly in levels 3 to 4 of the Bortle 9-level scale (with level 1 being the best achievable). The results indicate that the sources of light pollution and skyglow can be attributed predominantly to contamination from nearby urban regions.

  2. The Other Dark Sky

    Science.gov (United States)

    Pazmino, John

    In previous demonstrations of New York's elimination of luminous graffiti from its skies, I focused attention on large-scale projects in the showcase districts of Manhattan. Although these works earned passionate respect in the dark sky movement, they by the same token were disheartening. New York was in some quarters of the movement regarded more as an unachievable Shangri-La than as a role model to emulate. This presentation focuses on scenes of light abatement efforts in parts of New York which resemble other towns in scale and density. I photographed these scenes along a certain bus route in Brooklyn on my way home from work during October 2001. This route circulates through various "bedroom communities," each similar to a mid-size to large town elsewhere in the United States. The sujbects included individual structures - stores, banks, schools - and streetscapes mimicking downtowns. The latter protrayed a mix of atrocious and excellent lighting practice, being that these streets are in transition by the routine process of replacement and renovation. The fixtures used - box lamps, fluted or Fresnel globes, subdued headsigns, indirect lighting - are casually obtainable by property managers at local outlets for lighting apparatus. They are routinely offered to the property managers by storefront designers, security services, contractors, and the community improvement or betterment councils.

  3. Sun, Earth and Sky

    CERN Document Server

    Lang, Kenneth R

    2006-01-01

    This Second Edition of Sun, Earth and Sky updates the popular text by providing comprehensive accounts of the most recent discoveries made by five modern solar spacecraft during the past decade. Their instruments have used sound waves to peer deep into the Sun’s inner regions and measure the temperature of its central nuclear reactor, and extended our gaze far from the visible Sun to record energetic outbursts that threaten Earth. Breakthrough observations with the underground Sudbury Neutrino Observatory are also included, which explain the new physics of ghostly neutrinos and solve the problematic mismatch between the predicted and observed amounts of solar neutrinos. This new edition of Sun, Earth and Sky also describes our recent understanding of how the Sun’s outer atmosphere is heated to a million degrees, and just where the Sun’s continuous winds come from. As humans we are more intimately linked with our life-sustaining Sun than with any other astronomical object, and the new edition therefore p...

  4. Mauna Kea Sky Transparency from CFHT SkyProbe Data

    CERN Document Server

    Steinbring, Eric; Magnier, Eugene

    2008-01-01

    Nighttime sky transparency statistics on Mauna Kea are reported based on data from the Canada-France-Hawaii Telescope SkyProbe monitor. We focus on the period beginning with the start of MegaCam wide-field optical imager operations in 2003, and continuing for almost three years. Skies were clear enough to observe on 76% of those nights; attenuations were less than 0.2 magnitudes up to 60% of the time. An empirical model of cloud attenuation and duration is presented allowing us to further characterize the photometric conditions. This is a good fit tothe SkyProbe data, and indicates that Mauna Kea skies are truly photometric (without cloud) an average of 56% of the time, with moderate seasonal variation. Continuous monitoring of transparency during the night is necessary to overcome fluctuations in attenuation due to thin cloud.

  5. Faraday polarization fluctuations and their dependence on post sunset secondary maximum and amplitude scintillations at Delhi

    Directory of Open Access Journals (Sweden)

    J. K. Gupta

    Full Text Available VHF Faraday rotation (FR and amplitude scintillation data recorded simultaneously during May 1978–December 1980 at Delhi (28.63° N, 77.22° E; Dip 42.44° N is analyzed in order to study the Faraday polarization fluctuations (FPFs and their dependence on the occurrence of post sunset secondary maximum (PSSM and amplitude scintillations. It is noted that FPFs are observed only when both PSSM and scintillations also occur simultaneously. FPFs are observed only during winter and the equinoctial months of high sunspot years. FPFs events are associated with intense scintillation activity, which is characterized by sudden onsets and abrupt endings, and are observed one to three hours after the local sunset. When FPFs and scintillation data from Delhi is compared with the corresponding data from a still lower latitude station, Hyderabad (17.35° N, 78.45° E, it is found that the occurrence of FPFs and scintillations at Delhi is conditional to their prior occurrence at Hyderabad, which indicates their production by a plasma bubble and the as-sociated irregularities generated initially over the magnetic equator. In addition, FPFs and scintillation data for October 1979, when their occurrence was maximum, is also examined in relation to daytime (11:00 LT electrojet strength (EEj values and evening hour h’F from an equatorial location, Kodaikanal (10.3° N, 77.5° E. It is interesting to note that FPFs and scintillations are most likely observed when the EEj was 100 nT or more and h’F reaches around 500 km. These results show that EEj and evening hours h’F values over the magnetic equator are important parameters for predicting FPFs and scintillation activity at locations such as Delhi, where scintillation activity is much more intense as compared to the equatorial region due to the enhanced back-ground ionization due to the occurrence of PSSM.

    Key words. Ionosphere (equatorial ionosphere; ionospheric irregularities – Radio science

  6. Highly sensitive electrochemical determination of Sunset Yellow based on gold nanoparticles/graphene electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Yang, Beibei; Wang, Huiwen; Yang, Ping; Du, Yukou, E-mail: duyk@suda.edu.cn

    2015-09-17

    An electrochemical sensor was prepared using Au nanoparticles and reduced graphene successfully decorated on the glassy carbon electrode (Au/RGO/GCE) through an electrochemical method which was applied to detect Sunset Yellow (SY). The as-prepared electrode was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and electrochemical measurements. The results of cyclic voltammetry (CV) proved that Au/RGO/GCE had the highest catalytic activity for the oxidation of SY as compared with GCE, Au/GCE, and RGO/GCE. Differential pulse voltammetry (DPV) showed that the linear calibration curves for SY on Au/RGO/GCE in the range of 0.002 μM–109.14 μM, and the detection limit was estimated to be 2 nM (S/N = 3). These results suggested that the obtained Au/RGO/GCE was applied to detect SY with high sensitivity, low detection limit and good stability, which provided a promising future for the development of portable sensor in food additives. - Highlights: • An Au/RGO composite was fabricated by electrochemical deposition method. • The oxidation current of SY on the composition is up to 10 μA. • The detection range of SY is 0.002–109.14 μM with a detection limit of 2 nM.

  7. A Zinc Oxide Nanoflower-Based Electrochemical Sensor for Trace Detection of Sunset Yellow

    Science.gov (United States)

    Ya, Yu; Jiang, Cuiwen; Li, Tao; Liao, Jie; Fan, Yegeng; Wei, Yuning; Yan, Feiyan; Xie, Liping

    2017-01-01

    Zinc oxide nanoflower (ZnONF) was synthesized by a simple process and was used to construct a highly sensitive electrochemical sensor for the detection of sunset yellow (SY). Due to the large surface area and high accumulation efficiency of ZnONF, the ZnONF-modified carbon paste electrode (ZnONF/CPE) showed a strong enhancement effect on the electrochemical oxidation of SY. The electrochemical behaviors of SY were investigated using voltammetry with the ZnONF-based sensor. The optimized parameters included the amount of ZnONF, the accumulation time, and the pH value. Under optimal conditions, the oxidation peak current was linearly proportional to SY concentration in the range of 0.50–10 μg/L and 10–70 μg/L, while the detection limit was 0.10 μg/L (signal-to-noise ratio = 3). The proposed method was used to determine the amount of SY in soft drinks with recoveries of 97.5%–103%, and the results were in good agreement with the results obtained by high-performance liquid chromatography. PMID:28282900

  8. Multi-spectroscopic DNA interaction studies of sunset yellow food additive.

    Science.gov (United States)

    Kashanian, Soheila; Heidary Zeidali, Sahar; Omidfar, Kobra; Shahabadi, Nahid

    2012-12-01

    The use of food dyes is at least controversial due to their essential role. Synthetic color food additives occupy an important place in the food industry. Moreover many of them have been related to health problems mainly in children that are considered the most vulnerable group. The purpose of this work is to present spectrophotometric methods to analyze the interaction of native calf thymus DNA (CT-DNA) with sunset yellow (SY) at physiological pH. Considerable hyperchromism and no red shift with an intrinsic binding constant of 7 × 10(4 )M(-1) were observed in UV absorption band of SY. Binding constants of DNA with complex were calculated at different temperatures. Slow increase in specific viscosity of DNA, induced circular dichroism spectral changes, and no significant changes in the fluorescence of neutral red-DNA solutions in the presence of SY suggest that this molecule interacts with CT-DNA via groove binding mode. Furthermore, the enthalpy and entropy of the reaction between SY and CT-DNA showed that the reaction is exothermic and enthalpy favored (∆H = -58.19 kJ mol(-1); ΔS = -274.36 kJ mol(-1) ) which are other evidences to indicate that van der Waals interactions and hydrogen bonding are the main running forces in the binding of the mentioned molecule and mode of interaction with DNA.

  9. Close to the Sky

    Science.gov (United States)

    2007-11-01

    Today, a new ALMA outreach and educational book was publicly presented to city officials of San Pedro de Atacama in Chile, as part of the celebrations of the anniversary of the Andean village. ESO PR Photo 50a/07 ESO PR Photo 50a/07 A Useful Tool for Schools Entitled "Close to the sky: Biological heritage in the ALMA area", and edited in English and Spanish by ESO in Chile, the book collects unique on-site observations of the flora and fauna of the ALMA region performed by experts commissioned to investigate it and to provide key initiatives to protect it. "I thank the ALMA project for providing us a book that will surely be a good support for the education of children and youngsters of San Pedro de Atacama. Thanks to this publication, we expect our rich flora and fauna to be better known. I invite teachers and students to take advantage of this educational resource, which will be available in our schools", commented Ms. Sandra Berna, the Mayor of San Pedro de Atacama, who was given the book by representatives of the ALMA global collaboration project. Copies of the book 'Close to the sky' will be donated to all schools in the area, as a contribution to the education of students and young people in northern Chile. "From the very beginning of the project, ALMA construction has had a firm commitment to environment and local culture, protecting unique flora and fauna species and preserving old estancias belonging to the Likan Antai culture," said Jacques Lassalle, who represented ALMA at the hand-over. "Animals like the llama, the fox or the condor do not only live in the region where ALMA is now being built, but they are also key elements of the ancient Andean constellations. In this sense they are part of the same sky that will be explored by ALMA in the near future." ESO PR Photo 50c/07 ESO PR Photo 50c/07 Presentation of the ALMA book The ALMA Project is a giant, international observatory currently under construction on the high-altitude Chajnantor site in Chile

  10. Reconsideration of the temporary ADI and refined exposure assessment for Sunset Yellow FCF (E 110

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to food (ANS

    2014-07-01

    Full Text Available The Panel on Food Additives and Nutrient Sources added to Food (ANS Panel has previously provided a scientific opinion re-evaluating the safety of Sunset Yellow FCF (E 110 as a food additive in the EU and establishing a temporary acceptable daily intake (ADI of 1 mg/kg bw/day (EFSA ANS Panel, 2009. Following a request by the European Commission, the ANS Panel was asked to assess newly submitted data from a study conducted as a result of the recommendations contained in the 2009 opinion. In addition, EFSA was requested to carry out the refined exposure assessment of Sunset Yellow FCF. The new information assessed comprised an evaluation of the 28-day study report, the data considered by the Joint FAO/WHO Expert Committee on Food Additives (JECFA in its latest evaluation from 2011, and any additional toxicological information that had become available since the completion of the previous evaluation by the ANS Panel. The ANS Panel has considered that the newly submitted data from the 28-day study and the overall available toxicological database on Sunset Yellow FCF provides a basis to revise the established temporary ADI and concluded that, based on the NOAEL of 375 mg/kg bw/day from the long-term feeding study in rats and an uncertainty factor of 100, a new ADI for Sunset Yellow FCF of 4 mg/kg bw/day can be established, in agreement with the latest evaluation by JECFA. Exposure estimates for Sunset Yellow FCF based both on the currently authorised MPLs and reported use levels provided are well below the new ADI of 4 mg/kg bw/day for all population groups. Overall, the Panel concluded that, using data provided by the food industry and Member States, the reported uses and use levels of Sunset Yellow FCF (E 110 would not be of safety concern.

  11. Immunological studies on Amaranth, Sunset Yellow and Curcumin as food colouring agents in albino rats.

    Science.gov (United States)

    Hashem, Mohamed M; Atta, Attia H; Arbid, Mahmoud S; Nada, Somaia A; Asaad, Gihan Farag

    2010-06-01

    The use of food dyes is at least controversial because they are only of essential role. Moreover many of them have been related to health problems mainly in children that are considered a very vulnerable group. This study was carried out to investigate the effect of oral administration of Amaranth, Sunset Yellow and Curcumin for 4 weeks at doses of 47, 315 and 157.5 mg/kg b. wt. and after 2 weeks all animals were immunostimulated by intra peritoneal injection of sheep RBCs 10% (1 ml/rat). Body weight, relative body weight, total and differential leukocytes count, mononuclear cell count, delayed hypersensitivity, total protein and serum fractions were determined. Results revealed that oral administration of Amaranth, Sunset Yellow and Curcumin did not affect the body weight gain or the spleen weight. On the other hand Sunset Yellow and Curcumin significantly decreased the weight of thymus gland of the rats. Total leukocyte count were not affected while Amaranth and Curcumin-treated rats revealed a significant decrease in neutrophiles and monocytes and a compensatory increase in lymphocytes. Moreover, oral administration of Sunset Yellow revealed a significant decrease in monocyte percent. Amaranth, Sunset Yellow and Curcumin significantly decreased the delayed hyper sensitivity. Total serum protein, albumin, total globulin and albumin/globulin (A/G) ratio were not affected by administration of the colouring agents. Oral administration of Amaranth increases the density of albumin band. On the other hand oral administration of Curcumin decreases the density of the albumin band. Oral administration of any of the tested colouring agents did not change the density of globulin region as compared to control group. In conclusion we found that both synthetic (Amaranth and Sunset Yellow) and natural (Curcumin) colouring agents used at doses up to 10 times the acceptable daily intake exerted a depressing effect on the cellular but not humoral immune response.

  12. 75 FR 57051 - Notice of Intent To Prepare a Draft Environmental Impact Statement for the Sunset Area Community...

    Science.gov (United States)

    2010-09-17

    ... Environmental Impact Statement (EIS) for the redevelopment of the Sunset Terrace public housing community and... URBAN DEVELOPMENT Notice of Intent To Prepare a Draft Environmental Impact Statement for the Sunset Area...; environmental justice; historic/cultural resources; housing; land use; noise; parks and recreation; plants...

  13. 77 FR 58524 - Honey From Argentina; Final Results of Sunset Reviews and Revocation of Antidumping Duty and...

    Science.gov (United States)

    2012-09-21

    ... International Trade Administration Honey From Argentina; Final Results of Sunset Reviews and Revocation of...) initiated sunset reviews of the antidumping duty and countervailing duty orders on honey from Argentina.\\1... deadline, the Department is revoking the antidumping duty and countervailing duty orders on honey...

  14. 77 FR 59896 - Honey From the People's Republic of China: Final Results of Expedited Sunset Review of the...

    Science.gov (United States)

    2012-10-01

    ... International Trade Administration Honey From the People's Republic of China: Final Results of Expedited Sunset... the second five-year (``sunset'') review of the antidumping duty order on honey from the People's... Department finds that revocation of the antidumping duty order on honey from the PRC would be likely to...

  15. 76 FR 26242 - Paper Clips From the People's Republic of China: Final Results of Expedited Sunset Review of...

    Science.gov (United States)

    2011-05-06

    ... International Trade Administration Paper Clips From the People's Republic of China: Final Results of Expedited...'') initiated the third sunset review of the antidumping duty order on paper clips from the People's Republic of... expedited (120-day) sunset review of the antidumping duty order on paper clips from the PRC, pursuant...

  16. 76 FR 19747 - Solid Urea From the Russian Federation and Ukraine: Final Results of the Expedited Sunset Reviews...

    Science.gov (United States)

    2011-04-08

    ... International Trade Administration Solid Urea From the Russian Federation and Ukraine: Final Results of the...) initiated the third sunset reviews of the antidumping duty orders on solid urea from the Russian Federation... the notice of initiation of the sunset reviews of the antidumping duty orders \\1\\ on solid urea...

  17. Handing over the sunset. External factors influencing the establishment of water user associations in Uzbekistan: Evidence from Khorezm Province

    NARCIS (Netherlands)

    Wegerich, K.

    2010-01-01

    Recently, large-scale surface-water or canal irrigation systems have been termed ‘a sunset industry’ (Rijsberman 2003). Handing over this sunset industry by means of irrigation management transfer (IMT) policies and the creation of water user associations (WUAs) has three main objectives: to increas

  18. Handing over the sunset. External factors influencing the establishment of water user associations in Uzbekistan: Evidence from Khorezm Province

    NARCIS (Netherlands)

    Wegerich, K.

    2010-01-01

    Recently, large-scale surface-water or canal irrigation systems have been termed ‘a sunset industry’ (Rijsberman 2003). Handing over this sunset industry by means of irrigation management transfer (IMT) policies and the creation of water user associations (WUAs) has three main objectives: to

  19. 77 FR 10477 - Silicon Metal From the People's Republic of China: Final Results of the Expedited Third Sunset...

    Science.gov (United States)

    2012-02-22

    ... International Trade Administration Silicon Metal From the People's Republic of China: Final Results of the... (``the Department'') initiated the third sunset review of the antidumping duty order on silicon metal..., the Department conducted an expedited (120-day) sunset review of the antidumping duty order on...

  20. Digital all-sky polarization imaging of partly cloudy skies.

    Science.gov (United States)

    Pust, Nathan J; Shaw, Joseph A

    2008-12-01

    Clouds reduce the degree of linear polarization (DOLP) of skylight relative to that of a clear sky. Even thin subvisual clouds in the "twilight zone" between clouds and aerosols produce a drop in skylight DOLP long before clouds become visible in the sky. In contrast, the angle of polarization (AOP) of light scattered by a cloud in a partly cloudy sky remains the same as in the clear sky for most cases. In unique instances, though, select clouds display AOP signatures that are oriented 90 degrees from the clear-sky AOP. For these clouds, scattered light oriented parallel to the scattering plane dominates the perpendicularly polarized Rayleigh-scattered light between the instrument and the cloud. For liquid clouds, this effect may assist cloud particle size identification because it occurs only over a relatively limited range of particle radii that will scatter parallel polarized light. Images are shown from a digital all-sky-polarization imager to illustrate these effects. Images are also shown that provide validation of previously published theories for weak (approximately 2%) polarization parallel to the scattering plane for a 22 degrees halo.

  1. NRAO Makes Available VLA Sky Survey Maps

    Science.gov (United States)

    1994-06-01

    An original and comprehensive data set potentially full of scientific surprises now is available to astronomers, students and the public through the information superhighway. Radio images of the sky produced by the Very Large Array radio telescope -- one of the premier astronomical instruments in the world -- as part of a massive survey now are stored in an electronic repository avail- able over the Internet computer communications network. "Each of these sensitive new sky maps shows about a thou- sand radio-emitting objects, most of which have never been seen before," said Dr. J. J. Condon, leader of the National Radio As- tronomy Observatory (NRAO) survey team. "We are releasing them as soon as they are completed because they contain more data than we could possibly analyze by ourselves." "By using electronic distribution, we can open this tre- mendous resource of information for computer analysis by all as- tronomers immediately, without waiting for traditional publication," Condon added. The radio images are copyright NRAO/ AUI. Permission is granted for use of the material without charge for scholarly, educational and private non-commercial purposes. "It is entirely conceivable -- even probable -- that valuable discoveries will be made by students or amateur astrono- mers who devote the time to study these maps carefully," said team member Dr. W. D. Cotton. "Making this new information available electronically means that more people can participate in adding to its scientific value." The maps are a product of the NRAO VLA Sky Survey (NVSS), which began its observational phase in September of 1993 and will cover 82 percent of the sky when completed by the end of 1996. The NVSS is expected to produce a catalog of more than two million ra- dio-emitting objects in the sky, and it is the first sky survey sensitive to linearly polarized emission from radio sources beyond our own Milky Way galaxy. "The NVSS is being made as a service to the entire astronomical

  2. Sky cover from MFRSR observations

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-07-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  3. Reach the sky

    Science.gov (United States)

    Mariana Peicuti, Cristina

    2017-04-01

    I am working as primary teacher at Scoala Gimnaziala Dumbrava,Timis County, Romania & my pupils has 6 to 10 years old. I was&I am a main pillar in my community, always disseminating knowledge and experience to students, other teachers in the school area &Timis County.Astronomy is the must favorite subject of my students from my classes. They are very courious & always come to me with questions about Earth and Sky because Curriculum scientific disciplines provides too little information about Earth and Sky.I need to know more about how to teach space contents into my classes&what competencies can form in elementary school and also to share my experience to the others.As a result of participation at this meeting I want to attract as many students to astronomy,science/STEM disciplines&space technologies, to astronomy topics and exploration of outer space.Schools needs to be prepared for social life needs,new generations needs,on science/space technologies,which are one of the key points for developing the knowledge society.I intend to introduce new scientific activities as part of the existing curriculum.I am passionate about astronomy,I need to know new approaches and new ideas for primary because I think Science is very important in daily life. Here are some developed activities with pupils from K-2 grade levels wich I wish share with colleagues in Viena. Subject: MATHEMATICS. Primary Topic: MEASUREMENT : -+= ☼ Rockets by Size. Students cut out,color and sequence paper rockets/Read the information on the International Space Station and rockets/Gather pictures of different types of rockets/Print/cut out/color&laminate rocket drawings/Find objects in the room to put in order by height. ☼ Oil Spot Photometer - Measure the brightness of the sun using cooking oil and a white card. A smear of oil on a white card becomes a powerful tool for comparing the brightness of two light sources, including the sun. ☼ The Sundial & Making Shadows-device to measure time by the

  4. Armenian Names of Sky Constellations

    Science.gov (United States)

    Mickaelian, A. M.; Farmanyan, S. V.; Mikayelyan, A. A.

    2016-12-01

    The work is devoted to the correction and recovery of the Armenian names of the sky constellations, as they were forgotten or distorted during the Soviet years, mainly due to the translation from Russian. A total of 34 constellation names have been corrected. A brief overview of the history of the division of the sky into constellations and their naming is also given. At the end, the list of all 88 constellations is given with the names in Latin, English, Russian and Armenian.

  5. Treasures of the Southern Sky

    CERN Document Server

    Gendler, Robert; Malin, David

    2011-01-01

    In these pages, the reader can follow the engaging saga of astronomical exploration in the southern hemisphere, in a modern merger of aesthetics, science, and a story of human endeavor. This book is truly a celebration of southern skies.  Jerry Bonnell, Editor - Astronomy Picture of the Day The southern sky became accessible to scientific scrutiny only a few centuries ago, after the first European explorers ventured south of the equator. Modern observing and imaging techniques have since revealed what seems like a new Universe, previously hidden below the horizon, a fresh astronomical bounty of beauty and knowledge uniquely different from the northern sky. The authors have crafted a book that brings this hidden Universe to all, regardless of location or latitude. Treasures of the Southern Sky celebrates the remarkable beauty and richness of the southern sky in words and with world-class imagery. In part, a photographic anthology of deep sky wonders south of the celestial equator, this book also celebrates th...

  6. A functional role of the sky's polarization pattern for orientation in the greater mouse-eared bat.

    Science.gov (United States)

    Greif, Stefan; Borissov, Ivailo; Yovel, Yossi; Holland, Richard A

    2014-07-22

    Animals can call on a multitude of sensory information to orient and navigate. One such cue is the pattern of polarized light in the sky, which for example can be used by birds as a geographical reference to calibrate other cues in the compass mechanism. Here we demonstrate that the female greater mouse-eared bat (Myotis myotis) uses polarization cues at sunset to calibrate a magnetic compass, which is subsequently used for orientation during a homing experiment. This renders bats the only mammal known so far to make use of the polarization pattern in the sky. Although there is currently no clear understanding of how this cue is perceived in this taxon, our observation has general implications for the sensory biology of mammalian vision.

  7. DNA binding studies of Sunset Yellow FCF using spectroscopy, viscometry and electrochemical techniques

    Science.gov (United States)

    Asaadi, Sara; Hajian, Reza

    2017-10-01

    Color is one of the important factors in food industry. All food companies use synthetic pigments to improve the aesthetic of products. Studies on the interaction between deoxyribonucleic acid (DNA) and food dye molecules is important because DNA is responsible for some processes including replication and transcription of cells, mutations, genetic diseases, and some synthetic chemical nucleases. In this study, the molecular interaction between Sunset Yellow FCF (SY) as a common food coloring additive and calf thymus DNA (ct-DNA) has been studied using UV-Vis spectrophotometry, spectrofluorometry, Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry and viscometry techniques. The binding constant between ct-DNA and SY in phosphate buffer solution (pH 7.4) was calculated as 2.09 × 103 L mol-1. The non-electrostatic bonding constant (K0t) was almost consistent and the ratio of K0t/Kb increased by increasing the ionic strength in the range of 0.01-0.1 mol L-1 of KCl. This observation shows that, the molecular bonding of SY to ct-DNA is a combination of electrostatic and intercalation interactions. In the electrochemical studies, an oxidation peak at 0.71 V and a reduction peak at about 0.63 V was observed with the peak potential difference (ΔEp) of 0.08 V, showing a reversible process. The oxidation and reduction peaks were significantly decreased in the presence of ct-DNA and the reduction peak current shifted to negative values. In spectrofluorometric study, the fluorescence intensity of SY increased dramatically after successive addition of DNA due to the increasing of molecular surface area and decreasing of impact frequency between solvent and SY-DNA adduct. Moreover, viscometric study shows that the increasing of viscosity for SY solution in the presence of DNA is due to the intercalation mechanism with double strand DNA (ds-DNA).

  8. 76 FR 76147 - Final Results of Expedited Sunset Review of Countervailing Duty Order: Certain Lined Paper...

    Science.gov (United States)

    2011-12-06

    ...: Certain Lined Paper Products From India AGENCY: Import Administration, International Trade Administration... sunset review of the countervailing duty (CVD) order on certain lined paper products (CLPP) from India... participate on behalf of the Association of American School Paper Suppliers (AASPS) and its individual members...

  9. 77 FR 38463 - Implementation of National Organic Program (NOP); Sunset Review (2012) Amendments to Pectin on...

    Science.gov (United States)

    2012-06-28

    ...: The Organic Foods Production Act of 1990 (OFPA) (7 U.S.C. 6501-6522) authorizes the establishment of... / Thursday, June 28, 2012 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 205 Implementation of National Organic Program (NOP); Sunset Review (2012)...

  10. 76 FR 78888 - Final Results of Expedited Sunset Review: Ferrovanadium and Nitrided Vanadium From Russia

    Science.gov (United States)

    2011-12-20

    ... Initiation of Five-Year (``Sunset'') Review, 76 FR 54430 (September 1, 2011). The Department received notices... From Russia AGENCY: Import Administration, International Trade Administration, Department of Commerce... (Russia), pursuant to section 751(c) of the Tariff Act of 1930, as amended (the Act). The Department...

  11. DISTINCTION OF MECHANICALLY PROCESSED WOOD SURFACES WITH SIMILAR QUALITIES USING SUNSET LASER TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Anna Carolina de Almeida Andrade

    2016-06-01

    Full Text Available The ASTM D 1666-11 (2011 norm classifies the quality of wood surface pieces after its mechanical processing. Although this classification is difficult to achieve visually, the use of some tools, such as solid state laser, can facilitate this classification. The aim of this work was to evaluate the use of sunset laser to qualify mechanically processed surfaces with similar visual qualities. We used a log from the base of a Khaya ivorensis tree and one from a K. senegalensis tree, both 11 years old. 22 specimens of dimensions 600x140x30 mm (CxLxE were made of each species. The specimens were flattened with speeds of 2400, 3600 and 4000 min-1 and advanced speeds were predetermined in 6 and 15 m.min-1. Then the samples were illuminated with sunset laser and photographed at high resolution, the images were transferred to the software Image J. To evaluate the sunset laser, areas of defects in wood that are classified as regular and bad by ASTM D 1666-11 (2011 were used. There was a difference in classification of wood defects between the two methods used, from the 31 specimens classified as regularly by visual analysis, 8 of them were classified as bad by the laser method. The use of solid-state laser in the sunset laser technique was more efficient in evaluating small differences in mechanically processed wood defects compared to visual evaluation.

  12. Hibiscus plant named `Sahara Sunset` U.S. Plant Patent 21,765

    Science.gov (United States)

    'Sahara Sunset' is a new and distinct cultivar of Hibiscus, botanically known as Hibiscus acetosella. The new Hibiscus was originated in Poplarville, Miss. and is a product of a mutation induction program. The parent of the present new cultivar is an unknown Hibiscus acetosella Wels. Ex Hiern seedli...

  13. 75 FR 51981 - Polychloroprene Rubber from Japan: Final Results of Sunset Review and Revocation of Finding

    Science.gov (United States)

    2010-08-24

    ... International Trade Administration Polychloroprene Rubber from Japan: Final Results of Sunset Review and... review of the antidumping finding on polychloroprene rubber from Japan. Because the domestic interested... polychloroprene rubber from Japan. See Polychloroprene Rubber from Japan, 38 FR 33593 (December 6, 1973)....

  14. The Boundary Layer Late Afternoon and Sunset Turbulence 2011 field experiment

    NARCIS (Netherlands)

    Lothon, M.; Lohou, F.; Durand, P.; Couvreux, F.; Hartogensis, O.K.; Legain, D.; Pardyjak, E.; Pino, D.; Vilà-Guerau de Arellano, J.; Boer, van de A.; Moene, A.F.; Steeneveld, G.J.

    2012-01-01

    BLLAST (Boundary Layer Late Afternoon and Sunset Turbulence) aims at better understanding the thermodynamical processes that occur during the late afternoon in the lower troposphere. In direct contact with the Earth surface, the atmospheric boundary layer is governed by buoyant and mechanical turbul

  15. 75 FR 54596 - Final Results of Expedited Sunset Review: Heavy Iron Construction Castings from Brazil

    Science.gov (United States)

    2010-09-08

    ... International Trade Administration Final Results of Expedited Sunset Review: Heavy Iron Construction Castings... of the countervailing duty order (``CVD'') on heavy iron construction castings from Brazil pursuant... review of the CVD order on iron construction castings from Brazil pursuant to section 751(c) of the...

  16. Dark Sky Protection and Education - Izera Dark Sky Park

    Science.gov (United States)

    Berlicki, Arkadiusz; Kolomanski, Sylwester; Mrozek, Tomasz; Zakowicz, Grzegorz

    2015-08-01

    Darkness of the night sky is a natural component of our environment and should be protected against negative effects of human activities. The night darkness is necessary for balanced life of plants, animals and people. Unfortunately, development of human civilization and technology has led to the substantial increase of the night-sky brightness and to situation where nights are no more dark in many areas of the World. This phenomenon is called "light pollution" and it can be rank among such problems as chemical pollution of air, water and soil. Besides the environment, the light pollution can also affect e.g. the scientific activities of astronomers - many observatories built in the past began to be located within the glow of city lights making the night observations difficult, or even impossible.In order to protect the natural darkness of nights many so-called "dark sky parks" were established, where the darkness is preserved, similar to typical nature reserves. The role of these parks is not only conservation but also education, supporting to make society aware of how serious the problem of the light pollution is.History of the dark sky areas in Europe began on November 4, 2009 in Jizerka - a small village situated in the Izera Mountains, when Izera Dark Sky Park (IDSP) was established - it was the first transboundary dark sky park in the World. The idea of establishing that dark sky park in the Izera Mountains originated from a need to give to the society in Poland and Czech Republic the knowledge about the light pollution. Izera Dark Sky Park is a part of the astro-tourism project "Astro Izery" that combines tourist attraction of Izera Valley and astronomical education under the wonderful starry Izera sky. Besides the IDSP, the project Astro Izery consists of the set of simple astronomical instruments (gnomon, sundial), natural educational trail "Solar System Model", and astronomical events for the public. In addition, twice a year we organize a 3-4 days

  17. Infrared Sky Imager (IRSI) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Victor R [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    The Infrared Sky Imager (IRSI) deployed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility is a Solmirus Corp. All Sky Infrared Visible Analyzer. The IRSI is an automatic, continuously operating, digital imaging and software system designed to capture hemispheric sky images and provide time series retrievals of fractional sky cover during both the day and night. The instrument provides diurnal, radiometrically calibrated sky imagery in the mid-infrared atmospheric window and imagery in the visible wavelengths for cloud retrievals during daylight hours. The software automatically identifies cloudy and clear regions at user-defined intervals and calculates fractional sky cover, providing a real-time display of sky conditions.

  18. Use of retailer fidelity card schemes in the assessment of food additive intake: Sunset Yellow a case study.

    Science.gov (United States)

    Sardi, M; Haldemann, Y; Nordmann, H; Bottex, B; Safford, B; Smith, B; Tennant, D; Howlett, J; Jasti, P R

    2010-11-01

    The feasibility of using a retailer fidelity card scheme to estimate food additive intake was investigated using the Swiss retailer MIGROS's Cumulus Card and the example of the food colour Sunset Yellow (E 110). Information held within the card scheme was used to identify a sample of households purchasing foods containing Sunset Yellow over a 15 day period. A sample of 1204 households was selected for interview, of which 830 households were retained in the study following interview. Interviews were conducted to establish household structure, patterns of consumption by different individuals within the household, and the proportion of foods containing Sunset Yellow habitually purchased at the retailer and/or consumed outside the home. Information provided by the retailer on levels of Sunset Yellow in the foods was combined with the information obtained at interview to calculate the per-capita intake of Sunset Yellow by members of participating households. More than 99% of consumers (n = 1902) of foods containing Sunset Yellow were estimated to consume less than 1 mg Sunset Yellow kg(-1) body weight day(-1). The method proved to be a simple and resource-efficient approach to estimate food additive intake on the basis of actual consumer behaviour and thus reports results more closely related to the actual consumption of foods by individuals.

  19. Teaching Chemistry Using October Sky

    Science.gov (United States)

    Goll, James G.; Wilkinson, Lindsay J.; Snell, Dolores M.

    2009-02-01

    The first artificial satellite, Sputnik, was launched over fifty years ago, on October 4, 1957, marking the beginning of the space age. The launch of Sputnik inspired coal miners’ sons in Coalwood, West Virginia, to form a rocket research program. The story of these coal miners’ sons was told by Homer Hickham, Jr., in the book Rocket Boys: A Memoir, and later in the movie adaptation October Sky. Both the book and the movie show the importance of mentoring from a teacher, Frieda Riley, who encouraged the Rocket Boys in their endeavors. The story of the Rocket Boys can be used in science classrooms as a means to teach the scientific process and to create what is termed in both the book and movie as a body of knowledge. Several chemical principles important in the development of rocket propellant systems were depicted in the book and movie. These propellant systems are comparable to those used for the solid rocket boosters used to launch the space shuttles. The use of popular media in the classroom can engage and inspire students and teachers alike.

  20. Exmoor - Europe's first International Dark Sky Reserve

    Science.gov (United States)

    Owens, S.

    2011-12-01

    On 2011 October 9 Exmoor National Park in the southwest of England was designated as Europe's first International Dark Sky Reserve by the International Dark Skies Association. This is a huge achievement, and follows three years of work by park authorities, local astronomers, lighting engineers and the resident community. Exmoor Dark Sky Reserve follows in the footsteps of Galloway Forest Dark Sky Park, set up in 2009, and Sark Dark Sky Island, established in January 2011.

  1. Exploring the Variable Sky with the Sloan Digital Sky Survey

    Science.gov (United States)

    2007-12-01

    0015, Japan. 8 Department of Astronomy,Graduate School of Science,University of Tokyo, 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033, Japan. 9 Institute...Survey (Pojmański 2002) mon- itors the entire southern and part of the northern sky ( < 25) to a limit of V ¼ 15. 5. OGLE (OGLE II; Udalski et al...lists photometric data for 215 million unique objects observed in 8000deg2 of sky as part of the ‘‘SDSS-I’’ phase that ran through 2005 June

  2. Hong Kong CIE sky classification and prediction by accessible weather data and trees-based methods

    Science.gov (United States)

    Lou, S.; Li, D. H. W.; Lam, J. C.

    2016-08-01

    Solar irradiance and daylight illuminance are important for solar energy and daylighting designs. Recently, the International Commission of Illuminance (CIE) adopted a range of sky conditions to represent the possible sky distributions which are crucial to the estimation of solar irradiance and daylight illuminance on vertical building facades. The important issue would be whether the sky conditions are correctly identified by the accessible variables. Previously, a number of climatic parameters including sky luminance distributions, vertical solar irradiance and sky illuminance were proposed for the CIE sky classification. However, such data are not always available. This paper proposes an approach based on the readily accessible data that systematically recorded by the local meteorological station for many years. The performance was evaluated using measured vertical solar irradiance and illuminance. The results show that the proposed approach is reliable for sky classification.

  3. Dark sky enters the lexicon

    Science.gov (United States)

    Showstack, Randy

    2012-01-01

    “Basketbrawl,” “cloud music,” “humblebrag,” and “occupy Wall Street.” These are some of the catchwords and phrases that lexicographer Grant Barrett included in a year-end newspaper column, “Which words will live on?,” in the New York Times on 31 December 2011. Among the couple dozen examples of new language was “dark sky.” Barrett wrote that it “designates a place free of nighttime light pollution. For example, the island of Sark in the English Channel is a dark-sky island.”

  4. 77 FR 73021 - Lemon Juice From Argentina: Final Results of the Expedited First Sunset Review of the Suspended...

    Science.gov (United States)

    2012-12-07

    ...'Alauro, Office of Policy, Bilateral Agreements Unit, Import Administration, International Trade... International Trade Administration Lemon Juice From Argentina: Final Results of the Expedited First Sunset Review of the Suspended Antidumping Duty Investigation AGENCY: Import Administration, International Trade...

  5. What's Up in the Atmosphere? Exploring How Aerosols Impact Sky Color Through Hands-on Activities with Elementary GLOBE

    Science.gov (United States)

    Damadeo, K.; Taylor, J.

    2015-12-01

    What color is the sky today? The GLOBE Kids - Anita, Simon, and Dennis want to know why the sky isn't always the same shade of blue and sometimes isn't even blue. Through the new Elementary GLOBE Aerosols Storybook and Learning Activities, the GLOBE Kids learn that there's a lot more than air in the atmosphere, which can affect the colors we see in the sky. There are four hands-on activities in this unit: 1) Sky Observers - Students make observations of the sky, record their findings and share their observation reports with their peers. The activity promotes active observation and recording skills to help students observe sky color, and recognize that sky color changes; 2) Why (Not) So Blue? - Students make predictions about how drops of milk will affect color and visibility in cups of water representing the atmosphere to help them understand that aerosols in the atmosphere have an effect on sky conditions, including sky color and visibility. The activity also introduces the classification categories for daytime sky color and visibility; 3) See the Light - Students use prisms and glue sticks to explore the properties of light. The activity demonstrates that white light is made up of seven colors that represent different wavelengths, and illustrates why the sky is blue during the day and red at sunset; 4) Up in the Air - Students work in groups to make an aerosol sampler, a simple adhesive tool that allows students to collect data and estimate the extent of aerosols present at their school, understanding that, in fact, there are particles in the air we breathe. NGSS Alignment includes: Disciplinary Core Ideas- ESS2.D: Weather and Climate, ESS3.C: Human Impacts on Earth Systems, PS4.B: Electromagnetic Radiation, ESS3.A: Natural Resources; Science and Engineering Practices- Asking Questions and Defining Problems, Planning and Carrying Out an Investigation, Analyzing and Interpreting Data, Engaging in Argument from Evidence, Obtaining, Evaluating, and Communicating

  6. Sky Observations by the Book

    Science.gov (United States)

    Trundle, Kathy Cabe; Sackes, Mesut

    2008-01-01

    The "National Science Education Standards (NSES)" state that students in grades K-4 are expected to understand that astronomical objects in the sky, including the Sun, Moon, and stars--have properties, locations, and patterns of movement that can be observed and described. They further suggest using an inquiry-based approach to teach…

  7. Deep-Sky Video Astronomy

    CERN Document Server

    Massey, Steve

    2009-01-01

    A guide to using modern integrating video cameras for deep-sky viewing and imaging with the kinds of modest telescopes available commercially to amateur astronomers. It includes an introduction and a brief history of the technology and camera types. It examines the pros and cons of this unrefrigerated yet highly efficient technology

  8. Uncertainties of parameterized surface downward clear-sky shortwave and all-sky longwave radiation.

    Directory of Open Access Journals (Sweden)

    S. Gubler

    2012-06-01

    Full Text Available As many environmental models rely on simulating the energy balance at the Earth's surface based on parameterized radiative fluxes, knowledge of the inherent model uncertainties is important. In this study we evaluate one parameterization of clear-sky direct, diffuse and global shortwave downward radiation (SDR and diverse parameterizations of clear-sky and all-sky longwave downward radiation (LDR. In a first step, SDR is estimated based on measured input variables and estimated atmospheric parameters for hourly time steps during the years 1996 to 2008. Model behaviour is validated using the high quality measurements of six Alpine Surface Radiation Budget (ASRB stations in Switzerland covering different elevations, and measurements of the Swiss Alpine Climate Radiation Monitoring network (SACRaM in Payerne. In a next step, twelve clear-sky LDR parameterizations are calibrated using the ASRB measurements. One of the best performing parameterizations is elected to estimate all-sky LDR, where cloud transmissivity is estimated using measured and modeled global SDR during daytime. In a last step, the performance of several interpolation methods is evaluated to determine the cloud transmissivity in the night.

    We show that clear-sky direct, diffuse and global SDR is adequately represented by the model when using measurements of the atmospheric parameters precipitable water and aerosol content at Payerne. If the atmospheric parameters are estimated and used as a fix value, the relative mean bias deviance (MBD and the relative root mean squared deviance (RMSD of the clear-sky global SDR scatter between between −2 and 5%, and 7 and 13% within the six locations. The small errors in clear-sky global SDR can be attributed to compensating effects of modeled direct and diffuse SDR since an overestimation of aerosol content in the atmosphere results in underestimating the direct, but overestimating the diffuse SDR. Calibration of LDR parameterizations

  9. The effect of Urban Park Sunset Program on land value in Korea

    Science.gov (United States)

    Kim, H. R.; Yoon, H.

    2016-12-01

    Intense urbanization has increased land scarcity in cities in the world, and consequently, securing lands for public parks and open spaces has become more challenging. Korea is not an exception. With Urban Park Sunset Plan, a plan for cancelling the designation as urban parks, nearly 583㎢ of publicly appropriated private land for the purpose will be released and returned to private owners. If municipalities want to keep the easement on the land, first, they should prepare physical design for parks or open spaces by 2015, and second, they should complete construction of those by 2020. In this study, we investigate the effect of Urban Park Sunset Program on land value. Our two-fold analysis includes: First, trend analysis where we extract variations of land values in Korea for 20 years (1996 2015). Second, we use panel data modeling to estimate the impact size of milestone plan implementation on land value; in 2000, Urban Park Sunset Plan was announced publicly, in 2015, the reserved land without physical design plan were released and finally, in 2020 the rest of the reserved land that has not yet been developed as parks or open spaces will be released. Along this process, we assess the ripple effect induced from the policy. As a result, we expect to find out potential economic impact of Urban Park Sunset Plan on land value, which could be applied for the preparation of countermeasures and the political decision making happening in the near future. This work was supported by the Korea Environmental Industry and Technology Institute (KEITI) under Grant (No. 2014-001-310007).

  10. Sunrise and Sunset Azimuths in the Planning of Ancient Chinese Towns

    OpenAIRE

    Sparavigna, Amelia Carolina

    2013-01-01

    Abstract: In the planning of some Chinese towns we can see an evident orientation with the cardinal direction north-south. However, other features reveal a possible orientation with the directions of sunrise and sunset on solstices too, as in the case of Shangdu (Xanadu), the summer capital of Kublai Khan. Here we discuss some other examples of a possible solar orientation in the planning of ancient towns. We will analyse the plans of Xi'an, Khanbalik and Dali

  11. A possible role of sunrise/sunset azimuth in the planning of ancient Chinese towns

    CERN Document Server

    Sparavigna, Amelia Carolina

    2013-01-01

    In the planning of some Chinese towns we can see an evident orientation with the cardinal north-south direction. However, other features reveal a possible orientation with the sunrise/sunset azimuth on solstices too, as in the case of Shangdu (Xanadu), the summer capital of Kublai Khan. Here we discuss some other examples of a possible solar orientation in the planning of ancient towns. We will analyze the plans of Xi'an, Khanbalik and Dali.

  12. Structural determination of unknown subsidiary colors in food yellow no. 5 (Sunset yellow FCF).

    Science.gov (United States)

    Yamada, M; Nakamura, M; Yamada, T; Maitani, T; Goda, Y

    1996-08-01

    Major unknown subsidiary colors A (Sub A) and B (Sub B) in commercial Sunset Yellow FCF (Food Yellow No. 5 in Japan) have been isolated by preparative HPLC. Spectroscopic analyses of Sub A and Sub B revealed that their structures are trisodium salt of 6-hydroxy-7-(4-sulfophenyl)-5-(4-sulfophenylazo)-2-naphthale nesulfonic acid, and disodium salt of 3-hydroxy-4-(4-sulfophenylazo)-2-naphthalenesulfonic acid, respectively.

  13. The Variation of Oncidium Rosy Sunset Flower Volatiles with Daily Rhythm, Flowering Period, and Flower Parts

    Directory of Open Access Journals (Sweden)

    Yi-Tien Chiu

    2017-09-01

    Full Text Available Oncidium is an important ornamental crop worldwide, and in recent years, the characteristics of the flower aroma have become a concern for breeders. This study used headspace solid-phase microextraction (HS-SPME and gas chromatography/mass spectrometry (GC-MS analysis of the volatile compounds to study the aroma characteristics of Onc. Rosy Sunset. A total of 45 compounds were identified, with the major compound being linalool. Onc. Rosy Sunset had the highest odor concentration from 10:00 to 12:00 and lowest from 20:00 to 24:00. The inflorescence emitted the highest quantities of volatile compounds during stages 3–6, which then decreased with the aging of the flowers. In Onc. Rosy Sunset, the sepals and petals were the major parts for the floral fragrance emission, in which linalool content was the highest, whereas the lip and column had a different composition of major volatile compounds, of which benzaldehyde, β-myrcene, and β-caryophyllene dominated.

  14. Show Time

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> Story: Show Time!The whole class presents the story"Under the Sea".Everyone is so excited and happy.Both Leo and Kathy show their parentsthe characters of the play."Who’s he?"asks Kathy’s mom."He’s the prince."Kathy replies."Who’s she?"asks Leo’s dad."She’s the queen."Leo replieswith a smile.

  15. Snobbish Show

    Institute of Scientific and Technical Information of China (English)

    YIN PUMIN

    2010-01-01

    @@ The State Administration of Radio,Film and Television (SARFT),China's media watchdog,issued a new set of mles on June 9 that strictly regulate TV match-making shows,which have been sweeping the country's primetime programming. "Improper social and love values such as money worship should not be presented in these shows.Humiliation,verbal attacks and sex-implied vulgar content are not allowed" the new roles said.

  16. Colors of the daytime overcast sky

    Science.gov (United States)

    Lee, Raymond L., Jr.; Hernández-Andrés, Javier

    2005-09-01

    Time-series measurements of daylight (skylight plus direct sunlight) spectra beneath overcast skies reveal an unexpectedly wide gamut of pastel colors. Analyses of these spectra indicate that at visible wavelengths, overcasts are far from spectrally neutral transmitters of the daylight incident on their tops. Colorimetric analyses show that overcasts make daylight bluer and that the amount of bluing increases with cloud optical depth. Simulations using the radiative-transfer model MODTRAN4 help explain the observed bluing: multiple scattering within optically thick clouds greatly enhances spectrally selective absorption by water droplets. However, other factors affecting overcast colors seen from below range from minimal (cloud-top heights) to moot (surface colors).

  17. On-sky tests of sky-subtraction methods for fiber-fed spectrographs

    CERN Document Server

    Rodrigues, Myriam; Hammer, Francois; Royer, Frederic; Evans, C J; Puech, Mathieu; Flores, Hector; Guinouard, Isabelle; Causi, Gianluca Li; Disseau, Karen; Yang, Yanbin

    2016-01-01

    We present preliminary results on on-sky test of sky subtraction methods for fiber-fed spectrograph. Using dedicated observation with FLAMES/VLT in I-band, we have tested the accuracy of the sky subtraction for 4 sky subtraction methods: mean sky, closest sky, dual stare and cross-beam switching. The cross beam-switching and dual stare method reach accuracy and precision of the sky subtraction under 1%. In contrast to the commonly held view in the literature, this result points out that fiber-fed spectrographs are adapted for the observations of faint targets.

  18. EROBATIC SHOW

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Visitors look at plane models of the Commercial Aircraft Corp. of China, developer of the count,s first homegrown large passenger jet C919, during the Singapore Airshow on February 16. The biennial event is the largest airshow in Asia and one of the most important aviation and defense shows worldwide. A number of Chinese companies took part in the event during which Okay Airways, the first privately owned aidine in China, signed a deal to acquire 12 Boeing 737 jets.

  19. Validation of spectral sky radiance derived from all-sky camera images – a case study

    Directory of Open Access Journals (Sweden)

    K. Tohsing

    2014-01-01

    Full Text Available Spectral sky radiance (380–760 nm is derived from measurements with a Hemispherical Sky Imager (HSI system. The HSI consists of a commercial compact CCD (charge coupled device camera equipped with a fish-eye lens and provides hemispherical sky images in three reference bands such as red, green and blue. To obtain the spectral sky radiance from these images non-linear regression functions for various sky conditions have been derived. The camera-based spectral sky radiance was validated by spectral sky radiance measured with a CCD spectroradiometer. The spectral sky radiance for complete distribution over the hemisphere between both instruments deviates by less than 20% at 500 nm for all sky conditions and for zenith angles less than 80°. The reconstructed spectra of the wavelength 380 nm to 760 nm between both instruments at various directions deviate by less then 20% for all sky conditions.

  20. Validation of spectral sky radiance derived from all-sky camera images – a case study

    Directory of Open Access Journals (Sweden)

    K. Tohsing

    2014-07-01

    Full Text Available Spectral sky radiance (380–760 nm is derived from measurements with a hemispherical sky imager (HSI system. The HSI consists of a commercial compact CCD (charge coupled device camera equipped with a fish-eye lens and provides hemispherical sky images in three reference bands such as red, green and blue. To obtain the spectral sky radiance from these images, non-linear regression functions for various sky conditions have been derived. The camera-based spectral sky radiance was validated using spectral sky radiance measured with a CCD spectroradiometer. The spectral sky radiance for complete distribution over the hemisphere between both instruments deviates by less than 20% at 500 nm for all sky conditions and for zenith angles less than 80°. The reconstructed spectra of the wavelengths 380–760 nm between both instruments at various directions deviate by less than 20% for all sky conditions.

  1. Monitoring Variability of the Sky

    CERN Document Server

    Paczynski, B

    2001-01-01

    Variability in the sky has been known for centuries, even millennia, but our knowledge of it is very incomplete even at the bright end. Current technology makes it possible to built small, robotic optical instruments, to record images and to process data in real time, and to archive them on-line, all at a low cost. In addition to obtaining complete catalogs of all kinds of variable objects, spectacular discoveries can be made, like the optical flash associated with GRB 990123 and a planetary transit in front of HD 209458. While prototypes of such robotic instruments have been in operation for several years, it is not possible to purchase a complete system at this time. I expect (hope) that complete systems will become available `off the shelf' in the near future, as monitoring bright sky for variability has a great scientific, educational and public outreach potential.

  2. The Alphabet and the Sky

    Science.gov (United States)

    Lebeuf, A.

    2011-06-01

    Since the beginning of the 17th century the letters of the Greek alphabet are used to identify the stars of constellation by order of magnitude. This was simply a practical means of astronomical classification. In several instances the Bible uses such metaphors as "The sky rolled up like a scroll". The idea of associating letters of different alphabets with stars, constellations and the sky in general can be found to day in the marginal subculture. The persistence of such an association of writing with astronomy or cosmology is at least of interest for cultural reasons, but the problem might be of good interest as well for the history of astronomy and cosmology. I present here two examples of this tradition in works of art. The first a painted representation of the Revelation of Saint John in the Orthodox church tradition, and the other in the construction of the late bronze age sacred well at Santa Cristina in Sardinia, Italy.

  3. Echoes in the sky

    CERN Multimedia

    2004-01-01

    A close-up of the ALEPH Time Projection Chamber (TPC) after the detector was dismantled, with a slice removed for the exhibition at the Musée International d'Horlogerie. People have long used clocks to keep time day to day. But only recently have scientists been able to pin down cosmic time, using the microwave background radiation to find the age of the universe. And to uncover what the cosmos was like back then, high-energy physics done at laboratories like CERN has been essential. On the occasion of CERN's 50th anniversary, starting 2 December at the Musée International d'Horlogerie in La Chaux-de-Fonds, Switzerland, a new exhibition will pay tribute to physics, from the cosmic to the subatomic scales. The exhibition, which run for several years, includes a slice of the Time Projection Chamber (TPC) from ALEPH, one of the LEP detectors, which CERN donated to the museum when the detector was dismantled. The show will also feature a cloud chamber used to detect particles, a video explaining what a particl...

  4. Superradiance in the sky

    Science.gov (United States)

    Rosa, João G.

    2017-03-01

    We discuss the conditions under which plane electromagnetic and gravitational waves can be amplified by a rotating black hole due to superradiant scattering. We show, in particular, that amplification can occur for low-frequency waves with an incidence angle parametrically close to 0 (or π ) with respect to the black hole spin axis and with a parametrically small left (or right) polarization. This is the case of the radiation emitted by a spinning electric/magnetic dipole or gravitational quadrupole orbiting a black hole companion at large radius and corotating with the latter. This can yield observable effects of superradiance, for example, in neutron star-stellar mass black hole binaries, as well as in triple systems composed by a compact binary orbiting a central supermassive black hole. Due to superradiance, the total source luminosity in these systems exhibits a characteristic orbital modulation that may lead to significant observational signatures, thus paving the way for testing, in the near future, one of the most peculiar predictions of general relativity.

  5. Hysteresis in the Sky

    Science.gov (United States)

    Choudhury, Sayantan; Banerjee, Shreya

    2016-07-01

    Hysteresis is a phenomenon occurring naturally in several magnetic and electric materials in condensed matter physics. When applied to cosmology, aka cosmological hysteresis, has interesting and vivid implications in the scenario of a cyclic bouncy universe. Most importantly, this physical prescription can be treated as an alternative proposal to inflationary paradigm. Cosmological hysteresis is caused by the asymmetry in the equation of state parameter during expansion and contraction phase of the universe, due to the presence of a single scalar field. This process is purely thermodynamical in nature, results in a non-vanishing hysteresis loop integral (∮pdV) in cosmology. When applied to variants of modified gravity models 1) Dvali-Gabadadze-Porrati (DGP) brane world gravity, 2) Cosmological constant dominated Einstein gravity, 3) Loop Quantum Gravity (LQG), 4) Einstein-Gauss-Bonnet brane world gravity and 5) Randall Sundrum single brane world gravity (RSII), under certain circumstances, this phenomenon leads to the increase in amplitude of the consecutive cycles and to a universe with older and larger successive cycles, provided we have physical mechanisms to make the universe bounce and turnaround. This inculcates an arrow of time in a dissipationless cosmology. Remarkably, this phenomenon appears to be widespread in several cosmological potentials in variants of modified gravity background, which we explicitly study for i) Hilltop, ii) Natural and iii) Coleman-Weinberg potentials, in this paper. Semi-analytical analysis of these models, for different potentials with minimum/minima, show that the conditions which creates a universe with an ever increasing expansion, depend on the signature of the hysteresis loop integral (∮pdV) as well as on the variants of model parameters.

  6. Sun, Earth and Sky

    Science.gov (United States)

    Lang, Kenneth R.

    1995-01-01

    The Sun is enveloped by a hot, tenuous million-degree corona that expands to create a continuous solar wind that sweeps past all the planets and fills the heliosphere. The solar wind is modulated by strong gusts that are initiated by powerful explosions on the Sun, including solar flares and coronal mass ejections. This dynamic, invisible outer atmosphere of the Sun is currently under observation with the soft X-ray telescope aboard the Yohkoh spacecraft, whose results are presented. We also show observations from the Ulysses spacecraft that is now passing over the solar pole, sampling the solar wind in this region for the first time. Two other spacecraft, Voyager 1 and 2, have recently detected the outer edge of the invisible heliosphere, roughly halfway to the nearest star. Magnetic solar activity, the total radiative output from the Sun, and the Earth's mean global surface temperature all vary with the 11-year sunspot cycle in which the total number of sunspots varies from a maximum to a minimum and back to a maximum again in about 11 years. The terrestrial magnetic field hollows out a protective magnetic cavity, called the magnetosphere, within the solar wind. This protection is incomplete, however, so the Sun feeds an unseen world of high-speed particles and magnetic fields that encircle the Earth in space. These particles endanger spacecraft and astronauts, and also produce terrestrial aurorae. An international flotilla of spacecraft is now sampling the weak points in this magnetic defense. Similar spacecraft have also discovered a new radiation belt, in addition to the familiar Van Allen belts, except fed by interstellar ions instead of electrons and protons from the Sun.

  7. Hemispherical sky simulator for daylighting model studies

    Energy Technology Data Exchange (ETDEWEB)

    Selkowitz, S.

    1981-07-01

    The design of a 24-foot-diameter hemispherical sky simulator recently completed at LBL is described. The goal was to produce a facility in which large models could be tested; which was suitable for research, teaching, and design; which could provide a uniform sky, an overcast sky, and several clear-sky luminance distributions, as well as accommodating an artificial sun. Initial operating experience with the facility is described, the sky simulator capabilities are reviewed, and its strengths and weaknesses relative to outdoor modeling tests are discussed.

  8. Mira Soars Through the Sky

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2 New ultraviolet images from NASA's Galaxy Evolution Explorer shows a speeding star that is leaving an enormous trail of 'seeds' for new solar systems. The star, named Mira (pronounced my-rah) after the latin word for 'wonderful,' is shedding material that will be recycled into new stars, planets and possibly even life as it hurls through our galaxy. In figure 1, the upper panel shows Mira's full, comet-like tail as seen only in shorter, or 'far' ultraviolet wavelengths, while the lower panel is a combined view showing both far and longer, or 'near' ultraviolet wavelengths. The close-up picture at bottom gives a better look at Mira itself, which appears as a pinkish dot, and is moving from left to right in this view. Shed material appears in light blue. The dots in the picture are stars and distant galaxies. The large blue dot on the left side of the upper panel, and the large yellow dot in the lower panel, are both stars that are closer to us than Mira. The Galaxy Evolution Explorer discovered the strange tail during part of its routine survey of the entire sky at ultraviolet wavelengths. When astronomers first saw the picture, they were shocked because Mira has been studied for over 400 years yet nothing like this has ever been documented before. Mira's comet-like tail stretches a startling 13 light-years across the sky. For comparison, the nearest star to our sun, Proxima Centauri, is only about 4 light-years away. Mira's tail also tells a tale of its history -- the material making it up has been slowly blown off over time, with the oldest material at the end of the tail being released about 30,000 years ago (figure 2). Mira is a highly evolved, 'red giant' star near the end of its life. Technically, it is called an asymptotic giant branch star. It is red in color and bloated; for example, if a red giant were to replace our sun, it would engulf

  9. All-Sky Interferometry with Spherical Harmonic Transit Telescopes

    CERN Document Server

    Shaw, J Richard; Pen, Ue-Li; Stebbins, Albert; Sitwell, Michael

    2014-01-01

    In this paper we describe the spherical harmonic transit telescope, a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved sky complications of traditional interferometry and so is particularly well suited to the analysis of wide-field radio interferometers. It enables compact and computationally efficient representations of the data and its statistics that allow new ways of approaching important problems like map-making and foreground removal. In particular, we show how it enables the use of the Karhunen-Loeve transform as a highly effective foreground filter, suppressing realistic foreground residuals for our fiducial example by at least a factor twenty below the 21cm signal even in highly contaminated regions of the sky. This is despite the presence of the angle-frequency mode mixing inherent in real-world instruments with frequency-dependent beams. We show, using Fisher forecasting, that foreground cleaning has little effect on power spectrum constraints ...

  10. TV shows on Light Pollution Education for the Public

    Science.gov (United States)

    Grigore, Valentin

    2015-03-01

    TV shows have the biggest impact for the public, so we can use them to inform and educate the public about light pollution and the importance of the dark sky for humanity and for the contemporary society. Some examples used in the TV show Us and the Sky at Columna TV, Romania, are presented.

  11. A method for selecting the CIE standard general sky model with regard to calculating luminance distributions

    Science.gov (United States)

    Ferraro, Vittorio; Marinelli, Valerio; Mele, Marilena

    2013-04-01

    It is known that the best predictions of sky luminances are obtainable by the CIE 15 standard skies model, but the predictions by this model need knowledge of the measured luminance distributions themselves, since a criterion for selecting the type of sky starting from the irradiance values has not found until now. The authors propose a new simple method of applying the CIE model, based on the use of the sky index Si. A comparison between calculated luminance data and data measured in Arcavacata of Rende (Italy), Lyon (France) and Pamplona (Spain) show a good performance of this method in comparison with other methods of calculation of luminance existing in the literature.

  12. Sky Variability in the y Band at the LSST Site

    CERN Document Server

    High, F William; Stalder, Brian; Gilmore, David Kirk; Tonry, John L

    2010-01-01

    We have measured spatial and temporal variability in the y band sky brightness over the course of four nights above Cerro Tololo near Cerro Pachon, Chile, the planned site for the Large Synoptic Survey Telescope (LSST). Our wide-angle camera lens provided a 41 deg field of view and a 145 arcsec pixel scale. We minimized potential system throughput differences by deploying a deep depletion CCD and a filter that matches the proposed LSST y_3 band (970 to 1030 nm). Images of the sky exhibited coherent wave structure, attributable to atmospheric gravity waves at 90 km altitude, creating 3 to 4% root mean square spatial sky flux variability on scales of about 2 degrees and larger. Over the course of a full night the y_3 band additionally showed highly coherent temporal variability of up to a factor of 2 in flux. We estimate the mean absolute sky level to be approximately y_3 = 17.8 mag (Vega), or y_3 = 18.3 mag (AB). While our observations were made through a y_3 filter, the relative sky brightness variability sho...

  13. Astronomical Sky Quality Near Eureka, in the Canadian High Arctic

    CERN Document Server

    Steinbring, Eric; Drummond, James R

    2011-01-01

    Nighttime visible-light sky brightness and transparency are reported for the Polar Environment Research Laboratory (PEARL), located on a 610-m high ridge near the Eureka research station, on Ellesmere Island, Canada. Photometry of Polaris obtained in V band with the PEARL All Sky Imager (PASI) over two winters is supported by standard meteorological measurements and visual estimates of sky conditions from sea level. These data show that during the period of the study, October through March of 2008/09 and 2009/10, the sky near zenith had a mean surface brightness of 19.7 mag/square-arcsec when the sun was more than 12 deg below the horizon, reaching 20.7 mag/square-arcsec during astronomical darkness with no moon. Skies were without thick cloud and potentially usable for astronomy 86% of the time (extinction <2 mag). Up to 68% of the time was spectroscopic (<0.5 mag), attenuated by ice crystals, or clear with stable atmospheric transparency. Those conditions can persist for over 100 hours at a time. Furt...

  14. Design of a Device for Sky Light Polarization Measurements

    Directory of Open Access Journals (Sweden)

    Yujie Wang

    2014-08-01

    Full Text Available ky polarization patterns can be used both as indicators of atmospheric turbidity and as a sun compass for navigation. The objective of this study is to improve the precision of sky light polarization measurements by optimal design of the device used. The central part of the system is composed of a Charge Coupled Device (CCD camera; a fish-eye lens and a linear polarizer. Algorithms for estimating parameters of the polarized light based on three images are derived and the optimal alignments of the polarizer are analyzed. The least-squares estimation is introduced for sky light polarization pattern measurement. The polarization patterns of sky light are obtained using the designed system and they follow almost the same patterns of the single-scattering Rayleigh model. Deviations of polarization angles between observation and the theory are analyzed. The largest deviations occur near the sun and anti-sun directions. Ninety percent of the deviations are less than 5° and 40% percent of them are less than 1°. The deviations decrease evidently as the degree of polarization increases. It also shows that the polarization pattern of the cloudy sky is almost identical as in the blue sky.

  15. SkyMine Carbon Mineralization Pilot Project

    Energy Technology Data Exchange (ETDEWEB)

    Christenson, Norm; Walters, Jerel

    2014-12-31

    This Topical Report addresses accomplishments achieved during Phase 2b of the SkyMine® Carbon Mineralization Pilot Project. The primary objectives of this project are to design, construct, and operate a system to capture CO2 from a slipstream of flue gas from a commercial coal-fired cement kiln, convert that CO2 to products having commercial value (i.e., beneficial use), show the economic viability of the CO2 capture and conversion process, and thereby advance the technology to the point of readiness for commercial scale demonstration and deployment. The overall process is carbon negative, resulting in mineralization of CO2 that would otherwise be released into the atmosphere. The project will also substantiate market opportunities for the technology by sales of chemicals into existing markets, and identify opportunities to improve technology performance and reduce costs at the commercial scale. The project is being conducted in two phases. The primary objectives of Phase 1 were to evaluate proven SkyMine® process chemistry for commercial pilot-scale operation and complete the preliminary design for the pilot plant to be built and operated in Phase 2, complete a NEPA evaluation, and develop a comprehensive carbon life cycle analysis. The objective of Phase 2b was to build the pilot plant to be operated and tested in Phase 2c.

  16. The Tomaraho Conception of the Sky

    CERN Document Server

    Sequera, Guillermo

    2011-01-01

    The small community of the Tomaraho, an ethnic group culturally derived from the Zamucos, became known in the South American and world anthropological scenario in recent times. This group, far from the banks of the Paraguay river, remained concealed from organized modern societies for many years. Like any other groups of people in close contact with nature, the Tomaraho developed a profound and rich world view which parallels other more widely researched aboriginal cultures as well as showing distinctive features of their own. This is also apparent in their imagery of the sky and of the characters that are closely connected with the celestial sphere. This paper is based on the lengthy anthropological studies of G. Sequera. We have recently undertaken a project to carry out a detailed analysis of the different astronomical elements present in the imagined sky of the Tomaraho and other Chamacoco ethnic groups. We will briefly review some aspects of this aboriginal culture: places where they live, regions of inf...

  17. SkyMine Carbon Mineralization Pilot Project

    Energy Technology Data Exchange (ETDEWEB)

    Joe Jones; Clive Barton; Mark Clayton; Al Yablonsky; David Legere

    2010-09-30

    This Topical Report addresses accomplishments achieved during Phase 1 of the SkyMine{reg_sign} Carbon Mineralization Pilot Project. The primary objectives of this project are to design, construct, and operate a system to capture CO{sub 2} from a slipstream of flue gas from a commercial coal-fired cement kiln, convert that CO{sub 2} to products having commercial value (i.e., beneficial use), show the economic viability of the CO{sub 2} capture and conversion process, and thereby advance the technology to a point of readiness for commercial scale demonstration and proliferation. The project will also substantiate market opportunities for the technology by sales of chemicals into existing markets, and identify opportunities to improve technology performance and reduce costs at commercial scale. The primary objectives of Phase 1 of the project were to elaborate proven SkyMine{reg_sign} process chemistry to commercial pilot-scale operation and complete the preliminary design ('Reference Plant Design') for the pilot plant to be built and operated in Phase 2. Additionally, during Phase 1, information necessary to inform a DOE determination regarding NEPA requirements for the project was developed, and a comprehensive carbon lifecycle analysis was completed. These items were included in the formal application for funding under Phase 2. All Phase 1 objectives were successfully met on schedule and within budget.

  18. [Studies on rejected food yellow no. 5 (sunset yellow FCF) aluminum lake].

    Science.gov (United States)

    Tsuji, S; Umino, Y; Nakamura, Y; Tonogai, Y

    2001-01-01

    One out of two sunset yellow FCF aluminum lakes (Y-5Als) did not comply with the specifications in JSFA-VII in the official inspection of tar colors in fiscal year 2000. A sub-spot was detected in the paper chromatography test. This rejected sample was analyzed by HPLC for the subsidiary color, raw materials and intermEdiates in Y-5. The sub-spot was identified as sulfanilic acid azo R salt color, and its content was estimated at 4.5% as the content of Y-5 in Y-5Al being 100.0%.

  19. [Analysis of tartrazine aluminum lake and sunset yellow aluminum lake in foods by capillary zone electrophoresis].

    Science.gov (United States)

    Zhang, Yiding; Chang, Cuilan; Guo, Qilei; Cao, Hong; Bai, Yu; Liu, Huwei

    2014-04-01

    A novel analytical method for tartrazine aluminum lake and sunset yellow aluminum lake using capillary zone electrophoresis (CZE) was studied. The pigments contained in the color lakes were successfully separated from the aluminum matrix in the pre-treatment process, which included the following steps: dissolve the color lakes in 0.1 mol/L H2SO4, adjust the pH of the solution to 5.0, then mix it with the solution of EDTA x 2Na and heat it in a water bath, then use polyamide powder as the stationary phase of solid phase extraction to separate the pigments from the solution, and finally elute the pigments with 0.1 mol/L NaOH. The CZE conditions systematically optimized for tartrazine aluminum lake were: 48.50 cm of a fused silica capillary with 40.00 cm effective length and 50 microm i. d., the temperature controlled at 20.0 degrees C, 29.0 kV applied, HPO4(2-)-PO4(3-) (0.015 mol/L, pH 11.45) solution as running buffer, detection at 263 nm. The conditions for sunset yellow aluminum lake were: the same capillary and temperature, 25.0 kV applied, HPO4(2-)-PO4(3-) (0.025 mol/L, pH 11.45) solution as running buffer, detection at 240 nm. The limits of detection were 0.26 mg/L and 0.27 mg/L, and the linear ranges were 0.53-1.3 x 10(2) mg/L and 0.54-1.4 x 10(2) mg/L for tartrazine aluminum lake and sunset yellow aluminum lake, respectively. The RSDs were 4.3% and 5.7% (run to run, n = 6), 5.6% and 6.0% (day to day, n = 6) for tartrazine aluminum lake and sunset yellow aluminum lake, respectively. Further developments for this method could make it a routinely used method analyzing color lakes in foods.

  20. ZAP -- Enhanced PCA Sky Subtraction for Integral Field Spectroscopy

    CERN Document Server

    Soto, Kurt T; Bacon, Roland; Richard, Johan; Conseil, Simon

    2016-01-01

    We introduce Zurich Atmosphere Purge (ZAP), an approach to sky subtraction based on principal component analysis (PCA) that we have developed for the Multi Unit Spectrographic Explorer (MUSE) integral field spectrograph. ZAP employs filtering and data segmentation to enhance the inherent capabilities of PCA for sky subtraction. Extensive testing shows that ZAP reduces sky emission residuals while robustly preserving the flux and line shapes of astronomical sources. The method works in a variety of observational situations from sparse fields with a low density of sources to filled fields in which the target source fills the field of view. With the inclusion of both of these situations the method is generally applicable to many different science cases and should also be useful for other instrumentation. ZAP is available for download at http://muse-vlt.eu/science/tools.

  1. Using inpainting to construct accurate cut-sky CMB estimators

    CERN Document Server

    Gruetjen, H F; Liguori, M; Shellard, E P S

    2015-01-01

    The direct evaluation of manifestly optimal, cut-sky CMB power spectrum and bispectrum estimators is numerically very costly, due to the presence of inverse-covariance filtering operations. This justifies the investigation of alternative approaches. In this work, we mostly focus on an inpainting algorithm that was introduced in recent CMB analyses to cure cut-sky suboptimalities of bispectrum estimators. First, we show that inpainting can equally be applied to the problem of unbiased estimation of power spectra. We then compare the performance of a novel inpainted CMB temperature power spectrum estimator to the popular apodised pseudo-$C_l$ (PCL) method and demonstrate, both numerically and with analytic arguments, that inpainted power spectrum estimates significantly outperform PCL estimates. Finally, we study the case of cut-sky bispectrum estimators, comparing the performance of three different approaches: inpainting, apodisation and a novel low-l leaning scheme. Providing an analytic argument why the loca...

  2. Mapping the nano-Hertz gravitational wave sky

    CERN Document Server

    Cornish, Neil J

    2014-01-01

    We describe a new method for extracting gravitational wave signals from pulsar timing data. We show that any gravitational wave signal can be decomposed into an orthogonal set of sky maps, with the number of maps equal to the number of pulsars in the timing array. These maps may be used as a basis to construct gravitational wave templates for any type of source, including collections of point sources. A variant of the standard Hellings-Downs correlation analysis is recovered for statistically isotropic signals. The template based approach allows us to probe potential anisotropies in the signal and produce maps of the gravitational wave sky.

  3. Improving night sky star image processing algorithm for star sensors.

    Science.gov (United States)

    Arbabmir, Mohammad Vali; Mohammadi, Seyyed Mohammad; Salahshour, Sadegh; Somayehee, Farshad

    2014-04-01

    In this paper, the night sky star image processing algorithm, consisting of image preprocessing, star pattern recognition, and centroiding steps, is improved. It is shown that the proposed noise reduction approach can preserve more necessary information than other frequently used approaches. It is also shown that the proposed thresholding method unlike commonly used techniques can properly perform image binarization, especially in images with uneven illumination. Moreover, the higher performance rate and lower average centroiding estimation error of near 0.045 for 400 simulated images compared to other algorithms show the high capability of the proposed night sky star image processing algorithm.

  4. MSDS sky reference and preamplifier study

    Science.gov (United States)

    Larsen, L.; Stewart, S.; Lambeck, P.

    1974-01-01

    The major goals in re-designing the Multispectral Scanner and Data System (MSDS) sky reference are: (1) to remove the sun-elevation angle and aircraft-attitude angle dependence from the solar-sky illumination measurement, and (2) to obtain data on the optical state of the atmosphere. The present sky reference is dependent on solar elevation and provides essentially no information on important atmospheric parameters. Two sky reference designs were tested. One system is built around a hyperbolic mirror and the reflection approach. A second approach to a sky reference utilizes a fish-eye lens to obtain a 180 deg field of view. A detailed re-design of the present sky reference around the fish-eye approach, even with its limitations, is recommended for the MSDS system. A preamplifier study was undertaken to find ways of improving the noise-equivalent reflectance by reducing the noise level for silicon detector channels on the MSDS.

  5. Genotoxic and cytotoxic effects of Sunset Yellow and Brilliant Blue, colorant food additives, on human blood lymphocytes.

    Science.gov (United States)

    Kus, Esra; Eroglu, Halil Erhan

    2015-01-01

    The synthetic dyes over fifty are used in many areas including the food industry around the world. Sunset Yellow FCF and Brilliant Blue FCF are used as colorant food additives in many food products. The present study investigated the genotoxic and cytotoxic effects of Sunset Yellow and Brilliant Blue. Genotoxic and cytotoxic activities of the food additives were evaluated in lymphocyte cell cultures using mitotic index, replication index and micronucleus assay. Mitotic index frequencies and replication index values were decreased and micronucleus frequency was increased with increasing concentrations of Sunset Yellow and Brilliant Blue. The changes in mitotic index and micronucleus are statistically significant (pBlue can have cytotoxic and genotoxic potential. It care must be taken when using these materials as a food additive.

  6. Nightscape Photography Reclaims the Natural Sky

    Science.gov (United States)

    Tafreshi, Babak

    2015-08-01

    Nightscape photos and timelapse videos, where the Earth & sky are framed together with an astronomical purpose, support the dark skies activities by improving public awareness. TWAN or The World at Night program (www.twanight.org) presents the world's best collection of such landscape astrophotos and aims to introduce the night sky as a part of nature, an essential element of our living environment besides being the astronomers lab. The nightscape images also present views of our civilizations landmarks, both natural and historic sites, against the night-time backdrop of stars, planets, and celestial events. In this context TWAN is a bridge between art, science and culture.TWAN images contribute to programs such as the Dark Sky Parks by the International Dark Sky Association or Starlight reserves by assisting local efforts in better illustrating their dark skies and by producing stunning images that not only educate the local people on their night sky heritage also communicate with the governments that are responsible to support the dark sky area.Since 2009 TWAN organizes the world's largest annual photo contest on nightscape imaging, in collaboration with the Dark Skies Awareness, National Optical Astronomy Observatory, and Astronomers Without Borders. The International Earth & Sky Photo Contest promotes the photography that documents the beauty of natural skies against the problem of light pollution. In 2014 the entries received from about 50 countries and the contest result news was widely published in the most popular sources internationally.*Babak A. Tafreshi is a photographer and science communicator. He is the creator of The World At Night program, and a contributing photographer to the National Geographic, Sky&Telescope magazine, and the European Southern Observatory. http://twanight.org/tafreshi

  7. Daytime Water Detection Based on Sky Reflections

    Science.gov (United States)

    Rankin, Arturo; Matthies, Larry; Bellutta, Paolo

    2011-01-01

    A water body s surface can be modeled as a horizontal mirror. Water detection based on sky reflections and color variation are complementary. A reflection coefficient model suggests sky reflections dominate the color of water at ranges > 12 meters. Water detection based on sky reflections: (1) geometrically locates the pixel in the sky that is reflecting on a candidate water pixel on the ground (2) predicts if the ground pixel is water based on color similarity and local terrain features. Water detection has been integrated on XUVs.

  8. Sky Radiometers on Stand for Downwelling Radiation

    Data.gov (United States)

    Oak Ridge National Laboratory — The Sky Radiation (SKYRAD) collection of radiometers provides each Atmospheric Radiation and Cloud Station (ARCS) with continuous measurements of broadband shortwave...

  9. Night sky a falcon field guide

    CERN Document Server

    Nigro, Nicholas

    2012-01-01

    Night Sky: A Falcon Field Guide covers both summer and winter constellations, planets, and stars found in the northern hemisphere. Conveniently sized to fit in a pocket and featuring detailed photographs, this informative guide makes it easy to identify objects in the night sky even from one's own backyard. From information on optimal weather conditions, preferred viewing locations, and how to use key tools of the trade, this handbook will help you adeptly navigate to and fro the vast and dynamic nighttime skies, and you'll fast recognize that the night sky's the limit.

  10. Characterization of clear sky conditions over El Leoncito Observatory from an all-sky imager designed for upper atmosphere studies.

    OpenAIRE

    Martinis, C.; Wilson, J.; Zablowski, P.; Baumgardner, J.; Aballay, Jose Luis; Garcia, Beatriz Elena; Ristori, Pablo Roberto; Otero, Lidia Ana

    2015-01-01

    A method for determining cloud cover fraction over El Leoncito Observatory (31.8°S, 69.3°W) is presented. Data from an all-sky imaging system, designed to measure nightglow originating from the mesosphere and thermosphere, is used to determine the fraction of the sky covered by clouds. More than 9,000 hr of observations from May 2006 to December 2010 are used to show that El Leoncito is clear approximately 75–80% of the time. No significant seasonal variations are observed. The optical ground...

  11. Online Ephemerides – the Equation of Time and True Solar Time, Sunrise and Sunset and the Corresponding Azimuths

    Directory of Open Access Journals (Sweden)

    Goran Tomac

    2015-12-01

    Full Text Available The paper describes the Croatian web page Online ephemerides with its applications for calculating and visualising the equation of time and the analemma, converting zone time (zone or civil time into true solar time (the time shown by sundials and calculating the time of sunrise and sunset and the corresponding azimuths. The calculated values for the equation of time, ephemeris transit and the true solar time of ±4 seconds, sunrise and sunset times of ±30 seconds and the azimuth of ±30” must meet the accuracy needed by both amateur and professional astronomers. The web applications described are also adapted for smart phones.

  12. Coloration using higher order optical interference in the wing pattern of the Madagascan sunset moth.

    Science.gov (United States)

    Yoshioka, S; Nakano, T; Nozue, Y; Kinoshita, S

    2008-04-06

    Colour patterns of animals' bodies are usually produced by the spatial distribution of pigments with different colours. However, some animals use the spatial variation of colour-producing microstructures. We have studied one distinctive example of such structurally produced colour patterns, the wing of the Madagascan sunset moth, to clarify the physical rules that underlie the colour variation. It is known that the iridescent wing scale of the sunset moth has the alternate air-cuticle multilayer structure that causes optical interference. The microscopic and optical investigations of various parts of the wing have confirmed that the thickness of the cuticle layers within the scale largely varies to produce the colour pattern. However, it varies in very different ways between the dorsal and ventral sides of the hind wing; the thickness gradually varies on the dorsal side from scale to scale, while the abrupt changes are found on the ventral side to form distinctive borders between differently coloured areas. It is also revealed that an unusual coloration mechanism is involved in the green part of the ventral hind wing: the colour is caused by higher order optical interference of the highly non-ideal multilayer structure. The physical mechanism of the colour pattern formation is briefly discussed with the several mathematical models proposed so far.

  13. The SDSS SkyServer Public Access to the Sloan Digital Sky Server Data

    CERN Document Server

    Szalay, A S; Thakar, A R; Kunszt, Zoltán; Malik, T; Raddick, J; Stoughton, C; Van den Berg, J

    2002-01-01

    The SkyServer provides Internet access to the public Sloan Digi-tal Sky Survey (SDSS) data for both astronomers and for science education. This paper describes the SkyServer goals and archi-tecture. It also describes our experience operating the SkyServer on the Internet. The SDSS data is public and well-documented so it makes a good test platform for research on database algorithms and performance.

  14. Sky Quality Meter measurements in a colour-changing world

    Science.gov (United States)

    Sánchez de Miguel, A.; Aubé, M.; Zamorano, J.; Kocifaj, M.; Roby, J.; Tapia, C.

    2017-05-01

    The Sky Quality Meter (SQM) has become the most common device used to track the evolution of the brightness of the sky from polluted regions to first-class astronomical observatories. A vast database of SQM measurements already exists for many places in the world. Unfortunately, the SQM operates over a wide spectral band and its spectral response interacts with the sky's spectrum in a complex manner. This is why the optical signals are difficult to interpret when the data are recorded in regions with different sources of artificial light. The brightness of the night sky is linked in a complex way to ground-based light emissions, while taking into account atmospheric-induced optical distortion as well as spectral transformation from the underlying ground surfaces. While the spectral modulation of the sky's radiance has been recognized, it still remains poorly characterized and quantified. The impact of the SQM's spectral characteristics on sky-brightness measurements is analysed here for different light sources, including low- and high-pressure sodium lamps, PC-amber and white LEDs, metal halide and mercury lamps. We show that a routine conversion of radiance to magnitude is difficult, or rather impossible, because the average wavelength depends on actual atmospheric and environment conditions, the spectrum of the source and device-specific properties. We correlate SQM readings with both the Johnson astronomical photometry bands and the human system of visual perception, assuming different lighting technologies. These findings have direct implications for the processing of SQM data and for their improvement and/or remediation.

  15. C-BASS: The C-Band All Sky Survey

    Science.gov (United States)

    Pearson, Timothy J.; C-BASS Collaboration

    2016-06-01

    The C-Band All Sky Survey (C-BASS) is a project to image the whole sky at a wavelength of 6 cm (frequency 5 GHz), measuring both the brightness and the polarization of the sky. Correlation polarimeters are mounted on two separate telescopes, one at the Owens Valley Observatory (OVRO) in California and another in South Africa, allowing C-BASS to map the whole sky. The OVRO instrument has completed observations for the northern part of the survey. We are working on final calibration of intensity and polarization. The southern instrument has recently started observations for the southern part of the survey from its site at Klerefontein near Carnarvon in South Africa. The principal aim of C-BASS is to allow the subtraction of polarized Galactic synchrotron emission from the data produced by CMB polarization experiments, such as WMAP, Planck, and dedicated B-mode polarization experiments. In addition it will contribute to studies of: (1) the local (region close to the Galactic plane. Observations at many wavelengths from radio to infrared are needed to fully understand the foregrounds. At 5 GHz, C-BASS maps synchrotron polarization with minimal corruption by Faraday rotation, and complements the full-sky maps from WMAP and Planck. I will present the project status, show results of component separation in selected sky regions, and describe the northern survey data products.C-BASS (http://www.astro.caltech.edu/cbass/) is a collaborative project between the Universities of Oxford and Manchester in the UK, the California Institute of Technology (supported by the National Science Foundation and NASA) in the USA, the Hartebeesthoek Radio Astronomy Observatory (supported by the Square Kilometre Array project) in South Africa, and the King Abdulaziz City for Science and Technology (KACST) in Saudi Arabia.

  16. Dark Skies Awareness Programs for the International Year of Astronomy

    Science.gov (United States)

    Walker, Constance E.; US IYA Dark Skies Working Group

    2009-05-01

    The arc of the Milky Way seen from a truly dark location is part of our planet's cultural and natural heritage. More than 1/5 of the world population, 2/3 of the United States population and 1/2 of the European Union population have already lost naked-eye visibility of the Milky Way. This loss, caused by light pollution, is a serious and growing issue that impacts astronomical research, the economy, ecology, energy conservation, human health, public safety and our shared ability to see the night sky. For this reason, "Dark Skies” is a cornerstone project of the International Year of Astronomy. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people worldwide involved in a variety of programs that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking on Facebook and MySpace, a Second Life presence) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Nights in the (National) Parks, Sidewalk Astronomy) 3) Organize events in the arts (e.g., a photography contest) 4) Involve citizen-scientists in naked-eye and digital-meter star hunting programs (e.g., GLOBE at Night, "How Many Stars?", the Great World Wide Star Count and the radio frequency interference equivalent: "Quiet Skies") and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security, and astronomy (e.g., The Starlight Initiative, World Night in Defense of Starlight, International Dark Sky Week, International Dark-Sky Communities, Earth Hour, The Great Switch Out, a traveling exhibit, downloadable posters and brochures). The poster will provide an update, describe how people can continue to participate, and take a look ahead at the program's sustainability. For more information, visit www.darkskiesawareness.org.

  17. The role of post-sunset vertical drifts at the equator in predicting the onset of VHF scintillations during high and low sunspot activity years

    Directory of Open Access Journals (Sweden)

    S. Tulasi Ram

    2006-07-01

    Full Text Available The day-to-day variability in the occurrence of ionospheric scintillations, which are of serious concern in the trans-ionospheric communications, makes their prediction still a challenging problem. This paper reports on a systematic study in quantitatively identifying the precursors responsible, such as pre-reversal E×B drift velocity, geo-magnetic activity index (Kp and the Equatorial Ionization Anomaly (EIA gradient, for the onset of VHF scintillations over a low-latitude station, Waltair (20° N dip, during high (2001 and low (2004 sunspot activity years. The percentage of occurrences of VHF scintillations over Waltair show a good correlation with the monthly mean post-sunset vertical drift velocities at the equator, during both the high and low sunspot activity years. During the days on which intense (>10 dB scintillations occur, the ionization anomaly gradient (dN/dL, measured from ionosonde data of an equatorial (Trivandrum, 0.9° N dip and an off-equatorial station (Waltair, 20° N dip shows an enhancement in the gradient prior to the onset of the scintillations. However, this enhancement is not seen on days when the scintillations are weak (<10 dB or absent. The day-to-day post sunset enhancement in the E×B drift is found to decrease with increasing Kp-index and this decrease is more prominent in the equinoxes, less in winter and insignificant in the summer months. On a day-to-day basis, it is found that the value of the upward drift velocity at the equator should be ≥30 m/s for the onset of strong scintillations over Waltair for magnetically quiet days with average Kp≤2 (6 h prior to the local sunset during the high sunspot year, 2001. This threshold value of the upward drift reduces to 20 m/s with the decrease in the sunspot activity during 2004. Further, these conditions for the onset of intense scintillations is well defined in equinoxes, less in

  18. Dark Skies, Bright Kids Year 8

    Science.gov (United States)

    Bittle, Lauren E.; Wenger, Trey; Johnson, Kelsey E.; Angell, Dylan; Burkhardt, Andrew; Davis, Blair; Firebaugh, Ariel; Hancock, Danielle; Richardson, Whitney; Rochford Hayes, Christian; Linden, Sean; Liss, Sandra; Matthews, Allison; McNair, Shunlante; Prager, Brian; Pryal, Matthew; Troup, Nicholas William

    2017-01-01

    We present activities from the eighth year of Dark Skies Bright Kids (DSBK), an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Central Virginia through fun, hands-on activities that introduce basic Astronomy concepts. Over the past seven years, our primary focus has been hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools, and over the past several years, we have partnered with local businesses to host our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows. This past summer we expanded our reach through a new initiative to bring week-long summer day camps to south and southwest Virginia, home to some of the most underserved communities in the commonwealth.

  19. Blue Skies Research and the global economy

    Science.gov (United States)

    Braben, Donald W.

    2002-11-01

    Robert Solow's seminal work of the 1950s showed that science and technology are major sources of long-term global economic growth. But we have recently changed the ways that science and technology are managed. Industrial and academic research once thrived on individual freedom and flair. Progressively for the past three decades or so, however, research has been focused on short-term objectives selected by consensus. Global per-capita growth has steadily declined. Scientific enterprise is losing diversity. Blue Skies Research can help to restore diversity and to create the new technologies that can stimulate growth, but funding agencies nowadays rarely allow total freedom. A new coefficient of adventurousness is described. Its use, or other means, may help restore economic growth to its former levels.

  20. Sky reconstruction for the Tianlai cylinder array

    Science.gov (United States)

    Zhang, Jiao; Zuo, Shi-Fan; Ansari, Reza; Chen, Xuelei; Li, Yi-Chao; Wu, Feng-Quan; Campagne, Jean-Eric; Magneville, Christophe

    2016-10-01

    We apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on spherical harmonic decomposition, and can be applied to a cylindrical array as well as dish arrays and we can compute the instrument response, synthesized beam, transfer function and noise power spectrum. We consider cylinder arrays with feed spacing larger than half a wavelength and, as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome using arrays with a different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configurations.

  1. Sky alert! when satellites fail

    CERN Document Server

    Johnson, Les

    2013-01-01

    How much do we depend on space satellites? Defense, travel, agriculture, weather forecasting, mobile phones and broadband, commerce...the list seems endless. But what would our live be like if the unimaginable happened and, by accident or design, those space assets disappeared? Sky Alert! explores what our world would be like, looking in turn at areas where the loss could have catastrophic effects. The book - demonstrates our dependence on space technology and satellites; - outlines the effect on our economy, defense, and daily lives if satellites and orbiting spacecraft were destroyed; - illustrates the danger of dead satellites, spent rocket stages, and space debris colliding with a functioning satellites; - demonstrates the threat of dramatically increased radiation levels associated with geomagnetic storms; - introduces space as a potential area of conflict between nations.

  2. Full-sky, High-resolution Maps of Interstellar Dust

    Science.gov (United States)

    Meisner, Aaron Michael

    We present full-sky, high-resolution maps of interstellar dust based on data from the Wide-field Infrared Survey Explorer (WISE) and Planck missions. We describe our custom processing of the entire WISE 12 micron All-Sky imaging data set, and present the resulting 15 arcsecond resolution, full-sky map of diffuse Galactic dust emission, free of compact sources and other contaminating artifacts. Our derived 12 micron dust map offers angular resolution far superior to that of all other existing full-sky, infrared dust emission maps, revealing a wealth of small-scale filamentary structure. We also apply the Finkbeiner et al. (1999) two-component thermal dust emission model to the Planck HFI maps. We derive full-sky 6.1 arcminute resolution maps of dust optical depth and temperature by fitting this two-component model to Planck 217-857 GHz along with DIRBE/IRAS 100 micron data. In doing so, we obtain the first ever full-sky 100-3000 GHz Planck-based thermal dust emission model, as well as a dust temperature correction with ~10 times enhanced angular resolution relative to DIRBE-based temperature maps. Analyzing the joint Planck/DIRBE dust spectrum, we show that two-component models provide a better fit to the 100-3000 GHz emission than do single-MBB models, though by a lesser margin than found by Finkbeiner et al. (1999) based on FIRAS and DIRBE. We find that, in diffuse sky regions, our two-component 100-217 GHz predictions are on average accurate to within 2.2%, while extrapolating the Planck Collaboration (2013) single-MBB model systematically underpredicts emission by 18.8% at 100 GHz, 12.6% at 143 GHz and 7.9% at 217 GHz. We calibrate our two-component optical depth to reddening, and compare with reddening estimates based on stellar spectra. We find the dominant systematic problems in our temperature/reddening maps to be zodiacal light on large angular scales and the cosmic infrared background anisotropy on small angular scales. Future work will focus on combining

  3. Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions.

    Science.gov (United States)

    Horváth, Gábor; Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

    2017-02-01

    If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d* for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d > d* is satisfied. Using full-sky imaging polarimetry, we measured the d-pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ. From the measured d-patterns of a given sky we determined the proportion P of the sky for which d > d*. We obtained that P is the largest at low solar elevations θ ≈ 0° and under totally or nearly clear skies with cloud coverage ρ = 0%, when the sun's position is already easily determined. If the sun is below the horizon (-5° ≤ θ see text] under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger's brushes.

  4. Celestial polarization patterns sufficient for Viking navigation with the naked eye: detectability of Haidinger's brushes on the sky versus meteorological conditions

    Science.gov (United States)

    Takács, Péter; Kretzer, Balázs; Szilasi, Szilvia; Száz, Dénes; Farkas, Alexandra; Barta, András

    2017-01-01

    If a human looks at the clear blue sky from which light with high enough degree of polarization d originates, an 8-shaped bowtie-like figure, the yellow Haidinger's brush can be perceived, the long axis of which points towards the sun. A band of high d arcs across the sky at 90° from the sun. A person can pick two points on that band, observe the yellow brushes and triangulate the position of the sun based on the orientation of the two observed brushes. This method has been suggested to have been used on the open sea by Viking navigators to determine the position of the invisible sun occluded by cloud or fog. Furthermore, Haidinger's brushes can also be used to locate the sun when it is below the horizon or occluded by objects on the horizon. To determine the position of the sun using the celestial polarization pattern, the d of the portion of the sky used must be greater than the viewer's degree of polarization threshold d* for perception of Haidinger's brushes. We studied under which sky conditions the prerequisite d > d* is satisfied. Using full-sky imaging polarimetry, we measured the d-pattern of skylight in the blue (450 nm) spectral range for 1296 different meteorological conditions with different solar elevation angles θ and per cent cloud cover ρ. From the measured d-patterns of a given sky we determined the proportion P of the sky for which d > d*. We obtained that P is the largest at low solar elevations θ ≈ 0° and under totally or nearly clear skies with cloud coverage ρ = 0%, when the sun's position is already easily determined. If the sun is below the horizon (−5° ≤ θ < 0°) during twilight, P = 76.17 ± 4.18% for dmin∗=23% under clear sky conditions. Consequently, the sky-polarimetric Viking navigation based on Haidinger's brushes is most useful after sunset and prior to sunrise, when the sun is not visible and large sky regions are bright, clear and polarized enough for perception of Haidinger

  5. Dark Skies Awareness Programs for the U.S. International Year of Astronomy

    Science.gov (United States)

    Walker, Constance E.; U. S. IYA Dark Skies Working Group

    2009-01-01

    The loss of a dark night sky as a natural resource is a growing concern. It impacts not only astronomical research, but also our ecology, health, safety, economics and energy conservation. For this reason, "Dark Skies are a Universal Resource” is one of seven primary themes of the U.S. International Year of Astronomy program in 2009. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved in a variety of dark skies-related programs. To reach this goal, activities have been developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking, Second Life) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize an event in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs, as well as RFI monitoring (e.g., GLOBE at Night and Quiet Skies) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., the Dark Skies Toolkit, Good Neighbor Lighting, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial). To deliver these programs, strategic networks have been established with astronomy clubs (ASP's Night Sky Network's astronomy clubs and the Astronomical League), science and nature centers (Astronomy from the Ground Up and the Association of Science and Technology), educational programs (Project ASTRO and GLOBE) and the International Dark-sky Association. The poster will describe the "know-how” and the means for people to become community advocates in promoting Dark Skies programs as public events at their home institutions. For more information, visit http://astronomy2009

  6. Photometric indicators of visual night sky quality derived from all-sky brightness maps

    Science.gov (United States)

    Duriscoe, Dan M.

    2016-09-01

    Wide angle or fisheye cameras provide a high resolution record of artificial sky glow, which results from the scattering of escaped anthropogenic light by the atmosphere, over the sky vault in the moonless nocturnal environment. Analysis of this record yields important indicators of the extent and severity of light pollution. The following indicators were derived through numerical analysis of all-sky brightness maps: zenithal, average all-sky, median, brightest, and darkest sky brightness. In addition, horizontal and vertical illuminance, resulting from sky brightness were computed. A natural reference condition to which the anthropogenic component may be compared is proposed for each indicator, based upon an iterative analysis of a high resolution natural sky model. All-sky brightness data, calibrated in the V band by photometry of standard stars and converted to luminance, from 406 separate data sets were included in an exploratory analysis. Of these, six locations representing a wide range of severity of impact from artificial sky brightness were selected as examples and examined in detail. All-sky average brightness is the most unbiased indicator of impact to the environment, and is more sensitive and accurate in areas of slight to moderate light pollution impact than zenith brightness. Maximum vertical illuminance provides an excellent indicator of impacts to wilderness character, as does measures of the brightest portions of the sky. Zenith brightness, the workhorse of field campaigns, is compared to the other indicators and found to correlate well with horizontal illuminance, especially at relatively bright sites. The median sky brightness describes a brightness threshold for the upper half of the sky, of importance to telescopic optical astronomy. Numeric indicators, in concert with all-sky brightness maps, provide a complete assessment of visual sky quality at a site.

  7. Euclid Space Mission: building the sky survey

    Science.gov (United States)

    Tereno, I.; Carvalho, C. S.; Dinis, J.; Scaramella, R.; Amiaux, J.; Burigana, C.; Cuillandre, J. C.; da Silva, A.; Derosa, A.; Maiorano, E.; Maris, M.; Oliveira, D.; Franzetti, P.; Garilli, B.; Gomez-Alvarez, P.; Meneghetti, M.; Wachter, S.; Wachter

    2014-05-01

    The Euclid space mission proposes to survey 15000 square degrees of the extragalactic sky during 6 years, with a step-and-stare technique. The scheduling of observation sequences is driven by the primary scientific objectives, spacecraft constraints, calibration requirements and physical properties of the sky. We present the current reference implementation of the Euclid survey and on-going work on survey optimization.

  8. Euclid Space Mission: building the sky survey

    CERN Document Server

    Tereno, I; Dinis, J; Scaramella, R; Amiaux, J; Burigana, C; Cuillandre, J C; da Silva, A; Derosa, A; Maiorano, E; Maris, M; Oliveira, D; Franzetti, P; Garilli, B; Gomez-Alvarez, P; Meneghetti, M; Wachter, S

    2015-01-01

    The Euclid space mission proposes to survey 15000 square degrees of the extragalactic sky during 6 years, with a step-and-stare technique. The scheduling of observation sequences is driven by the primary scientific objectives, spacecraft constraints, calibration requirements and physical properties of the sky. We present the current reference implementation of the Euclid survey and on-going work on survey optimization.

  9. SkyMapper Early Data Release

    Science.gov (United States)

    Wolf, Christian; Onken, Christopher; Schmidt, Brian; Bessell, Michael; Da Costa, Gary; Luvaul, Lance; Mackey, Dougal; Murphy, Simon; White, Marc; SkyMapper Team

    2016-05-01

    The SkyMapper Early Data Release (EDR) is the initial data release from the SkyMapper Southern Survey, which aims to create a deep, multi-epoch, multi-band photometric data set for the entire southern sky. EDR covers approximately 6700 sq. deg. (one-third) of the southern sky as obtained by the Short Survey component of the project. All included fields have at least two visits in good conditions in all six SkyMapper filters (uvgriz). Object catalogues are complete to magnitude 17-18, depending on filter. IVOA-complaint table access protocol (TAP), cone search and simple image access protocol (SIAP) services are available from the SkyMapper website (http://skymapper.anu.edu.au/), as well as through tools such as TOPCAT. Data are restricted to Australian astronomers and their collaborators for twelve months from the release date. Further details on the reduction of SkyMapper data, along with data quality improvements, will be released in late 2016 as part of SkyMapper Data Release 1 (DR1).

  10. Comportamiento de los cultivares de papaya Sunset, Sunrise y de los genotipos Baixinho de Santa Amalia y BH - 65 en la zona sur de la isla de Tenerife Behavior of papaya cultivars Sunset, Sunrise and genotypes of 'Baixinho de Santa Amalia' and BH- 65 in the south of Tenerife island

    Directory of Open Access Journals (Sweden)

    Maria Cristina Rodríguez Pastor

    2010-12-01

    semejante, si bien tienen menor porte en el primer año de cultivo (142,9 y 138,8cm menor altura a la primera flor (40,6 y 42,2 cm y menor longitud de entrenudos (1,4 y 1,3 cm.Las características descriptivas de los frutos son muy parecidas sin existir diferencias significativas entre ellas. Los frutos tienen buen tamaño (13,74 x 7,81 cm y (12,68 x 7,98 cm y peso (392,92 y 418,8 g. y una producción excelente, cualidades de gran interés para el cultivo de la papaya bajo invernadero.The history of the papaya (Carica papaya, L. in the Canary Islands came to show the viability of this crop under greenhouse and the possibility of further expansion in short term due to the introduction, over the last years, of high-quality of commercial cultivars from Hawaii ('Sunrise' and Brazil 'Baixinho de Santa Amalia'(BSA. In this work it was studied the growth, development and productivity of the cultivars Sunset, Sunrise and the genotype BH-65, and 'Baixinho de Santa Amalia', and the morphological and organoleptic characteristics of the fruits, in order to continue with the selection of those cultivars that best adapted and agree with the market requirements, maintain a good productivity in marginal areas for banana production and serve as a basis for future breeding programs. The results show that the highest flowering percentages took place in May (6 months after being planted in hermaphrodite plants for all cultivars, corresponding to 'Sunset' and 'Sunrise' the maximum percentages (80 and 90.4%, respectively. The number of leaves emitted monthly is similar in all cultivars, between 7.5 and 7.8. The female plants of 'Sunrise'and the hermaphrodites of 'Sunset' have greater diameter, and in addition, the last cultivar is precocious in blooming and the fruits are bigger in size and weight. Note also that at the consumption point of the fruit, the cultivar Sunrise showed the highest total soluble solids content (10.33 ° Brix. Moreover, hermaphrodite fruits of 'Sunrise' are the first to

  11. Citotoxicity of food dyes sunset yellow (E-110, bordeaux red (E-123, and tatrazine yellow (E-102 on Allium cepa L. root meristematic cells

    Directory of Open Access Journals (Sweden)

    Keiva Maria Silva Gomes

    2013-03-01

    Full Text Available The objective of this study was to evaluate the cytotoxic effect of the food dyes sunset yellow, bordeaux red, and tartrazine yellow on the cellular cycle of Allium cepa L. Each dye was evaluated at the doses of 0.4 and 4.0 mL, at the exposure times of 24 and 48 hours in root tip cells of Allium cepa L. Slides were prepared and cells were analyzed during the whole cell cycle for cellular aberrations totaling 5,000 total cells for each dose evaluated. The mitotic index was calculated, and statistical analysis was performed using the Chi-squared test (p < 0.05. The results showed that the three dyes used under the evaluated doses and exposure times were cytotoxic to the cells of the system-test used. Further cytotoxicity studies should be conducted for additional results and a proper evaluation of the effect of these three dyes on a cellular level.

  12. 78 FR 69369 - Laminated Woven Sacks From the People's Republic of China: Final Results of the Expedited Sunset...

    Science.gov (United States)

    2013-11-19

    ... method either to an exterior ply of plastic film such as biaxially-oriented polypropylene (BOPP) or to an...'s Republic of China: Countervailing Duty Order, 73 FR 45955 (August 7, 2008). \\2\\ See Initiation of Five-Year (``Sunset'') Reviews, 78 FR 39256 (July 1, 2013). 19 CFR 351.218 (e)(1)(ii)(A) states...

  13. 75 FR 81966 - Top of the Stove Stainless Steel Cooking Ware From the Republic of Korea: Final Results of Sunset...

    Science.gov (United States)

    2010-12-29

    ...'') Review, 75 FR 60731 (October 1, 2010) (Initiation Notice). Because no domestic interested party responded... stove top burners, except tea kettles and fish poachers. On January 24, 1997, and June 17, 1997... Department has determined that no domestic interested party intends to participate in the sunset reviews. On...

  14. 78 FR 47671 - Final Results of Expedited Sunset Reviews of Antidumping Duty Orders: Light-Walled Rectangular...

    Science.gov (United States)

    2013-08-06

    ... May 1, 2013. \\6\\ See Letter from the Directorate of Exports, Ministry of Economy, Republic of Turkey..., Directorate General for Exports, Ministry of Economy, titled ``First Sunset Review of the Antidumping Duty... and Countervailing Duty Centralized Electronic Service System (IA ACCESS). IA ACCESS is available to...

  15. 75 FR 69628 - Non-Frozen Apple Juice Concentrate From the People's Republic of China: Final Results of Sunset...

    Science.gov (United States)

    2010-11-15

    ...-Frozen Apple Juice Concentrate From the People's Republic of China: Final Results of Sunset Review and... the antidumping duty order on non-frozen apple juice concentrate from the People's Republic of China... apple juice concentrate from the PRC. See Notice of Amended Final Determination of Sales at Less Than...

  16. 78 FR 693 - Certain Pasta From Italy: Final Results of the Expedited Third Sunset Review of the...

    Science.gov (United States)

    2013-01-04

    ... Determination: Certain Pasta (``Pasta'') From Italy, 61 FR 38544 (July 24, 1996). On September 4, 2012, the... 1930, as amended (``the Act''). See Initiation of Five-Year (``Sunset'') Review, 77 FR 53867 (September...'') From Italy, 61 FR 38544 (July 24, 1996), remains dispositive. Analysis of Comments Received All...

  17. 78 FR 2368 - Certain Pasta From Italy and Turkey; Final Results of Expedited Third Sunset Reviews of the...

    Science.gov (United States)

    2013-01-11

    ... Determination of Sales at Less Than Fair Value: Certain Pasta From Italy, 61 FR 38547 (July 24, 1996) (``Italian... Fair Value: Certain Pasta From Turkey, 61 FR 38545 (July 24, 1996) (``Turkish Order''). \\2\\ See Notice of Initiation of Five-Year (Sunset) Reviews, 71 FR 53867 (September 4, 2012). On October 4, 2012,...

  18. Precursor wave structure, prereversal vertical drift, and their relative roles in the development of post sunset equatorial spread-F

    Science.gov (United States)

    Abdu, Mangalathayil; Sobral, José; alam Kherani, Esfhan; Batista, Inez S.; Souza, Jonas

    2016-07-01

    The characteristics of large-scale wave structure in the equatorial bottomside F region that are present during daytime as precursor to post sunset development of the spread F/plasma bubble irregularities are investigated in this paper. Digisonde data from three equatorial sites in Brazil (Fortaleza, Sao Luis and Cachimbo) for a period of few months at low to medium/high solar activity phases are analyzed. Small amplitude oscillations in the F layer true heights, representing wave structure in polarization electric field, are identified as upward propagating gravity waves having zonal scale of a few hundred kilometers. Their amplitudes undergo amplification towards sunset, and depending on the amplitude of the prereversal vertical drift (PRE) they may lead to post sunset generation of ESF/plasma bubble irregularities. On days of their larger amplitudes they appear to occur in phase coherence on all days, and correspondingly the PRE vertical drift velocities are larger than on days of the smaller amplitudes of the wave structure that appear at random phase on the different days. The sustenance of these precursor waves structures is supported by the relatively large ratio (approaching unity) of the F region-to- total field line integrated Pedersen conductivities as calculated using the SUPIM simulation of the low latitude ionosphere. This study examines the role of the wave structure relative to that of the prereversal vertical drift in the post sunset spread F irregularity development.

  19. 75 FR 81967 - Porcelain-on-Steel Cooking Ware From Taiwan: Final Results of Sunset Review and Revocation of...

    Science.gov (United States)

    2010-12-29

    ...] Porcelain-on-Steel Cooking Ware From Taiwan: Final Results of Sunset Review and Revocation of Antidumping... of the antidumping duty order on porcelain-on-steel cooking ware (POS cooking ware) from Taiwan... antidumping duty order is porcelain-on-steel cooking ware from Taiwan that does not have self-...

  20. 75 FR 78729 - Notice of Availability of a Draft Environmental Impact Statement for the Sunset Area Community...

    Science.gov (United States)

    2010-12-16

    ... residential and commercial space and public amenities. The redevelopment would include a 1-to-1 unit..., senior center, and/or public library space; a new park/open space; retail shopping and commercial space... mixed uses in the Potential Sunset Terrace Redevelopment Subarea, targeted infrastructure and...

  1. 76 FR 18573 - Notice of Availability of a Final Environmental Impact Statement for the Sunset Area Community...

    Science.gov (United States)

    2011-04-04

    ... services. The Sunset Terrace public housing community units, facilities, and infrastructure are antiquated... properties with mixed-income, mixed-use residential and commercial space and public amenities. The... such as a community center, senior center, and/or public library space; a new park/open space;...

  2. Notice to Nurserymen of the Naming and Release for Propagation of Sahara Sunset, A New African Hibiscus Cultivar

    Science.gov (United States)

    Hibiscus asetosella 'Sahara Sunset' is an African hibiscus released by the United States Department of Agriculture Agricultural Research Service that was Developed by Dr. Cecil Pounders at the Thad Cochran Southern Horticultural Laboratory in Poplarville, MS. ‘Sahara Sunset’ is a tropical shrub (USD...

  3. 76 FR 57019 - Ball Bearings and Parts Thereof From France, Germany and Italy: Final Results of Sunset Reviews...

    Science.gov (United States)

    2011-09-15

    ... International Trade Administration Ball Bearings and Parts Thereof From France, Germany and Italy: Final Results... parts thereof from France, Germany, and Italy. See Initiation of Five-Year (``Sunset'') Review, 76 FR... France, Germany, and Italy. DATES: Effective Date: September 15, 2011. FOR FURTHER INFORMATION...

  4. Solar PV Lighting and Studying after Sunset: Analysis of Micro-benefits in Off-grid Rural Ghana

    Directory of Open Access Journals (Sweden)

    G.Y. Obeng

    2013-02-01

    Full Text Available Solar PV light provides school children living in off-grid rural communities theopportunity to have clean and bright lighting to study after sunset. On the contrary, lightingprovided from poor sources can pollute and adversely affect human eyes during reading andwriting. Using indicator-based questionnaires in cross-sectional surveys, households with andwithout solar PV lighting were surveyed in off-grid rural communities in Ghana. The studyinvestigated lighting and children’s studies after sunset. The results indicated that whereassolar PV light of 5-20 watts dc lamps was sufficient for 5-6 children to study together, lightingfrom kerosene lantern could be sufficient for 1-3 children. All things being equal, the resultsshowed that children who use solar PV light to study upto 2 hours after sunset are likely toimprove on their examination results. The extent to which solar PV lighting significantlyimpacts on studying after sunset was established using some identified indicators. Knowledgeof the results provides understanding of the relative constraints in lighting services faced bychildren in rural communities without access to quality lighting. Such micro-level data willhelp to enhance policy and planning efforts to increase access to clean and renewable energybasedlighting devices to achieve efficient visual comfort in off-grid rural communities.

  5. Relationships between pre-sunset electrojet strength, pre-reversal enhancement and equatorial spread-F onset

    Directory of Open Access Journals (Sweden)

    J. Uemoto

    2010-02-01

    Full Text Available The virtual height of the bottom side F-region (h'F and equatorial spread-F (ESF onsets at Chumphon (10.7° N, 99.4° E; 3.3° N magnetic latitude were compared with the behaviour of equatorial electrojet (EEJ ground strength at Phuket (8.1° N, 98.3° E; 0.1° N magnetic latitude during the period from November 2007 to October 2008. Increase in the F-layer height and ESF onsets during the evening hours were well connected with the EEJ ground strength before sunset, namely, both the height increase and ESF onsets were suppressed when the integrated EEJ ground strength for the period from 1 to 2 h prior to sunset was negative. The finding suggests observationally that the pre-sunset E-region dynamo current and/or electric field are related to the F-region dynamics and ESF onsets around sunset.

  6. 77 FR 777 - Fresh Garlic From the People's Republic of China: Final Results of Expedited Sunset Review of the...

    Science.gov (United States)

    2012-01-06

    ... International Trade Administration Fresh Garlic From the People's Republic of China: Final Results of Expedited...) initiated the third sunset review of the antidumping duty order fresh garlic from the People's Republic of... fresh garlic from the PRC pursuant to section 751(c) of the Act. See Initiation of Five-Year...

  7. 76 FR 60001 - Certain Tin Mill Products From Japan; Final Results of the Second Expedited Sunset Review of the...

    Science.gov (United States)

    2011-09-28

    ... International Trade Administration Certain Tin Mill Products From Japan; Final Results of the Second Expedited...) initiated the second sunset review of the antidumping duty order on certain tin mill products from Japan... duty order on certain tin mill products from Japan pursuant to section 751(c) of the Act....

  8. Determination of sunset yellow in multi-vitamin tablets by photoacoustic spectroscopy and a comparison with alternative methods

    NARCIS (Netherlands)

    Doka, O.; Bicanic, D.D.; Ajtony, Z.; Koehorst, R.B.M.

    2005-01-01

    Photoacoustic (PA) spectroscopy in the visible wavelength region was shown to be suitable for a direct (no preparatory steps involved) quantification of sunset yellow (E110) colour in effervescent multi-vitamin tablets. Measurements on powdered tablets containing E110 were performed at 480?nm at whi

  9. Retrieval of the optical depth using an all-sky CCD camera.

    Science.gov (United States)

    Olmo, Francisco J; Cazorla, Alberto; Alados-Arboledas, Lucas; López-Alvarez, Miguel A; Hernández-Andrés, Javier; Romero, Javier

    2008-12-01

    A new method is presented for retrieval of the aerosol and cloud optical depth using a CCD camera equipped with a fish-eye lens (all-sky imager system). In a first step, the proposed method retrieves the spectral radiance from sky images acquired by the all-sky imager system using a linear pseudoinverse algorithm. Then, the aerosol or cloud optical depth at 500 nm is obtained as that which minimizes the residuals between the zenith spectral radiance retrieved from the sky images and that estimated by the radiative transfer code. The method is tested under extreme situations including the presence of nonspherical aerosol particles. The comparison of optical depths derived from the all-sky imager with those retrieved with a sunphotometer operated side by side shows differences similar to the nominal error claimed in the aerosol optical depth retrievals from sunphotometer networks.

  10. BIG SKY CARBON SEQUESTRATION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2004-06-01

    The Big Sky Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts during the second performance period fall into four areas: evaluation of sources and carbon sequestration sinks; development of GIS-based reporting framework; designing an integrated suite of monitoring, measuring, and verification technologies; and initiating a comprehensive education and outreach program. At the first two Partnership meetings the groundwork was put in place to provide an assessment of capture and storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other western DOE partnerships. Efforts are also being made to find funding to include Wyoming in the coverage areas for both geological and terrestrial sinks and sources. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts begun in developing and implementing MMV technologies for geological sequestration reflect this concern. Research is also underway to identify and validate best management practices for

  11. The new world atlas of artificial night sky brightness

    CERN Document Server

    Falchi, Fabio; Duriscoe, Dan; Kyba, Christopher C M; Elvidge, Christopher D; Baugh, Kimberly; Portnov, Boris A; Rybnikova, Nataliya A; Furgoni, Riccardo

    2016-01-01

    Artificial lights raise night sky luminance, creating the most visible effect of light pollution-artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world's land surfaces between 75{\\deg}N and 60{\\deg}S, 88% of Europe, and almost half of the United States experience light-polluted nights.

  12. The new world atlas of artificial night sky brightness.

    Science.gov (United States)

    Falchi, Fabio; Cinzano, Pierantonio; Duriscoe, Dan; Kyba, Christopher C M; Elvidge, Christopher D; Baugh, Kimberly; Portnov, Boris A; Rybnikova, Nataliya A; Furgoni, Riccardo

    2016-06-01

    Artificial lights raise night sky luminance, creating the most visible effect of light pollution-artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world's land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light-polluted nights.

  13. Spatiotemporal change of sky polarization during the total solar eclipse on 29 March 2006 in Turkey: polarization patterns of the eclipsed sky observed by full-sky imaging polarimetry.

    Science.gov (United States)

    Sipocz, Brigitta; Hegedüs, Ramón; Kriska, György; Horváth, Gábor

    2008-12-01

    Using 180 degrees field-of-view (full-sky) imaging polarimetry, we measured the spatiotemporal change of the polarization of skylight during the total solar eclipse on 29 March 2006 in Turkey. We present our observations here on the temporal variation of the celestial patterns of the degree p and angle alpha of linear polarization of the eclipsed sky measured in the red (650 nm), green (550 nm), and blue (450 nm) parts of the spectrum. We also report on the temporal and spectral change of the positions of neutral (unpolarized, p = 0) points, and points with local minima or maxima of p of the eclipsed sky. Our results are compared with the observations performed by the same polarimetric technique during the total solar eclipse on 11 August 1999 in Hungary. Practically the same characteristics of celestial polarization were encountered during both eclipses. This shows that the observed polarization phenomena of the eclipsed sky may be general.

  14. Measurement of fine particulate matter nonvolatile and semi-volatile organic material with the Sunset Laboratory Carbon Aerosol Monitor.

    Science.gov (United States)

    Grover, Brett D; Kleinman, Michael; Eatough, Norman L; Eatough, Delbert J; Cary, Robert A; Hopke, Philip K; Wilson, William E

    2008-01-01

    Semi-volatile organic material (SVOM) in fine particles is not reliably measured with conventional semicontinuous carbon monitors because SVOM is lost from the collection media during sample collection. We have modified a Sunset Laboratory Carbon Aerosol Monitor to allow for the determination of SVOM. In a conventional Sunset monitor, gas-phase organic compounds are removed in the sampled airstream by a diffusion denuder employing charcoal-impregnated cellulose filter (CIF) surfaces. Subsequently, particles are collected on a quartz filter and the instrument then determines both the organic carbon and elemental carbon fractions of the aerosol using a thermal/optical method. However, some of the SVOM is lost from the filter during collection, and therefore is not determined. Because the interfering gas-phase organic compounds are removed before aerosol collection, the SVOM can be determined by filtering the particles at the instrument inlet and then replacing the quartz filter in the monitor with a charcoal-impregnated glass fiber filter (CIG), which retains the SVOM lost from particles collected on the inlet filter. The resulting collected SVOM is then determined in the analysis step by measurement of the carbonaceous material thermally evolved from the CIG filter. This concept was tested during field studies in February 2003 in Lindon, UT, and in July 2003 in Rubidoux, CA. The results obtained were validated by comparison with Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) results. The sum of nonvolatile organic material determined with a conventional Sunset monitor and SVOM determined with the modified Sunset monitor agree with the PC-BOSS results. Linear regression analysis of total carbon concentrations determined by the PC-BOSS and the Sunset resulted in a zero-intercept slope of 0.99 +/- 0.02 (R2 = 0.92) and a precision of sigma = +/- 1.5 microg C/m3 (8%).

  15. Simulations of the Microwave Sky

    Energy Technology Data Exchange (ETDEWEB)

    Sehgal, Neelima; /KIPAC, Menlo Park; Bode, Paul; /Princeton U., Astrophys. Sci. Dept.; Das, Sudeep; /Princeton U., Astrophys. Sci. Dept. /Princeton U.; Hernandez-Monteagudo, Carlos; /Garching, Max Planck Inst.; Huffenberger, Kevin; /Miami U.; Lin, Yen-Ting; /Tokyo U., IPMU; Ostriker, Jeremiah P.; /Princeton U., Astrophys. Sci. Dept.; Trac, Hy; /Harvard-Smithsonian Ctr. Astrophys.

    2009-12-16

    We create realistic, full-sky, half-arcminute resolution simulations of the microwave sky matched to the most recent astrophysical observations. The primary purpose of these simulations is to test the data reduction pipeline for the Atacama Cosmology Telescope (ACT) experiment; however, we have widened the frequency coverage beyond the ACT bands and utilized the easily accessible HEALPix map format to make these simulations applicable to other current and near future microwave background experiments. Some of the novel features of these simulations are that the radio and infrared galaxy populations are correlated with the galaxy cluster and group populations, the primordial microwave background is lensed by the dark matter structure in the simulation via a ray-tracing code, the contribution to the thermal and kinetic Sunyaev-Zel'dovich (SZ) signals from galaxy clusters, groups, and the intergalactic medium has been included, and the gas prescription to model the SZ signals has been refined to match the most recent X-ray observations. The cosmology adopted in these simulations is also consistent with the WMAP 5-year parameter measurements. From these simulations we find a slope for the Y{sub 200} - M{sub 200} relation that is only slightly steeper than self-similar, with an intrinsic scatter in the relation of {approx} 14%. Regarding the contamination of cluster SZ flux by radio galaxies, we find for 148 GHz (90 GHz) only 3% (4%) of halos have their SZ decrements contaminated at a level of 20% or more. We find the contamination levels higher for infrared galaxies. However, at 90 GHz, less than 20% of clusters with M{sub 200} > 2.5 x 10{sup 14}M{sub {circle_dot}} and z < 1.2 have their SZ decrements filled in at a level of 20% or more. At 148 GHz, less than 20% of clusters with M{sub 200} > 2.5 x 10{sup 14}M{sub {circle_dot}} and z < 0.8 have their SZ decrements filled in at a level of 50% or larger. Our models also suggest that a population of very high flux

  16. BIG SKY CARBON SEQUESTRATION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2005-01-31

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I fall into four areas: evaluation of sources and carbon sequestration sinks that will be used to determine the location of pilot demonstrations in Phase II; development of GIS-based reporting framework that links with national networks; designing an integrated suite of monitoring, measuring, and verification technologies and assessment frameworks; and initiating a comprehensive education and outreach program. The groundwork is in place to provide an assessment of storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research. Efforts are underway to showcase the architecture of the GIS framework and initial results for sources and sinks. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other western DOE partnerships. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts in developing and implementing MMV technologies for geological sequestration reflect this concern. Research is

  17. Highly sensitive determination of sunset yellow FCF (E110) in food products based on Chitosan/Nanoparticles/MWCNTs with modified gold electrode

    Science.gov (United States)

    Rovina, K.; Siddiquee, S.; Shaarani, S. M.

    2016-06-01

    Sunset Yellow belongs to the family of azo dyes, commonly used in food industry. High consumption of Sunset Yellow can cause health problem to human. Due to arising of the health issues, there are several analytical methods available for determination of Sunset Yellow. However, these methods are required skilled manpower, complicated procedures, time consuming and high cost. Herein, an electrochemical sensor was developed based on the combination of chitosan (CHIT), calcium oxide nanoparticles (CaONPs) and multiwall carbon nanotubes (MWCNTs) sensing film for detection of Sunset Yellow in food products. Electrochemical behavior of the modified gold electrode in the presence of Sunset Yellow was studied by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The morphological characteristics of CHIT/CaONPs/MWCNTs were observed under scanning electron microscope and transmission electron microscope. Under optimal conditions, the DPV was detected with different concentrations of Sunset Yellow in the range of 0.9 to 10 ppm, with detection limit of 0.8 ppm. The developed method has successfully applied for monitoring the presence of Sunset Yellow with different food products including candy, royal jelly, ice cream and soft drink with satisfactory results.

  18. Designing institutions for global democracy: flexibility through escape clauses and sunset provisions

    Directory of Open Access Journals (Sweden)

    Jonathan W. Kuyper

    2013-12-01

    Full Text Available How can advocates of global democracy grapple with the empirical conditions that constitute world politics? I argue that flexibility mechanisms—;commonly used to advance international cooperation—should be employed to make the institutional design project of global democracy more tractable. I highlight three specific reasons underpinning this claim. First, flexibility provisions make bargaining over different institutional designs more manageable. Second, heightened flexibility takes seriously potential concerns about path-dependent institutional development. Finally, deliberately shortening the time horizons of agents by employing flexibility provisions has cognitive benefits as it forces designers to focus specifically on issues of feasibility as well as desirability. I discuss a range of flexibility mechanisms and highlight the utility of sunset provisions and escape clauses. From this analysis, I build an argument for the usage of small-scale democratic experiments through which citizens (or their representatives have a say in global policy making.

  19. Monitoring All Sky for Variability

    CERN Document Server

    Paczynski, B

    2000-01-01

    A few percent of all stars are variable, yet over 90% of variables brighter than 12 magnitude have not been discovered yet. There is a need for an all sky search and for the early detection of any unexpected events: optical flashes from gamma-ray bursts, novae, dwarf novae, supernovae, `killer asteroids'. The ongoing projects like ROTSE, ASAS, TASS, and others, using instruments with just 4 inch aperture, have already discovered thousands of new variable stars, a flash from an explosion at a cosmological distance, and the first partial eclipse of a nearby star by its Jupiter like planet. About one million variables may be discovered with such small instruments, and many more with larger telescopes. The critical elements are software and full automation of the hardware. A complete census of the brightest eclipsing binaries is needed to select objects for a robust empirical calibration of the the accurate distance determination to the Magellanic Clouds, the first step towards the Hubble constant. An archive to ...

  20. Big Sky Carbon Sequestration Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Susan Capalbo

    2005-12-31

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I are organized into four areas: (1) Evaluation of sources and carbon sequestration sinks that will be used to determine the location of pilot demonstrations in Phase II; (2) Development of GIS-based reporting framework that links with national networks; (3) Design of an integrated suite of monitoring, measuring, and verification technologies, market-based opportunities for carbon management, and an economic/risk assessment framework; (referred to below as the Advanced Concepts component of the Phase I efforts) and (4) Initiation of a comprehensive education and outreach program. As a result of the Phase I activities, the groundwork is in place to provide an assessment of storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that complements the ongoing DOE research agenda in Carbon Sequestration. The geology of the Big Sky Carbon Sequestration Partnership Region is favorable for the potential sequestration of enormous volume of CO{sub 2}. The United States Geological Survey (USGS 1995) identified 10 geologic provinces and 111 plays in the region. These provinces and plays include both sedimentary rock types characteristic of oil, gas, and coal productions as well as large areas of mafic volcanic rocks. Of the 10 provinces and 111 plays, 1 province and 4 plays are located within Idaho. The remaining 9 provinces and 107 plays are dominated by sedimentary rocks and located in the states of Montana and Wyoming. The potential sequestration capacity of the 9 sedimentary provinces within the region ranges from 25,000 to almost 900,000 million metric tons of CO{sub 2}. Overall every sedimentary formation investigated

  1. Pre-Dawn Martian Sky

    Science.gov (United States)

    1997-01-01

    On Sol 39 there were wispy blue clouds in the pre-dawn sky of Mars, as seen by the Imager for Mars Pathfinder (IMP). The color image was made by taking blue, green, and red images and then combining them into a single color image. The clouds appear to have a bluish side and a greenish side because they moved (in the wind from the northeast) between images. This picture was made an hour and twenty minutes before sunrise -- the sun is not shining directly on the water ice clouds, but they are illuminated by the dawn twilight.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  2. Sky dancer: an intermittent system

    Science.gov (United States)

    Cros, Anne; Rodríguez Romero, Jesse Alexander; Damián Díaz Andrade, Oscar

    2009-11-01

    Sky dancers attract people sight to make advertising. What is the origin of those large vertical tubes fluctuations above an air blower? This study complements the previous one [1] about the system analysis from a dynamical system point of view. As a difference from the ``garden hose-instability'' [2], the tube shape has got ``break points''. Those ``break points'' separate the air-filled bottom tube portion from its deflated top portion. We record the tube dynamics with a high-speed videocamera simultaneously that we measure the pressure at the air blower exit. The intermittent pressure evolution displays picks when the tube fluctuates. We compare those overpressure values with the ones that appears in a rigid tube whose exit is partially obstructed. [1] F. Castillo Flores & A. Cros ``Transition to chaos of a vertical collapsible tube conveying air flow'' J. Phys.: Conf. Ser. 166, 012017 (2009). [2] A. S. Greenwald & J. Dungundji ``Static and dynamic instabilities of a propellant line'' MIT Aeroelastic and Structures Research Lab, AFOSR Sci. Report: AFOSR 67-1395 (1967).

  3. BIG SKY CARBON SEQUESTRATION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2004-06-01

    The Big Sky Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts during the second performance period fall into four areas: evaluation of sources and carbon sequestration sinks; development of GIS-based reporting framework; designing an integrated suite of monitoring, measuring, and verification technologies; and initiating a comprehensive education and outreach program. At the first two Partnership meetings the groundwork was put in place to provide an assessment of capture and storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other western DOE partnerships. Efforts are also being made to find funding to include Wyoming in the coverage areas for both geological and terrestrial sinks and sources. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts begun in developing and implementing MMV technologies for geological sequestration reflect this concern. Research is also underway to identify and validate best management practices for

  4. Detecting Rainfall Onset Using Sky Images

    CERN Document Server

    Dev, Soumyabrata; Lee, Yee Hui; Winkler, Stefan

    2016-01-01

    Ground-based sky cameras (popularly known as Whole Sky Imagers) are increasingly used now-a-days for continuous monitoring of the atmosphere. These imagers have higher temporal and spatial resolutions compared to conventional satellite images. In this paper, we use ground-based sky cameras to detect the onset of rainfall. These images contain additional information about cloud coverage and movement and are therefore useful for accurate rainfall nowcast. We validate our results using rain gauge measurement recordings and achieve an accuracy of 89% for correct detection of rainfall onset.

  5. Angle of sky light polarization derived from digital images of the sky under various conditions.

    Science.gov (United States)

    Zhang, Wenjing; Cao, Yu; Zhang, Xuanzhe; Yang, Yi; Ning, Yu

    2017-01-20

    Skylight polarization is used for navigation by some birds and insects. Skylight polarization also has potential for human navigation applications. Its advantages include relative immunity from interference and the absence of error accumulation over time. However, there are presently few examples of practical applications for polarization navigation technology. The main reason is its weak robustness during cloudy weather conditions. In this paper, the real-time measurement of the sky light polarization pattern across the sky has been achieved with a wide field of view camera. The images were processed under a new reference coordinate system to clearly display the symmetrical distribution of angle of polarization with respect to the solar meridian. A new algorithm for the extraction of the image axis of symmetry is proposed, in which the real-time azimuth angle between the camera and the solar meridian is accurately calculated. Our experimental results under different weather conditions show that polarization navigation has high accuracy, is strongly robust, and performs well during fog and haze, clouds, and strong sunlight.

  6. Characterization of Light at Night Data from Select SkyGlowNet Nodes

    Science.gov (United States)

    Flurchick, K. M.; Deal, S.; Foster, C.

    2013-05-01

    Internet-enabled sky brightness meters (iSBMs) that continuously record and log sky brightness at the zenith have been installed at the prototype nodes of a network called SkyGlowNet. Also logged are time and weather information. These data are polled at a user-defined frequency, typically about every 45 seconds. Although the SkyGlowNetdata are used for various professional scientific studies, they are also useful for independent student research projects. In this case, the data are uploaded to the SkyGlowNetwebsite, initially to a proprietary area where the data for each institution are embargoed for one or two semesters as students conduct research projects with their data. When released from embargo, the data are moved to another area where they can be accessed by all SkyGlowNet participants. In this paper, we describe a student project in which the data collected at two SkyGlowNet sites are characterized. The data streams are parsed into homogenous segments and statistical tools are employed to describe variations observed in the data values. We demonstrate how to differentiate between natural phenomena and the effects of artificial lighting on the brightness of the night sky. In our poster we show how these effects compare between sites as separate as Arizona and North Carolina. We also have experimented with the development of statistical metrics that are used to help categorize sky brightness on select nights, and can nearly automatically provide a characterization of the quality of the night sky for astronomical purposes.

  7. Progressive effects of the interaction of Sodium nitrite and sunset yellow on different physiological parameters in albino rats

    Directory of Open Access Journals (Sweden)

    Eman. G.E. Helal

    2001-06-01

    Full Text Available It has been noticed that the Egyptian children usually eat and drink food containing both food preservative and food colourants at the same time . This has attracted the attention to study the interaction between one of food preservatives (sodium nitrite and a food coloring agent (sunset yellow. The mixture of the two agents at the limited dose of each was found to be a lethal dose. So, 1/10th of this dose was used daily for 30 days. Animals were devided into three groups. The first group served as a control, while the second group was orally administered a mixture of 10mg sod. nitrite (NaNO3/kg and 0.5 mg/ kg /day sun set yellow (S.S.Y/. The third group received selenium (5 mcg/kg in addition to the above mentioned mixture. After 30 days of treatment, half of the animals from each group were decapitated. The other half of animals was left for another 15 days without treatment for recovery. Ingestion of the mixture of (NaNO3 and S.S.Y significantly decreased rat body weight, R B C and WBC counts, Hb %. , Hct %. Serum inorganic phosphorus, serum protein and serum albumin. Significant increases were observed in serum glucose, T3, T4, calcium, GGT, LDH, Cpk, ALK.ph and cholesterol. Also cholesterol of brain, liver and heart were significantly elevated. No changes were recorded for organ/ body weight, respiratory rate, heart beats, rectal temperature, AST and ALT activities of serum and tissues, acid phosphatase activity, total lipids of serum and tissues, cholesterol of muscle and kidney and serum triglycerides A complete recovery from the abnormalities of most biochemical and haematological parameters was observed after 15 days recovery or when selenium was administered This draws attention to the dangers of interactions of such preservatives and colorants. The present study showed that even the permitted doses of colourants and food preservatives may be harmful.

  8. A Machine-Learning-Driven Sky Model.

    Science.gov (United States)

    Satylmys, Pynar; Bashford-Rogers, Thomas; Chalmers, Alan; Debattista, Kurt

    2017-01-01

    Sky illumination is responsible for much of the lighting in a virtual environment. A machine-learning-based approach can compactly represent sky illumination from both existing analytic sky models and from captured environment maps. The proposed approach can approximate the captured lighting at a significantly reduced memory cost and enable smooth transitions of sky lighting to be created from a small set of environment maps captured at discrete times of day. The author's results demonstrate accuracy close to the ground truth for both analytical and capture-based methods. The approach has a low runtime overhead, so it can be used as a generic approach for both offline and real-time applications.

  9. Sky cover from MFRSR observations: cumulus clouds

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-01-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their model clear-sky counterparts are two main components of a new method for estimating the fractional sky cover of different cloud types, including cumulus clouds. The performance of this method is illustrated using 1-min resolution data from ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumulus clouds. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  10. From Telluric (Earth) To Tectonic (Sky)

    OpenAIRE

    Buchanan, Christopher Taylor

    2008-01-01

    My graduate thesis is a study of telluric and tectonic architecture. These two ideas inspired me to design a baseball stadium for the town of Blacksburg, Virginia that portrayed the contrasting concepts "of the earth" and "of the sky."

  11. Big Sky Carbon Sequestration Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2005-11-01

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I fall into four areas: evaluation of sources and carbon sequestration sinks that will be used to determine the location of pilot demonstrations in Phase II; development of GIS-based reporting framework that links with national networks; designing an integrated suite of monitoring, measuring, and verification technologies and assessment frameworks; and initiating a comprehensive education and outreach program. The groundwork is in place to provide an assessment of storage capabilities for CO2 utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research agenda in Carbon Sequestration. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other DOE regional partnerships. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts in developing and implementing MMV technologies for geological sequestration reflect this concern. Research is also underway to identify and validate best management practices for soil C in the

  12. BIG SKY CARBON SEQUESTRATION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2004-10-31

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership fall into four areas: evaluation of sources and carbon sequestration sinks; development of GIS-based reporting framework; designing an integrated suite of monitoring, measuring, and verification technologies; and initiating a comprehensive education and outreach program. At the first two Partnership meetings the groundwork was put in place to provide an assessment of capture and storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research. During the third quarter, planning efforts are underway for the next Partnership meeting which will showcase the architecture of the GIS framework and initial results for sources and sinks, discuss the methods and analysis underway for assessing geological and terrestrial sequestration potentials. The meeting will conclude with an ASME workshop. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other western DOE partnerships. Efforts are also being made to find funding to include Wyoming in the coverage areas for both geological and terrestrial sinks and sources. The Partnership recognizes the critical importance of measurement, monitoring, and verification

  13. Big Sky Carbon Sequestration Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Susan Capalbo

    2005-12-31

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I are organized into four areas: (1) Evaluation of sources and carbon sequestration sinks that will be used to determine the location of pilot demonstrations in Phase II; (2) Development of GIS-based reporting framework that links with national networks; (3) Design of an integrated suite of monitoring, measuring, and verification technologies, market-based opportunities for carbon management, and an economic/risk assessment framework; (referred to below as the Advanced Concepts component of the Phase I efforts) and (4) Initiation of a comprehensive education and outreach program. As a result of the Phase I activities, the groundwork is in place to provide an assessment of storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that complements the ongoing DOE research agenda in Carbon Sequestration. The geology of the Big Sky Carbon Sequestration Partnership Region is favorable for the potential sequestration of enormous volume of CO{sub 2}. The United States Geological Survey (USGS 1995) identified 10 geologic provinces and 111 plays in the region. These provinces and plays include both sedimentary rock types characteristic of oil, gas, and coal productions as well as large areas of mafic volcanic rocks. Of the 10 provinces and 111 plays, 1 province and 4 plays are located within Idaho. The remaining 9 provinces and 107 plays are dominated by sedimentary rocks and located in the states of Montana and Wyoming. The potential sequestration capacity of the 9 sedimentary provinces within the region ranges from 25,000 to almost 900,000 million metric tons of CO{sub 2}. Overall every sedimentary formation investigated

  14. Big Sky Carbon Sequestration Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2005-11-01

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I fall into four areas: evaluation of sources and carbon sequestration sinks that will be used to determine the location of pilot demonstrations in Phase II; development of GIS-based reporting framework that links with national networks; designing an integrated suite of monitoring, measuring, and verification technologies and assessment frameworks; and initiating a comprehensive education and outreach program. The groundwork is in place to provide an assessment of storage capabilities for CO2 utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research agenda in Carbon Sequestration. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other DOE regional partnerships. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts in developing and implementing MMV technologies for geological sequestration reflect this concern. Research is also underway to identify and validate best management practices for soil C in the

  15. Exploring the Variable Sky with Linear. 1. Photometric Recalibration with the Sloan Digital Sky Survey

    Science.gov (United States)

    2011-12-01

    moonlight (to within 3 days of the full moon ), scattered clouds, and airglow. LINEAR images are frequently taken under skies as bright asμV = 16 mag...of 25 nights per lunation, taking off 4–5 nights around the full moon . After accounting for weather and equipment problems, about 20 observing nights...and after the full moon . To efficiently cover the available sky at minimal airmass, each telescope is assigned a strip of sky that is aligned with

  16. Aladin Lite: Lightweight sky atlas for browsers

    Science.gov (United States)

    Boch, Thomas

    2014-02-01

    Aladin Lite is a lightweight version of the Aladin tool, running in the browser and geared towards simple visualization of a sky region. It allows visualization of image surveys (JPEG multi-resolution HEALPix all-sky surveys) and permits superimposing tabular (VOTable) and footprints (STC-S) data. Aladin Lite is powered by HTML5 canvas technology and is easily embeddable on any web page and can also be controlled through a Javacript API.

  17. The Mythology of the Night Sky

    Science.gov (United States)

    Falkner, David E.

    The word "planet" comes from the Latin word planeta and the Greek word planes, which means "wanderer." When the ancient Greeks studied the night sky they noticed that most of the stars remained in the same position relative to all the other stars, but a few stars seem to move in the sky from day to day, week to week, and month to month. The Greeks called these rogue stars "wanderers" because they wandered through the starry background.

  18. Estimation of solar irradiance using ground-based whole sky imagers

    CERN Document Server

    Dev, Soumyabrata; Lee, Yee Hui; Winkler, Stefan

    2016-01-01

    Ground-based whole sky imagers (WSIs) can provide localized images of the sky of high temporal and spatial resolution, which permits fine-grained cloud observation. In this paper, we show how images taken by WSIs can be used to estimate solar radiation. Sky cameras are useful here because they provide additional information about cloud movement and coverage, which are otherwise not available from weather station data. Our setup includes ground-based weather stations at the same location as the imagers. We use their measurements to validate our methods.

  19. Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993

    Science.gov (United States)

    Mclean, Ian S.

    1994-01-01

    Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.

  20. Frequency of College Students' Night-Sky Watching Behaviors

    Science.gov (United States)

    Kelly, William E.; Kelly, Kathryn E.; Batey, Jason

    2006-01-01

    College students (N = 112) completed the Noctcaelador Inventory, a measure of psychological attachment to the night-sky, and estimated various night-sky watching related activities: frequency and duration of night-sky watching, astro-tourism, ownership of night-sky viewing equipment, and attendance of observatories or planetariums. The results…

  1. Educating for the Preservation of Dark Skies

    Science.gov (United States)

    Preston, Sandra Lee; Cianciolo, Frank; Wetzel, Marc; Finkelstein, Keely; Wren, William; Nance, Craig

    2015-08-01

    The stars at night really are big and bright deep in the heart of Texas at the McDonald Observatory near Fort Davis, Texas. Each year 80,000 visitors from all over the world make the pilgrimage to the Observatory to attend one of the three-times-a-week star parties. Many experience, for the first time, the humbling, splendor of a truly dark night sky. Over the last several years, the Observatory has experienced dramatic increases in visitation demonstrating the public’s appetite for science education, in general, and interest in the night sky, in particular. This increasing interest in astronomy is, ironically, occurring at a time when most of humanity’s skies are becoming increasingly light-polluted frustrating this natural interest. Dark skies and knowledgeable education and outreach staff are an important resource in maintaining the public’s interest in astronomy, support for astronomical research, and local tourism.This year Observatory educators were inspired by the observance of the International Year of Light to promote healthy outdoor lighting through its popular Astronomy Day distance learning program. This program reaches tens of thousands of K-12 students in Texas and other states with a message of how they can take action to preserve dark skies. As well, more than a thousand Boy Scouts visiting during the summer months receive a special program, which includes activities focusing on good lighting practices, thereby earning them credits toward an astronomy badge.The Observatory also offers a half-a-dozen K-12 teacher professional development workshops onsite each year, which provide about 90 teachers with dark skies information, best-practice lighting demonstrations, and red flashlights. Multi-year workshops for National Park and State of Texas Parks personnel are offered on dark sky preservation and sky interpretation at McDonald and a Dark Skies fund for retrofitting lights in the surrounding area has been established. The Observatory also uses

  2. Algorithm of sky-ground-wave signal separation in CDMA system

    Institute of Scientific and Technical Information of China (English)

    Zhang Jingjuan; Chen Shiru

    2008-01-01

    To solve the problem of the sky-wave interference in radio positioning system operating in CDMA mode, an algorithm of sky-ground-wave separation is provided. Based on the MLE (maximum likelihood estimate),and by estimating the amplitude and the phase of the sky-wave signal, the provided algorithm for separating sky-ground-wave is implemented. The mathematics model used for signal processing is established, and the possible solutions are provided. The structure and signal processing flow implementing the presented algorithm in the receiver are presented. A multi-channels signal searching idea is adopted, some of which process the sky-wave signal, and some of which process the ground-wave signal. Numerical analysis and simulation show that the proposed algorithm has higher accuracy, more rapid processing speed, and simpler implementation for the estimation of the sky-wave signal parameter, and can separate the sky-wave signal and ground-wave signal from the arrival combination signal effectively.

  3. Receptive fields of locust brain neurons are matched to polarization patterns of the sky.

    Science.gov (United States)

    Bech, Miklós; Homberg, Uwe; Pfeiffer, Keram

    2014-09-22

    Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation.

  4. The night sky brightness at Potsdam-Babelsberg including overcast and moonlit conditions

    Science.gov (United States)

    Puschnig, Johannes; Schwope, Axel; Posch, Thomas; Schwarz, Robert

    2014-05-01

    We analyze the results of 2 years (2011-2012) of night sky photometry performed at the Leibniz Institute for Astrophysics in Potsdam-Babelsberg. This institute is located 23 km to the southwest of the center of Berlin. Our measurements have been performed with a Sky Quality Meter. We find night sky brightness values ranging from 16.5 to 20.3 magSQM arcsec-2; the latter value corresponds to 4.8 times the natural zenithal night sky brightness. We focus on the influence of clouds and of the moon on the night sky brightness. It turns out that Potsdam-Babelsberg, despite its proximity to Berlin, still shows a significant correlation of the night sky brightness with the lunar phases. However, the light-pollution-enhancing effect of clouds dominates the night sky brightness by far: overcast nights (up to 16.5 magSQM arcsec-2) are much brighter than clear full moon nights (18-18.5 magSQM arcsec-2).

  5. SiO2@Au nanoshells-based SERS method for detection of sunset yellow and chrysoidine.

    Science.gov (United States)

    Xie, Yunfei; Chen, Ting; Cheng, Yuliang; Wang, Heya; Qian, He; Yao, Weirong

    2014-11-11

    A novel surface-enhanced Raman scattering (SERS) substrate made up of SiO2@Au nanoshells has been developed for detecting sunset yellow and chrysoidine. It exhibits an excellent enrichment SERS effect on these two colorant molecules. In this work, density functional theory (DFT) calculations have been carried out to determine the molecular structure and theoretical Raman spectra. This provided a good description of the characteristic peaks of the molecules. In addition, the appropriate thicknesses of the shell and environment pH have been derived to obtain improved SERS signals. The lowest concentration is 1 ppm and 0.5 ppm for sunset yellow and chrysoidine, respectively. Under optimal detection condition, it has proved possible to distinguish each colorant by its characteristic peaks in the SERS spectra of a mixture of the two colorants.

  6. BIG SKY CARBON SEQUESTRATION PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Capalbo

    2004-10-31

    The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership fall into four areas: evaluation of sources and carbon sequestration sinks; development of GIS-based reporting framework; designing an integrated suite of monitoring, measuring, and verification technologies; and initiating a comprehensive education and outreach program. At the first two Partnership meetings the groundwork was put in place to provide an assessment of capture and storage capabilities for CO{sub 2} utilizing the resources found in the Partnership region (both geological and terrestrial sinks), that would complement the ongoing DOE research. During the third quarter, planning efforts are underway for the next Partnership meeting which will showcase the architecture of the GIS framework and initial results for sources and sinks, discuss the methods and analysis underway for assessing geological and terrestrial sequestration potentials. The meeting will conclude with an ASME workshop. The region has a diverse array of geological formations that could provide storage options for carbon in one or more of its three states. Likewise, initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil C on forested, agricultural, and reclaimed lands. Both options include the potential for offsetting economic benefits to industry and society. Steps have been taken to assure that the GIS-based framework is consistent among types of sinks within the Big Sky Partnership area and with the efforts of other western DOE partnerships. Efforts are also being made to find funding to include Wyoming in the coverage areas for both geological and terrestrial sinks and sources. The Partnership recognizes the critical importance of measurement, monitoring, and verification

  7. An Innovative Collaboration on Dark Skies Education

    Science.gov (United States)

    Walker, Constance E.; Mayer, M.; EPO Students, NOAO

    2011-01-01

    Dark night skies are being lost all over the globe, and hundreds of millions of dollars of energy are being wasted in the process.. Improper lighting is the main cause of light pollution. Light pollution is a concern on many fronts, affecting safety, energy conservation, cost, human health, and wildlife. It also robs us of the beauty of viewing the night sky. In the U.S. alone, over half of the population cannot see the Milky Way from where they live. To help address this, the National Optical Astronomy Observatory Education and Public Outreach (NOAO EPO) staff created two programs: Dark Skies Rangers and GLOBE at Night. Through the two programs, students learn about the importance of dark skies and experience activities that illustrate proper lighting, light pollution's effects on wildlife and how to measure the darkness of their skies. To disseminate the programs locally in an appropriate yet innovative venue, NOAO partnered with the Cooper Center for Environmental Learning in Tucson, Arizona. Operated by the largest school district in Tucson and the University of Arizona College of Education, the Cooper Center educates thousands of students and educators each year about ecology, science, and the beauty and wonders of the Sonoran Desert. During the first academic year (2009-2010), we achieved our goal of reaching nearly 20 teachers in 40 classrooms of 1000 students. We gave two 3-hour teacher-training sessions and provided nineteen 2.5-hour on-site evening sessions on dark skies activities for the students of the teachers trained. One outcome of the program was the contribution of 1000 "GLOBE at Night 2010” night-sky brightness measurements by Tucson students. Training sessions at similar levels are continuing this year. The partnership, planning, lesson learned, and outcomes of NOAO's collaboration with the environmental center will be presented.

  8. Dark Sky Simulations: Early Data Release

    CERN Document Server

    Skillman, Samuel W; Turk, Matthew J; Wechsler, Risa H; Holz, Daniel E; Sutter, P M

    2014-01-01

    The Dark Sky Simulations are an ongoing series of cosmological N-body simulations designed to provide a quantitative and accessible model of the evolution of the large-scale Universe. Such models are essential for many aspects of the study of dark matter and dark energy, since we lack a sufficiently accurate analytic model of non-linear gravitational clustering. In July 2014, we made available to the general community our early data release, consisting of over 55 Terabytes of simulation data products, including our largest simulation to date, which used $1.07 \\times 10^{12}~(10240^3)$ particles in a volume $8h^{-1}\\mathrm{Gpc}$ across. Our simulations were performed with 2HOT, a purely tree-based adaptive N-body method, running on 200,000 processors of the Titan supercomputer, with data analysis enabled by yt. We provide an overview of the derived halo catalogs, mass function, power spectra and light cone data. We show self-consistency in the mass function and mass power spectrum at the 1% level over a range ...

  9. The Accuracy of RADIANCE Software in Modelling Overcast Sky Condition

    OpenAIRE

    Baharuddin

    2013-01-01

    A validation study of the sky models of RADIANCE simulation software against the overcast sky condition has been carried out in order to test the accuracy of sky model of RADIANCE for modeling the overcast sky condition in Hong Kong. Two sets of data have been analysed. Firstly, data collected from a set of experiments using a physical scale model. In this experiment, the illuminance of four points inside the model was measured under real sky conditions. Secondly, the RADIANCE simulation has ...

  10. Retrieval of stratospheric and tropospheric BrO profiles and columns using ground-based zenith-sky DOAS observations at Harestua, 60° N

    Directory of Open Access Journals (Sweden)

    J. A. Pyle

    2007-09-01

    Full Text Available A profiling algorithm based on the optimal estimation method is applied to ground-based zenith-sky UV-visible measurements from Harestua, Southern Norway (60° N, 11° E in order to retrieve BrO vertical profiles. The sensitivity of the zenith-sky observations to the tropospheric BrO detection is increased by using for the spectral analysis a fixed reference spectrum corresponding to clear-sky noon summer conditions. The information content and retrieval errors are characterized and it is shown that the retrieved stratospheric profiles and total columns are consistent with correlative balloon and satellite observations, respectively. Tropospheric BrO columns are derived from profiles retrieved at 80° solar zenith angle during sunrise and sunset for the 2000–2006 period. They show a marked seasonality with mean column value ranging from 1.52±0.62×1013 molec/cm² in late winter/early spring to 0.92±0.38×1013 molec/cm² in summer, which corresponds to 1.0±0.4 and 0.6±0.2 pptv, respectively, if we assume that BrO is uniformly mixed in the troposphere. These column values are also consistent with previous estimates made from balloon, satellite, and other ground-based observations. Daytime (10:30 LT tropospheric BrO columns are compared to the p-TOMCAT 3-D tropospheric chemical transport model (CTM for the 2002–2003 period. p-TOMCAT shows a good agreement with the retrieved columns except in late winter/early spring where an underestimation by the model is obtained. This finding could be explained by the non-inclusion of sea-ice bromine sources in the current version of p-TOMCAT. Therefore the model cannot reproduce the possible transport of air-masses with enhanced BrO concentration due to bromine explosion events from the polar region to Harestua. The daytime stratospheric BrO columns are compared to the SLIMCAT stratospheric 3-D-CTM. The model run used in this study, which assumes 21.2 pptv for the Bry loading (15 pptv for long

  11. Flying between sky islands: the effect of naturally fragmented habitat on butterfly population structure.

    Science.gov (United States)

    Sekar, Sandhya; Karanth, Praveen

    2013-01-01

    High elevation montane areas are called "sky islands" when they occur as a series of high mountains separated by lowland valleys. Different climatic conditions at high elevations makes sky islands a specialized type of habitat, rendering them naturally fragmented compared to more continuous habitat at lower elevations. Species in sky islands face unsuitable climate in the intervening valleys when moving from one montane area to another. The high elevation shola-grassland mosaic in the Western Ghats of southern India form one such sky island complex. The fragmented patches make this area ideal to study the effect of the spatial orientation of suitable habitat patches on population genetic structure of species found in these areas. Past studies have suggested that sky islands tend to have genetically structured populations, possibly due to reduced gene flow between montane areas. To test this hypothesis, we adopted the comparative approach. Using Amplified Fragment Length Polymorphisms, we compared population genetic structures of two closely related, similar sized butterfly species: Heteropsis oculus, a high elevation shola-grassland specialist restricted to the southern Western Ghats, and Mycalesis patnia, found more continuously distributed in lower elevations. In all analyses, as per expectation the sky island specialist H. oculus exhibited a greater degree of population genetic structure than M. patnia, implying a difference in geneflow. This difference in geneflow in turn appears to be due to the natural fragmentation of the sky island complexes. Detailed analysis of a subset of H. oculus samples from one sky island complex (the Anamalais) showed a surprising genetic break. A possible reason for this break could be unsuitable conditions of higher temperature and lower rainfall in the intervening valley region. Thus, sky island species are not only restricted by lack of habitat continuity between montane areas, but also by the nature of the intervening habitat.

  12. Dark Skies are a Universal Resource: Programs Planned for the International Year of Astronomy

    Science.gov (United States)

    Walker, Constance E.; US IYA Dark Skies Working Group

    2008-05-01

    The dark night sky is a natural resource that is being lost by much of the world's population. This loss is a growing, serious issue that impacts not only astronomical research, but also human health, ecology, safety, economics and energy conservation. One of the themes of the US Node targeted for the International Year of Astronomy (IYA) is "Dark Skies are a Universal Resource". The goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved locally in a variety of dark skies-related events. To reach this goal, activities are being developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Teaching Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize events in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs (e.g., GLOBE at Night, "How Many Stars?” and the Great World Wide Star Count) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., The Great Switch Out, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial on lighting issues). To deliver these programs, strategic networks have been established with the ASP's Night Sky Network's astronomy clubs, Astronomy from the Ground Up's science and nature centers and the Project and Family ASTRO programs, as well as the International Dark-Sky Association, GLOBE and the Astronomical League, among others. The poster presentation will outline the activities being developed, the plans for funding, implementation, marketing and the connections to the global cornerstone IYA project, "Dark Skies Awareness".

  13. Sky-View Factor as a Relief Visualization Technique

    Directory of Open Access Journals (Sweden)

    Žiga Kokalj

    2011-02-01

    Full Text Available Remote sensing has become the most important data source for the digital elevation model (DEM generation. DEM analyses can be applied in various fields and many of them require appropriate DEM visualization support. Analytical hill-shading is the most frequently used relief visualization technique. Although widely accepted, this method has two major drawbacks: identifying details in deep shades and inability to properly represent linear features lying parallel to the light beam. Several authors have tried to overcome these limitations by changing the position of the light source or by filtering. This paper proposes a new relief visualization technique based on diffuse, rather than direct, illumination. It utilizes the sky-view factor—a parameter corresponding to the portion of visible sky limited by relief. Sky-view factor can be used as a general relief visualization technique to show relief characteristics. In particular, we show that this visualization is a very useful tool in archaeology as it improves the recognition of small scale features from high resolution DEMs.

  14. All-sky interferometry with spherical harmonic transit telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J. Richard; Pen, Ue-Li [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Sigurdson, Kris; Sitwell, Michael [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Stebbins, Albert, E-mail: jrs65@cita.utoronto.ca [Theoretical Astrophysics Group, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

    2014-02-01

    In this paper, we describe the spherical harmonic transit telescope through the use of a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved-sky complications of traditional interferometry and so is particularly well-suited to the analysis of wide-field radio interferometers. It enables compact and computationally efficient representations of the data and its statistics, which allow new ways of approaching important problems like map-making and foreground removal. In particular, we show how it enables the use of the Karhunen-Loève transform as a highly effective foreground filter, suppressing realistic foreground residuals for our fiducial example by at least a factor 20 below the 21 cm signal, even in highly contaminated regions of the sky. This is despite the presence of the mode-mixing inherent in real-world instruments with frequency-dependent beams. We show, using Fisher forecasting, that foreground cleaning has little effect on power spectrum constraints compared to hypothetical foreground-free measurements. Beyond providing a natural real-world data analysis framework for 21 cm telescopes now under construction and future experiments, this formalism allows accurate power spectrum forecasts to be made that include the interplay of design constraints and realistic experimental systematics with 21st century 21 cm science.

  15. Advertising Citizen Science: A Trailer for the Citizen Sky Project

    Science.gov (United States)

    Wyatt, Ryan; Price, A.

    2012-01-01

    Citizen Sky is a multi-year, NSF funded citizen science project involving the bright and mysterious variable star epsilon Aurigae. The project was conceived by the IYA 2009 working group on Research Experiences for Students, Teachers, and Citizen-Scientists. Citizen Sky goes beyond simple observing to include a major data analysis component, introducing participants to the full scientific process from background research to paper writing for a peer-reviewed journal. As a means of generating interest in the project, the California Academy of Sciences produced a six-minute "trailer” formatted for both traditional and fulldome planetariums as well as HD and web applications. This talk will review the production process for the trailer as well as the methods of distribution via planetariums, social media, and other venues_along with an update on the Citizen Sky Project as a whole. We will show how to use a small, professionally-produced planetarium trailer to help spread word on a citizen science project. We will also show preliminary results on a study about how participation level/type in the project affects science learning.

  16. All-Sky Interferometry with Spherical Harmonic Transit Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J.Richard [Canadian Inst. Theor. Astrophys.; Sigurdson, Kris [British Columbia U.; Pen, Ue-Li [Canadian Inst. Theor. Astrophys.; Stebbins, Albert [Fermilab; Sitwell, Michael [British Columbia U.

    2013-02-01

    In this paper we describe the spherical harmonic transit telescope, a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved sky complications of traditional interferometry and so is particularly well suited to the analysis of wide-field radio interferometers. It enables compact and computationally efficient representations of the data and its statistics that allow new ways of approaching important problems like map-making and foreground removal. In particular, we show how it enables the use of the Karhunen-Loeve transform as a highly effective foreground filter, suppressing realistic foreground residuals for our fiducial example by at least a factor twenty below the 21cm signal even in highly contaminated regions of the sky. This is despite the presence of the angle-frequency mode mixing inherent in real-world instruments with frequency-dependent beams. We show, using Fisher forecasting, that foreground cleaning has little effect on power spectrum constraints compared to hypothetical foreground-free measurements. Beyond providing a natural real-world data analysis framework for 21cm telescopes now under construction and future experiments, this formalism allows accurate power spectrum forecasts to be made that include the interplay of design constraints and realistic experimental systematics with twenty-first century 21cm science.

  17. The night sky companion a yearly guide to sky-watching 2008-2009

    CERN Document Server

    Plotner, Tammy

    2007-01-01

    The Night Sky Companion is a comprehensive guide to what can be explored in the heavens on a nightly basis. Designed to appeal to readers at all skill levels, it provides a digest for sky watchers interested in all types of astronomical information.

  18. yourSky: Custom Sky-Image Mosaics via the Internet

    Science.gov (United States)

    Jacob, Joseph

    2003-01-01

    yourSky (http://yourSky.jpl.nasa.gov) is a computer program that supplies custom astronomical image mosaics of sky regions specified by requesters using client computers connected to the Internet. [yourSky is an upgraded version of the software reported in Software for Generating Mosaics of Astronomical Images (NPO-21121), NASA Tech Briefs, Vol. 25, No. 4 (April 2001), page 16a.] A requester no longer has to engage in the tedious process of determining what subset of images is needed, nor even to know how the images are indexed in image archives. Instead, in response to a requester s specification of the size and location of the sky area, (and optionally of the desired set and type of data, resolution, coordinate system, projection, and image format), yourSky automatically retrieves the component image data from archives totaling tens of terabytes stored on computer tape and disk drives at multiple sites and assembles the component images into a mosaic image by use of a high-performance parallel code. yourSky runs on the server computer where the mosaics are assembled. Because yourSky includes a Web-interface component, no special client software is needed: ordinary Web browser software is sufficient.

  19. ASEAN open skies and the implications for airport development strategy in Malaysia

    OpenAIRE

    Tham, Siew Yean

    2008-01-01

    Open Skies, in general, refers to the liberalization of aviation markets that can be pursued on a bilateral, regional, or multilateral basis. At the Association of Southeast Asian Nations (ASEAN) level, liberalization of airfreight and passenger services is targeted by December 2008. This paper seeks to examine the implication of open skies in ASEAN on the airport development strategy in Malaysia. The findings show that although Malaysia has invested substantially in overall infrastructure de...

  20. ASEAN Open Skies and Its Implications on Airport Development Strategy in Malaysia

    OpenAIRE

    Siew Yean Tham

    2008-01-01

    This paper seeks to examine the implication of open skies in ASEAN on the airport development strategy in Malaysia. "Open Skies," in general, refers to the liberalization of aviation markets that can be pursued on a bilateral, regional, or multilateral basis. The findings show that although Malaysia has invested substantially in overall infrastructure development, including airports, other member countries within ASEAN, notably Singapore and Thailand, have also followed a similar investment-i...

  1. Applications of SKY in cancer cytogenetics.

    Science.gov (United States)

    Bayani, Jane M; Squire, Jeremy A

    2002-01-01

    Clinical and cancer cytogenetics is a rapidly evolving discipline. The past decade has seen a dramatic change in molecular biology and fluorescence microscopy. The use of fluorescence in situ hybridization (FISH) technologies has enabled the rapid analysis of cytogenetic specimens as an adjunct to classical cytogenetic analysis. Spectral karyotyping (SKY) is a 24-color, multi-chromosomal painting assay that allows the visualization of all human chromosomes in one experiment. The ability for SKY analysis to detect equivocal or complex chromosomal rearrangements, as well as to identify the chromosomal origins of marker chromosomes and other extra-chromosomal structures, makes this a highly sensitive and valuable tool for identifying recurrent chromosomal aberrations. The SKY has been applied to various tumor groups including hematological malignancies, sarcomas, carcinomas and brain tumors, with the intent of identifying specific chromosomal abnormalities that may provide insight to the genes involved in the disease process as well as identifying recurrent cytogenetic markers for clinical diagnosis and prognostic assessment. The SKY has also been applied for the mouse genome, enabling investigators to extrapolate information from mouse models of cancer to their human counterparts. This review will address the advances that SKY has facilitated in the field of cancer cytogenetics, as well as its variety of application in the cancer research laboratories.

  2. The SCUBA-2 "All-Sky" Survey

    CERN Document Server

    Thompson, M A; Jenness, T; Scott, D; Ashdown, M; Brunt, C; Butner, H; Chapin, E; Chrysostomou, A C; Clark, J S; Clements, D; Collett, J L; Coppin, K; Coulson, I M; Dent, W R F; Economou, F; Evans, A; Friberg, P; Fuller, G A; Gibb, A G; Greaves, J; Hatchell, J; Holland, W S; Hudson, M; Ivison, R J; Jaffe, A; Joncas, G; Jones, H R A; Knapen, J H; Leech, J; Mann, R; Matthews, H E; Moore, T J T; Mortier, A; Negrello, M; Nutter, D; Pestalozzi, M P; Pope, A; Richer, J; Shipman, R; Urquhart, J S; Vaccari, M; Van Waerbeke, L; Viti, S; Weferling, B; White, G J; Wouterloot, J; Zhu, M

    2007-01-01

    The sub-millimetre wavelength regime is perhaps the most poorly explored over large areas of the sky, despite the considerable effort that has been expended in making deep maps over small regions. As a consequence the properties of the sub-millimetre sky as a whole, and of rare bright objects in particular, remains largely unknown. Here we describe a forthcoming survey (the SCUBA-2 ``All-Sky'' Survey, or SASSy) designed to address this issue by making a large-area map of approximately one-fifth of the sky visible from the JCMT (4800 square degrees) down to a 1 sigma noise level of 30 mJy/beam. This map forms the pilot for a much larger survey, which will potentially map the remaining sky visible from the JCMT, with the region also visible to ALMA as a priority. SASSy has been awarded 500 hours for the 4800 square degree pilot phase and will commence after the commissioning of SCUBA-2, expected in early 2008.

  3. Automatic cloud classification of whole sky images

    Directory of Open Access Journals (Sweden)

    A. Heinle

    2010-05-01

    Full Text Available The recently increasing development of whole sky imagers enables temporal and spatial high-resolution sky observations. One application already performed in most cases is the estimation of fractional sky cover. A distinction between different cloud types, however, is still in progress. Here, an automatic cloud classification algorithm is presented, based on a set of mainly statistical features describing the color as well as the texture of an image. The k-nearest-neighbour classifier is used due to its high performance in solving complex issues, simplicity of implementation and low computational complexity. Seven different sky conditions are distinguished: high thin clouds (cirrus and cirrostratus, high patched cumuliform clouds (cirrocumulus and altocumulus, stratocumulus clouds, low cumuliform clouds, thick clouds (cumulonimbus and nimbostratus, stratiform clouds and clear sky. Based on the Leave-One-Out Cross-Validation the algorithm achieves an accuracy of about 97%. In addition, a test run of random images is presented, still outperforming previous algorithms by yielding a success rate of about 75%, or up to 88% if only "serious" errors with respect to radiation impact are considered. Reasons for the decrement in accuracy are discussed, and ideas to further improve the classification results, especially in problematic cases, are investigated.

  4. VHF radar observations of the dip equatorial E-region during sunset in the Brazilian sector

    Directory of Open Access Journals (Sweden)

    C. M. Denardini

    2006-07-01

    Full Text Available Using the RESCO 50 MHz backscatter radar (2.33° S, 44.2° W, DIP: –0.5, at São Luís, Brazil, we obtained Range Time Intensity (RTI maps covering the equatorial electrojet heights during daytime and evening. These maps revealed a scattering region at an altitude of about 108 km during the sunset period. The type of 3-m irregularity region we present here has not been reported before in the literature, to our knowledge. It was mainly observed around the Southern Hemisphere summer-solstice period, under quiet magnetic activity condition. The occurrence of this echo region coincides in local time with the maximum intensity of an evening pre-reversal eastward electric field of the ionospheric F-region. A tentative explanation is proposed here in terms of the theory of the divergence of the equatorial electrojet (EEJ current in the evening ionosphere presented by Haerendel and Eccles (1992, to explain the partial contribution of the divergence to the development of the pre-reversal electric field. The theory predicts an enhanced zonal electric field and hence a vertical electric field below 300 km as a consequence of the EEJ divergence in the evening. The experimental results of the enhanced echoes from the higher heights of the EEJ region seem to provide evidence that the divergence of the EEJ current can indeed be the driver of the observed scattering region.

  5. Negative ions in the auroral mesosphere during a PCA event around sunset

    Directory of Open Access Journals (Sweden)

    C. F. del Pozo

    Full Text Available This is a study of the negative ion chemistry in the mesosphere above Tromsø using a number of EISCAT observations of high energy proton precipitation events during the last solar maximum, and in particular around sunset on 23 October, 1989. In these conditions it is possible to look at the relative importance of the various photodetachment and photodissociation processes controlling the concentration of negative ions. The data analysed are from several UHF GEN11 determinations of the ion-plasma ACF together with the pseudo zero-lag estimate of the `raw' electron density, at heights between 55 km and 85 km, at less than 1 km resolution. The power profiles from the UHF are combined with the 55-ion Sodankylä model to obtain consistent estimates of the electron density, the negative ion concentrations, and the average ion mass with height. The neutral concentrations and ion temperature are given by the MSIS90 model. These parameters are then used to compare the calculated widths of the ion-line with the GEN11 determinations. The ion-line spectrum gives information on the effects of negative ions below 70 km where they are dominant; the spectral width is almost a direct measure of the relative abundance of negative ions.

    Key words. Ionosphere (auroral ionosphere; ion chemistry and composition; particle precipitation.

  6. Adsorption of sunset yellow FCF from aqueous solution by chitosan-modified diatomite.

    Science.gov (United States)

    Zhang, Y Z; Li, J; Li, W J; Li, Y

    2015-01-01

    Sunset yellow (SY) FCF is a hazardous azo dye pollutant found in food processing effluent. This study investigates the use of diatomaceous earth with chitosan (DE@C) as a modified adsorbent for the removal of SY from wastewater. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of SY. The obtained N2 adsorption-desorption isotherm values accord well with IUPAC type II. Our calculations determined a surface area of 69.68 m2 g(-1) for DE@C and an average pore diameter of 4.85 nm. Using response surface methodology, optimized conditions of process variables for dye adsorption were achieved. For the adsorption of SY onto DE@C, this study establishes mathematical models for the optimization of pH, contact time and initial dye concentration. Contact time plays a greater role in the adsorption process than either pH or initial dye concentration. According to the adjusted correlation coefficient (adj-R2>0.97), the models used here are suitable for illustration of the adsorption process. Theoretical experimental conditions included a pH of 2.40, initial dye concentration of 113 mg L(-1) and 30.37 minutes of contact time. Experimental values for the adsorption rate (92.54%) were close to the values predicted by the models (95.29%).

  7. Phase behavior of chromonic liquid crystal mixtures of Sunset Yellow and Disodium Cromoglycate

    Science.gov (United States)

    Yamaguchi, Akihiro; Smith, Gregory; Yi, Youngwoo; Xu, Charles; Biffi, Silvia; Serra, Francesca; Bellini, Tommaso; Clark, Noel

    2014-03-01

    Chromonic liquid crystals (CLCs) are formed when planar molecules dissolved in water stack into rod-like aggregates that can order as liquid crystals. Isotropic, nematic, and M-phases can be observed depending on the degree of molecular orientational and positional order by variation of the CLC concentration. We focused on mixtures of two well-known CLCs, Sunset Yellow, a food dye, and disodium cromoglycate (DSCG), an asthma medication. In order to study the phase behaviors of these mixtures, we observed their textures in glass cells and capillaries using polarized light microscopy. We report here a ternary phase diagram describing the complete phase behavior of the CLC mixtures. We observed a variety of phase behaviors depending on species ratio and concentration. In the isotropic phase, no clear phase separation of the two dyes was observed, while separation did occur in many nematic and M-phase combinations. We will also describe phase observations made using a light spectroscopy and bulk centrifugal partitioning. Grant support: NSF DMR 1207606 and NSF MRSEC DMR-0820579.

  8. Sunset decay of the convective turbulence with Large-Eddy Simulation under realistic conditions

    Science.gov (United States)

    Rizza, U.; Miglietta, M. M.; Degrazia, G. A.; Acevedo, O. C.; Marques Filho, E. P.

    2013-10-01

    Large-Eddy Simulation is performed for a single day from the Cooperative Atmosphere-Surface Exchange Study (CASES-99) field program. This study investigates an observed case of evening transition boundary layer over land. Parameters of the ambient atmosphere in the LES-decay studies conducted so far were typically prescribed in an idealized form. To provide suitable data under the wide range of the PBL weather conditions, the LES should be able to adequately reproduce the PBL turbulence dynamics including-if possible-baroclinicity, radiation, large scale advection and not only be related to a decreasing surface heating. In addition LES-decay studies usually assume that the sensible heat flux decreases instantaneously or with a very short time scale. The main purpose of this investigation is to study the decay of boundary-layer average turbulent kinetic energy at sunset with Large-Eddy Simulation that is forced with realistic environment conditions. This allows investigating the Turbulent Kinetic Energy decay over the realistic time scale that is observed in the atmosphere. During the intermediate and last stage of decay of the boundary-layer average Turbulent Kinetic Energy the exponents of the decay power law t go from 2 to 6, as evidenced by experimental results and recent analytical modeling in the surface layer.

  9. Simultaneous determination of Sunset yellow and Tartrazine in soft drinks using gold nanoparticles carbon paste electrode.

    Science.gov (United States)

    Ghoreishi, Sayed Mehdi; Behpour, Mohsen; Golestaneh, Mahshid

    2012-05-01

    The monitoring of synthetic dyes in foods is very important due to their potential harmfulness to human beings. Herein, a carbon-paste electrode (CPE) that is chemically modified with gold nanoparticles (nAu) was fabricated and used for the determination of Sunset yellow (SY) and Tartrazine (Tz). Cyclic and differential pulse voltammetry (CV and DPV) results revealed two well-resolved anodic peaks for SY and Tz with remarkably increase in oxidation signals of these colourants. Based on this, a novel electrochemical method was developed for the simultaneous determination of SY and Tz. High sensitivity and selectivity, sub-micromolar detection limit, high reproducibility and regeneration of the electrode surface by simple polishing make the nAu-CPE electrode very suitable for the determination of SY and Tz in commercially available soft drinks. The detection limits was 3.0×10(-8) and 2.0×10(-9)moll(-1) for SY and Tz, respectively, which are remarkably lower than those reported previously for SY and Tz using other modified electrodes.

  10. Odin/OSIRIS observations of stratospheric NO3 through sunrise and sunset

    Directory of Open Access Journals (Sweden)

    C. S. Haley

    2008-09-01

    Full Text Available The nitrate radical (NO3 has been detected in visible limb-scattered spectra measured by the Optical Spectrograph and InfraRed Imager System (OSIRIS on-board the Odin satellite when observing at large solar zenith angles (91–97°. Apparent slant column densities of NO3 at tangent heights between 10 and 45 km are derived via spectral fitting in the 610–680 nm window. Using observations from multiple scans spanning solar zenith angles of 91–97°, the rapid evolution of NO3 through sunrise and sunset can be traced. Slant column densities are found to be generally consistent with those simulated using a radiative transfer model with coupled photochemistry. In addition, a strong dependence of NO3 with temperature is observed. These results indicate that our current knowledge of NO3 photochemistry is generally consistent with OSIRIS observations to within the limitations of the radiative transfer modeling. Furthermore, they reveal that OSIRIS possesses signal-to-noise sufficient to make useful measurements of scattered sunlight out to solar zenith angles of 91–97° and suggest the possibility of retrieving profile information for NO3 and other species at large solar zenith angles.

  11. Odin/OSIRIS observations of stratospheric NO3 through sunrise and sunset

    Directory of Open Access Journals (Sweden)

    C. S. Haley

    2008-03-01

    Full Text Available The nitrate radical (NO3 has been detected in visible limb-scattered spectra measured by the Optical Spectrograph and InfraRed Imager System (OSIRIS on-board the Odin satellite when observing at large solar zenith angles (91–97°. Apparent slant column densities of NO3 at tangent heights between 10 and 45 km are derived via spectral fitting in the 590–680 nm window. Using observations from multiple scans spanning solar zenith angles of 91–97°, the rapid evolution of NO3 through sunrise and sunset can be traced. Slant column densities are found to be consistent with those simulated using a radiative transfer model with coupled photochemistry. In addition, a strong dependence of NO3 with temperature is observed. These results indicate that OSIRIS possesses signal-to-noise sufficient to make useful measurements of scattered sunlight out to solar zenith angles of 96–97° and suggests the possibility of retrieving profile information for NO3 and other species at large solar zenith angles.

  12. Behavior of foF2 and hmF2 after sunset

    Science.gov (United States)

    Danilov, A. D.; Vanina-Dart, L. B.

    2010-12-01

    The time behavior of the foF2 and hmF2 values at the time moment T(ss + 2 h) 2 h after sunset is considered. It is assumed that at this moment, the horizontal winds in the thermosphere in the strongest way influence hmF2 and, therefore, foF2. It is found that a fairly well pronounced and statistically significant change (trend) is observed for the foF2(ss + 2)/ foF2(14) ratio, the sign of the change being different for different stations and even different seasons at the same station. A similar picture is obtained for the value of hmF2(ss + 2). It is shown that a positive correlation between the trends of these two values is observed. This confirms the initial concept of the paper that the foF2 and hmF2 trends are caused by long-term trends in the thermospheric dynamics.

  13. SPHEREx: An All-Sky Spectral Survey

    CERN Document Server

    Doré, Olivier; Capak, Peter; de Putter, Roland; Eifler, Tim; Hirata, Chris; Korngut, Phil; Krause, Elisabeth; Masters, Daniel; Raccanelli, Alvise; Zemcov, Mike; Cooray, Asantha; Flagey, Nicolas; Gong, Yan; Katti, Raj; Melnick, Gary; Mennesson, Bertrand; Unwin, Steve; Viero, Marco; Werner, Mike; Ashby, Matthew; Habib, Salman; Heitmann, Katrin; Lee, Dae-Hee; Jeong, Woong-Seob; Mauskopf, Phil; Nguyen, Hien; Öberg, Karin; Smith, Roger; Song, Yong-Seon; Tolls, Volker; Venumadhav, Tejaswi

    2014-01-01

    SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) is a proposed all-sky spectroscopic survey satellite designed to address all three science goals in NASA's Astrophysics Division: probe the origin and destiny of our Universe; explore whether planets around other stars could harbor life; and explore the origin and evolution of galaxies. SPHEREx will scan a series of Linear Variable Filters systematically across the entire sky. The SPHEREx data-set will contain R=40 spectra spanning the near infrared (0.75$\\mu$m$<\\lambda<$ 4.83$\\mu$m) for every 6.2 arcsecond pixel over the the entire-sky. In this paper, we detail the extra-galactic and cosmological studies SPHEREx will enable and present detailed systematic effect evaluations.

  14. On-sky MOAO performance evaluation of RAVEN

    Science.gov (United States)

    Ono, Y. H.; Correia, Carlos M.; Lardière, O.; Andersen, D. R.; Oya, S.; Akiyama, M.; Gamroth, D.; Jackson, K.; Martin, O.; Bradley, C.

    2016-07-01

    This paper presents the AO performance we got on-sky with RAVEN, a Multi-Object Adaptive Optics (MOAO) technical and science demonstrator installed and tested at the Subaru telescope. We report Ensquared-Energy (EE) and Full Width at Half Maximum (FWHM) measured from science images on Subaru's IRCS taken during all of the on-sky observing runs. We show these metrics as function of different AO modes and atmospheric conditions for two asterisms of natural guide stars. The performances of the MOAO and Ground-Layer AO (GLAO) modes are between the classical Single-Conjugate AO (SCAO) and seeing-limited modes. We achieve the EE of 30% in H-band with the MOAO correction, which is a science requirement for RAVEN. The MOAO provides sightly better performance than the GLAO mode in both asterisms. One of the reasons which cause this small difference between the MOAO and GLAO modes may be the strong GL contribution. Also, the performance of the MOAO modes is affected by the accuracy of the on-sky turbulence profiling by the SLOpe Detection And Ranging (SLODAR) method.

  15. Sky observation and mythology: paths to an astronomical culture

    Science.gov (United States)

    Alencar, Victor Alves

    2011-06-01

    The teaching and the popularization of Astronomy, nowadays, suffers from the absence of attractiveness. It's, somehow, consensual that the most efficient approach to attract the general public or even an uninterested student to the Astronomy is the sky observation. With the help of instruments like telescopes or binoculars, the observation of aesthetical impressive objects such as galactic clusters, approaching planets and many others may have a great impact upon those people. We have been executing an efficient and attractive didactic method which has been evaluated permanently for more than two years and has shown great efficiency that consists in the utilization of legends and myths from different cultures (including Brazilian Indians myths, in an etnoastronomical approach) about the constellations and their dispositions in the sky. The objective of this panel is to show the efficiency of the method and some of its teaching routines always beginning with myths or legends involving a great number of constellations (using, preferentially, most of the watchable sky in a certain time of year), using asterisms for identification and then following to a certain constellation from which it is possible to extract the information required for the studied subject.

  16. Measurement and analysis of sky background spectra in passive ranging

    Science.gov (United States)

    Yu, Zhang; Liu, Bingqi; Yu, Hao; Li, Xiaoming; Yan, Zongqun; Hua, Wenshen; Shi, Yunsheng; Chen, Yichao

    2015-10-01

    Experimental program is designed to analyze the radiation and absorption characteristic of the sky background at near-infrared Oxygen A absorption band of passive ranging based on Oxygen spectral absorption; an acousto-optic tunable hyper spectral imaging spectrometer is used as the measuring device. Under the condition of sunny, cloudy, and snowy weather, the sky background spectral distribution is collected using the acousto-optic tunable hyper spectral imaging spectrometer. Then the Oxygen absorption rate is calculated according to the principle of Oxygen spectrum absorption passive ranging. The measurement result shows: absorption lines exist in the sky background spectral distribution at the Oxygen A absorption band, and the absorption rates are different at different weather conditions. The Oxygen absorption rates are the biggest under snowy weather, bigger under cloudy weather, and the smallest under sunny weather. The general change pattern of Oxygen absorption rate under different weather conditions is obtained and the result has laid solid foundation for suppressing the interference of the background and extracting target spectral accurately in subsequent passive ranging researching.

  17. Second ROSAT all-sky survey (2RXS) source catalogue

    CERN Document Server

    Boller, Th; Truemper, J; Haberl, F; Voges, W; Nandra, K

    2016-01-01

    We present the second ROSAT all-sky survey source catalogue, hereafter referred to as the 2RXS catalogue. This is the second publicly released ROSAT catalogue of point-like sources obtained from the ROSAT all-sky survey (RASS) observations performed with the PSPC between June 1990 and August 1991, and is an extended and revised version of the bright and faint source catalogues. We used the latest version of the RASS processing to produce overlapping X-ray images of 6.4x6.4 degrees sky regions. To create a source catalogue, a likelihood-based detection algorithm was applied to these, which accounts for the PSF across the PSPC field of view. Improvements in the background determination compared to 1RXS were also implemented. We obtained about 135,000 X-ray detections in the 0.1-2.4 keV energy band down to a likelihood threshold of 6.5. Our simulations show that the expected spurious content of the catalogue is a strong function of detection likelihood, and the full catalogue is expected to contain about 30% spu...

  18. Feasibility of polarized all-sky imaging for aerosol characterization

    Directory of Open Access Journals (Sweden)

    A. Kreuter

    2013-07-01

    Full Text Available In this study, we investigate the method of polarized all-sky imaging with respect to aerosol characterization. As a technical frame work for image processing and analysis, we propose Zernike polynomials to decompose the relative Stokes parameter distributions. This defines a suitable and efficient feature vector which is also appealing because it is independent of calibration, circumvents overexposure problems and is robust against pixel noise. We model the polarized radiances of realistic aerosol scenarios and construct the feature vector space of the key aerosol types in terms of the first two principal components describing the maximal variances. We show that, using this representation, aerosol types can be clearly distinguished with respect to fine and coarse mode dominated size distribution and index of refraction. We further investigate the individual influences of varying aerosol properties and solar zenith angle. This suggests that polarized all-sky imaging may improve aerosol characterization in combination with sky scanning radiometers of the existing Aerosol Robotic Network (AERONET especially at low aerosol optical depths and low solar zenith angles.

  19. [The backgroud sky subtraction around [OIII] line in LAMOST QSO spectra].

    Science.gov (United States)

    Shi, Zhi-Xin; Comte, Georges; Luo, A-Li; Tu, Liang-Ping; Zhao, Yong-Heng; Wu, Fu-Chao

    2014-11-01

    At present, most sky-subtraction methods focus on the full spectrum, not the particular location, especially for the backgroud sky around [OIII] line which is very important to low redshift quasars. A new method to precisely subtract sky lines in local region is proposed in the present paper, which sloves the problem that the width of Hβ-[OIII] line is effected by the backgroud sky subtraction. The exprimental results show that, for different redshift quasars, the spectral quality has been significantly improved using our method relative to the original batch program by LAMOST. It provides a complementary solution for the small part of LAMOST spectra which are not well handled by LAMOST 2D pipeline. Meanwhile, This method has been used in searching for candidates of double-peaked Active Galactic Nuclei.

  20. Sky-view factor visualization for detection of archaeological remains

    Science.gov (United States)

    Kokalj, Žiga; Oštir, Krištof; Zakšek, Klemen

    2013-04-01

    Many archaeological remains are covered by sand or vegetation but it still possible to detect them by remote sensing techniques. One of them is airborne laser scanning that enables production of digital elevation models (DEM) of very high resolution (better than 1 m) with high relative elevation accuracy (centimetre level), even under forest. Thus, it has become well established in archaeological applications. However, effective interpretation of digital elevation models requires appropriate data visualization. Analytical relief shading is used in most cases. Although widely accepted, this method has two major drawbacks: identifying details in deep shades and inability to properly represent linear features lying parallel to the light beam. Several authors have tried to overcome these limitations by changing the position of the light source or by filtering. This contribution addresses the DEM visualization problem by sky-view factor, a visualization technique based on diffuse light that overcomes the directional problems of hill-shading. Sky-view factor is a parameter that describes the portion of visible sky limited by relief. It can be used as a general relief visualization technique to show relief characteristics. In particular, we show that this visualization is a very useful tool in archaeology. Applying the sky-view factor for visualization purposes gives advantages over other techniques because it reveals small (or large, depending on the scale of the observed phenomenon and consequential algorithm settings) relief features while preserving the perception of general topography. In the case study (DEM visualization of a fortified enclosure of Tonovcov grad in Slovenia) we show that for the archaeological purposes the sky-view factor is the optimal DEM visualization method. Its ability to consider the neighborhood context makes it an outstanding tool when compared to other visualization techniques. One can choose a large search radius and the most important

  1. Predicting UV sky for future UV missions

    Science.gov (United States)

    Safonova, M.; Mohan, R.; Sreejith, A. G.; Murthy, Jayant

    2013-02-01

    Software simulators are now widely used in all areas of science, especially in application to astronomical missions: from instrument design to mission planning, and to data interpretation. We present a simulator to model the diffuse ultraviolet sky, where the different contributors are separately calculated and added together to produce a sky image of the size specified by the instrument requirements. Each of the contributors to the background, instrumental dark current, airglow, zodiacal light and diffuse Galactic light, depends on different factors. Airglow is dependent on the time of day; zodiacal light depends on the time of year, angle from the Sun and from the ecliptic; diffuse UV emission depends on the line of sight. To provide a full description of the sky along any line of sight, we have also added stars. The UV background light can dominate in many areas of the sky and severely limit viewing directions due to overbrightness. The simulator, available as a downloadable package and as a web-based tool, can be applied to preparation of real space missions and instruments. For demonstration, we present the example use for the two near-future UV missions: UVIT instrument on the Indian Astrosat mission and a new proposed wide-field (∼1000 square degrees) transient explorer satellite.

  2. Giant Rings in the CMB Sky

    CERN Document Server

    Kovetz, Ely D; Itzhaki, Nissan

    2010-01-01

    We find a unique direction in the CMB sky around which giant rings have an anomalous mean temperature profile. This direction is in very close alignment with the afore measured anomalously large bulk flow direction. We argue that a cosmic defect seeded by a pre-inflationary particle could explain the giant rings, the large bulk flow and their alignment.

  3. Pips and spots in the microwave sky

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Gonzalez, E.; Sanz, J.L.

    1989-04-15

    An analysis is presented of some local statistical properties in the microwave sky such as mean number of hotspots over the celestial sphere, mean size of a hotspot, mean number of pips at fixed declination and 95 per cent confidence interval for the threshold of the hottest spot or pip, associated with three different experiments. (author).

  4. Sirius brightest diamond in the night sky

    CERN Document Server

    Holberg, Jay B

    2007-01-01

    This book describes why Sirius has been regarded as an important fixture of the night sky since the beginnings of history. It also examines the part that Sirius has played in how we came to achieve our current scientific understanding of stars.

  5. Why Is the Sky Dark at Night?

    Science.gov (United States)

    Stinner, Arthur

    2014-01-01

    The puzzle as to just why the sky is dark at night, given that there are so many stars, has been around at least since Newton. This article summarizes six cosmological models that have been used to attempt to give an account of this puzzle including the Copernican universe, the Newton-Halley universe, the nineteenth century "one galaxy"…

  6. Night-sky brightness monitoring in Hong Kong: a city-wide light pollution assessment.

    Science.gov (United States)

    Pun, Chun Shing Jason; So, Chu Wing

    2012-04-01

    Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light-sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe-the urban night skies (sky brightness at 15.0 mag arcsec(- 2)) are on average ~ 100 times brighter than at the darkest rural sites (20.1 mag arcsec(- 2)), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag arcsec(- 2) can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by human factors such as land utilization and population density of the observation sites, together with meteorological and/or environmental factors. Moreover, earlier night skies (at 9:30 p.m. local time) are generally brighter than later time (at 11:30 p.m.), which can be attributed to some public and commercial lightings being turned off later at night. On the other hand, no concrete relationship between the observed sky brightness and air pollutant concentrations could be established with the limited survey sampling. Results from this survey will serve as an important database for the public to assess whether new rules and regulations are necessary to control the use of outdoor lightings in Hong Kong.

  7. Self-Assembly of Lyotropic Chromonic Liquid Crystal Sunset Yellow and Effects of Ionic Additives

    Energy Technology Data Exchange (ETDEWEB)

    Park, Heung-Shik; Kang, Shin-Woong; Tortora, Luana; Nastishin, Yuriy; Finotello, Daniele; Kumar, Satyendra; Lavrentovich, Oleg D. (NSF); (Institute of Physical Optics, Ukraine); (Kent)

    2008-12-22

    Lyotropic chromonic liquid crystals (LCLCs) are formed by molecules with ionic groups at the periphery that associate into stacks through noncovalent self-assembly while in water. The very existence of the nematic (N) phase in the typical LCLC, the dye Sunset Yellow (SSY) is a puzzle, as the correlation length associated with the stacking, as measured in the X-ray experiments, is too short to explain the orientational order by the Onsager model. We propose that the aggregates can be more complex than simple rods and contain 'stacking faults' such as junctions with a shift of neighboring molecules, 3-fold junctions, etc. We study how ionic additives, such as salts of different valency and pH-altering agents, alter the N phase of SSY purified by recrystallization. The additives induce two general trends: (a) stabilization of the N phase, caused by the mono and divalent salts (such as NaCl), and evidenced by the increase of the N-to-I transition temperature and the correlation length; (b) suppression of the N phase manifested in the decrease of the N-to-I transition temperature and in separation of the N phase into a more densely packed N phase or the columnar (C) phase, coexisting with a less condensed I phase. The scenario (b) can be triggered by simply increasing pH (adding NaOH). The effects produced by tetravalent spermine fall mostly into the category (b), but the detail depends on whether this additive is in its salt form or a free base form. The base form causes changes through changes in pH and possible excluded volume effects whereas the salt form might disrupt the structure of SSY aggregates.

  8. Night-sky brightness monitoring in Hong Kong - a city-wide light pollution assessment

    CERN Document Server

    Pun, Chun Shing Jason

    2011-01-01

    Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe - the urban night-skies (sky brightness at 15.0 mag per arcsec square) are on average ~100 times brighter than at the darkest rural sites (20.1 mag per arcsec square), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag per arcsec square can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by hu...

  9. Night sky photometry and spectroscopy performed at the Vienna University Observatory

    CERN Document Server

    Puschnig, Johannes; Uttenthaler, Stefan

    2013-01-01

    We present night sky brightness measurements performed at the Vienna University Observatory and at the Leopold-Figl-Observatorium fuer Astrophysik, which is located about 35km to the southwest of Vienna. The measurements have been performed with Sky Quality Meters made by Unihedron. They cover a time span of roughly one year and have been carried out every night, yielding a night sky brightness value every 7 seconds and thus delivering a large amount of data. In this paper, the level of light pollution at the Vienna University Observatory, which ranges from 15 to 19.25 magnitudes per square arcsecond, is presented for the very first time in a systematic way. We discuss the influence of different environmental conditions on the night sky brightness and implications for human vision. We show that the circalunar rhythm of night sky brightness is extinguished at our observatory due to light pollution. Additionally, we present spectra of the night sky in Vienna, taken with a 0.8m telescope. The goal of these spect...

  10. Night sky photometry and spectroscopy performed at the Vienna University Observatory

    Science.gov (United States)

    Puschnig, Johannes; Posch, Thomas; Uttenthaler, Stefan

    2014-05-01

    We present night sky brightness measurements performed at the Vienna University Observatory and at the Leopold-Figl-Observatorium für Astrophysik, which is located about 35 km to the southwest of Vienna. The measurements have been performed with Sky Quality Meters made by Unihedron. They cover a time span of roughly one year and have been carried out every night, yielding a luminance value every 7 s and thus delivering a large amount of data. In this paper, the level of skyglow in Vienna, which ranges from 15 to 19.25 magSQM arcsec-2 is presented for the very first time in a systematic way. We discuss the influence of different environmental conditions on the night sky brightness and implications for human vision. We show that the circalunar rhythm of night sky brightness is almost extinguished at our observatory due to light pollution. Additionally, we present spectra of the night sky in Vienna, taken with a 0.8 m telescope. The goal of these spectroscopic measurements was to identify the main types of light sources and the spectral lines which cause the skyglow in Vienna. It turned out that fluorescent lamps are responsible for the strongest lines of the night sky above Vienna (e.g. lines at 546 nm and at 611 nm).

  11. The Night Sky Spectrum of Xinglong Observatory: Changes from 2004 to 2015

    CERN Document Server

    Zhang, Ji-Cheng; Yan, Jing-Zhi; Kumar, Yerra Bharat; Li, Hong-Bin; Gao, Dong-Yang; Jiang, Xiao-Jun

    2016-01-01

    We present spectroscopic measurements on the night sky of Xinglong Observatory for a period of 12 years from 2004 to 2015. The spectra were obtained on moonless clear nights using the OMR spectrograph mounted on a 2.16-m reflector with a wavelength coverage of 4000-7000A. The night sky spectrum shows the presence of emission lines from Hg I and Na I due to local artificial sources, along with the atmospheric emission lines, i.e., O I and OH molecules, indicating the existence of light pollution. We have monitored the night sky brightness during the whole night and found some decrement in the sky brightness with time, but the change is not significant. Also, we monitored the light pollution level in different azimuthal directions and found that the influence of light pollution from the direction of Beijing is stronger compared with that from the direction of Tangshan and other areas. An analysis of night sky spectra for the entire data set suggested that the zenith sky brightness of Xinglong Observatory has br...

  12. Surface-enhanced oxidation and detection of Sunset Yellow and Tartrazine using multi-walled carbon nanotubes film-modified electrode.

    Science.gov (United States)

    Zhang, Weikang; Liu, Tao; Zheng, Xiaojiang; Huang, Wensheng; Wan, Chidan

    2009-11-01

    The insoluble multi-walled carbon nanotubes (MWNT) was successfully dispersed into water in the presence of hydrophobic surfactant. After that, MWNT film-coated glassy carbon electrode (GCE) was achieved via dip-coating and evaporating water. Owing to huge surface area, high sorption capacity and subtle electronic properties, MWNT film exhibits highly efficient accumulation efficiency as well as considerable surface enhancement effects to Sunset Yellow and Tartrazine. As a result, the oxidation peak currents of Sunset Yellow and Tartrazine remarkably increase at the MWNT film-modified GCE. Based on this, a novel electrochemical method was developed for the simultaneous determination of Sunset Yellow and Tartrazine. The limits of detection are 10.0 ng mL(-1) (2.2 x 10(-8)mol L(-1)) and 0.1 microg mL(-1) (1.88 x 10(-7)mol L(-1)) for Sunset Yellow and Tartrazine. Finally, the proposed method was successfully used to detect Sunset Yellow and Tartrazine in soft drinks.

  13. Combining sky and earth: desert ants (Melophorus bagoti) show weighted integration of celestial and terrestrial cues.

    Science.gov (United States)

    Legge, Eric L G; Wystrach, Antoine; Spetch, Marcia L; Cheng, Ken

    2014-12-01

    Insects typically use celestial sources of directional information for path integration, and terrestrial panoramic information for view-based navigation. Here we set celestial and terrestrial sources of directional information in conflict for homing desert ants (Melophorus bagoti). In the first experiment, ants learned to navigate out of a round experimental arena with a distinctive artificial panorama. On crucial tests, we rotated the arena to create a conflict between the artificial panorama and celestial information. In a second experiment, ants at a feeder in their natural visually-cluttered habitat were displaced prior to their homing journey so that the dictates of path integration (feeder to nest direction) based on a celestial compass conflicted with the dictates of view-based navigation (release point to nest direction) based on the natural terrestrial panorama. In both experiments, ants generally headed in a direction intermediate to the dictates of celestial and terrestrial information. In the second experiment, the ants put more weight on the terrestrial cues when they provided better directional information. We conclude that desert ants weight and integrate the dictates of celestial and terrestrial information in determining their initial heading, even when the two directional cues are highly discrepant. © 2014. Published by The Company of Biologists Ltd.

  14. Global luminous efficacies on vertical surfaces for all sky types

    Energy Technology Data Exchange (ETDEWEB)

    Soler, A. [E.T.S. Arquitectura, Madrid (Spain). Dpto. de Fisica e Instalaciones Aplicados; Universidad Politecnico de Madrid (Spain). Facultad de Ciencias Ambientales; Robledo, L. [Universidad Politecnica de Madrid (Spain). Dpto. Sistemas Intelligentes Aplicados

    2000-02-01

    Luminous efficacies are determined at Madrid for North, South, East, West facing surfaces in two ways: by taking into account all the global illuminance and irradiance values available, and by considering data for each of three sky categories as defined from values of the sky clearness index {epsilon}' and the sky brightness index {delta}. Both methods are compared, and for {epsilon}' < 1.23 (overcast skies) the second method is found to be more accurate than the first. (author)

  15. The Flower Lake in the End of the Sky

    Institute of Scientific and Technical Information of China (English)

    RaoRao; GuangYu

    2005-01-01

    Every adventurer may have a wish to travel to the end of the sky. In their minds, the end of the sky not only means a long journey and being away from urban hurly-burly, but also symbolizes the most beautiful place. The Flower Lake is such a place in the end of the sky.

  16. A photometric model for predicting the sky glow of greenhouses

    NARCIS (Netherlands)

    Alferdinck, J.W.A.M.; Janssen, E.G.O.N.; Zonneveldt, L.; Ruigrok, J.

    2006-01-01

    many greenhouses use artificial light to grow plants. Part of this light escapes, scatters in the sky and causes sky glow. Residents in the vicinity complain about the absence of natural darkness. A light scatter model is developed in order to quantify the dose of the sky glow. The luminance of the

  17. The 'Starry Sky' in Tuberculoma

    Directory of Open Access Journals (Sweden)

    Shinjan Patra, Partha Pratim Chakraborty, Gouranga Santra

    2017-12-01

    Full Text Available A 27 year old lady was admitted with high-grade fever, severe headache along with dry-cough and she was being treated for neurocysticercosis on basis of ‘starry sky’ pattern on her magnetic resonance imaging (MRI of brain. She was found to have hemorrhagic and exudative pleural effusion (Light’s criteria with lymphocytic pleocytosis, adenosine deaminase (ADA value was 105.2 U/L, cartridge based nucleic acid amplification test (CBNAAT for tubercular bacilli from fluid came positive and Mantoux test was positive also. With a strong suspicion of tuberculosis the patient was put on anti-tubercular therapy along with anticonvulsants and oral steroid. Interestingly she showed remarkable permanent improvement.

  18. All Sky Survey Mission Observing Scenario Strategy

    CERN Document Server

    Spangelo, Sara C; Unwin, Stephen C; Bock, Jamie J

    2014-01-01

    This paper develops a general observing strategy for missions performing all-sky surveys, where a single spacecraft maps the celestial sphere subject to realistic constraints. The strategy is flexible such that targeted observations and variable coverage requirements can be achieved. This paper focuses on missions operating in Low Earth Orbit, where the thermal and stray-light constraints due to the Sun, Earth, and Moon result in interacting and dynamic constraints. The approach is applicable to broader mission classes, such as those that operate in different orbits or that survey the Earth. First, the instrument and spacecraft configuration is optimized to enable visibility of the targeted observations throughout the year. Second, a constraint-based high-level strategy is presented for scheduling throughout the year subject to a simplified subset of the constraints. Third, a heuristic-based scheduling algorithm is developed to assign the all-sky observations over short planning horizons. The constraint-based...

  19. Cool Technologies for the "Sky Train"

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The first train from Beijing to Tibet set out on its maiden voyage along the world's highest railway on July 1, 2006. With most of the new 1,110-kilometer track from Golmud in Qinghai to Lhasa at altitudes above 4,000 meters, the train, which is known as the "sky train" by local people, crosses more than 550 kilometers of permafrost, posing a major challenge to the railway's design and construction.

  20. 全新土星Saturn Sky

    Institute of Scientific and Technical Information of China (English)

    张琼

    2002-01-01

    @@ 大多数概念车都为测试公众的反应而设计,而全新敞蓬概念车土星天家(Saturn SKY)却是为了迎合青年人的鼓掌好而诞生,满足他们自己和朋友寻找一片乐土的迫切愿望.

  1. Aquarius L-Band Radiometers Calibration Using Cold Sky Observations

    Science.gov (United States)

    Dinnat, Emmanuel P.; Le Vine, David M.; Piepmeier, Jeffrey R.; Brown, Shannon T.; Hong, Liang

    2015-01-01

    An important element in the calibration plan for the Aquarius radiometers is to look at the cold sky. This involves rotating the satellite 180 degrees from its nominal Earth viewing configuration to point the main beams at the celestial sky. At L-band, the cold sky provides a stable, well-characterized scene to be used as a calibration reference. This paper describes the cold sky calibration for Aquarius and how it is used as part of the absolute calibration. Cold sky observations helped establish the radiometer bias, by correcting for an error in the spillover lobe of the antenna pattern, and monitor the long-term radiometer drift.

  2. An All Sky Transmission Monitor: ASTMON

    CERN Document Server

    Aceituno, J; Aceituno, F J; Galadi-Enriquez, D; Negro, J J; Soriguer, R C; Gomez, G Sanchez

    2011-01-01

    We present here the All Sky Transmission MONitor (ASTMON), designed to perform a continuous monitoring of the surface brightness of the complete night-sky in several bands. The data acquired are used to derive, in addition, a subsequent map of the multiband atmospheric extinction at any location in the sky, and a map of the cloud coverage. The instrument has been manufactured to afford extreme weather conditions, and remain operative. Designed to be fully robotic, it is ideal to be installed outdoors, as a permanent monitoring station. The preliminary results based on two of the currently operative units (at Do\\~nana National Park - Huelva- and at the Calar Alto Observatory - Almer\\'ia -, in Spain), are presented here. The parameters derived using ASTMON are in good agreement with previously reported ones, what illustrates the validity of the design and the accuracy of the manufacturing. The information provided by this instrument will be presented in forthcoming articles, once we have accumulated a statistic...

  3. Modelling UV sky for future UV missions

    Science.gov (United States)

    Sreejith, A. G.; Safanova, M.; Mohan, R.; Murthy, Jayant

    Software simulators are now widely used in all areas of science, especially in application to astronomical missions: from instrument design to mission planning, and to data interpretation. We present a simulator to model the diffuse ultraviolet sky, where the different contributors are separately calculated and added together to produce a sky image of the size specified by the instrument requirements. Each of the contributors to the background, instrumental dark current, airglow, zodiacal light and diffuse galactic light, is dependent on various factors. Airglow is dependent on the time of day, zodiacal light on the time of year, angle from the Sun and from the ecliptic, and diffuse UV emission depends on the look direction. To provide a full description of any line of sight, we have also added stars. The diffuse UV background light can dominate in many areas of the sky and severely impact space telescopes viewing directions due to over brightness. The simulator, available as a downloadable package and as a simple web-based tool, can be applied to separate missions and instruments. For demonstration, we present the example used for two UV missions: the UVIT instrument on the Indian ASTROSAT mission to be launched in the next year and a prospective wide-field mission to search for transients in the UV.

  4. Cosmology with all-sky surveys

    CERN Document Server

    Bilicki, Maciej

    2015-01-01

    Various aspects of cosmology require comprehensive all-sky mapping of the cosmic web to considerable depths. In order to probe the whole extragalactic sky beyond 100 Mpc, one must draw on multiwavelength datasets and state-of-the-art photometric redshift techniques. Here I summarize our dedicated program that employs the largest photometric all-sky surveys -- 2MASS, WISE and SuperCOSMOS -- to obtain accurate redshift estimates of millions of galaxies. The first outcome of these efforts -- the 2MASS Photometric Redshift catalog (2MPZ) -- was publicly released in 2013 and includes almost 1 million galaxies with a median redshift of z~0.1. I discuss how this catalog was constructed and how it is being used for various cosmological tests. I also present how combining the WISE mid-infrared survey with SuperCOSMOS optical data allowed us to push to depths over 1 Gpc on unprecedented angular scales. These photometric redshift samples, with about 20 million sources in total, provide access to volumes large enough to ...

  5. Cosmology with all-sky surveys

    Science.gov (United States)

    Bilicki, Maciej

    2016-06-01

    Various aspects of cosmology require comprehensive all-sky mapping of the cosmic web to considerable depths. In order to probe the whole extragalactic sky beyond 100 Mpc, one must draw on multiwavelength datasets and state-of-the-art photometric redshift techniques. Here I summarize our dedicated program that employs the largest photometric all-sky surveys - 2MASS, WISE and SuperCOSMOS - to obtain accurate redshift estimates of millions of galaxies. The first outcome of these efforts - the 2MASS Photometric Redshift catalog (2MPZ) - was publicly released in 2013 and includes almost 1 million galaxies with a median redshift of z˜0.1. I discuss how this catalog was constructed and how it is being used for various cosmological tests. I also present how combining the WISE mid-infrared survey with SuperCOSMOS optical data allowed us to push to depths over 1 Gpc on unprecedented angular scales. These photometric redshift samples, with about 20 million sources in total, provide access to volumes large enough to study observationally the Copernican Principle of universal homogeneity and isotropy, as well as to probe various aspects of dark energy and dark matter through cross-correlations with other data such as the cosmic microwave or gamma-ray backgrounds. Last but not least, they constitute a test-bed for forthcoming wide-angle multi-million galaxy samples expected from such instruments as the SKA, Euclid, or LSST.

  6. Starry sky hepatic ultrasonographic pattern in horses.

    Science.gov (United States)

    Carlson, Kelly L; Chaffin, M Keith; Corapi, Wayne V; Snowden, Karen F; Schmitz, David G

    2011-01-01

    The starry sky hepatic pattern is an unusual ultrasonographic appearance of equine liver characterized by numerous small, hyperechoic foci, some of which cast an acoustic shadow, distributed randomly throughout the hepatic parenchyma. Our objectives were to describe the signalment, clinical signs, clinicopathological findings, primary disease process, and ultrasonographic findings of horses with this ultrasonographic pattern, as well as determine the associated gross and histologic changes. The starry sky pattern was identified in 18 adult horses of mixed gender and breed. The horses had various clinical signs, with weight loss and anorexia reported most commonly. Liver size and parenchymal echogenicity were normal in most horses. The hyperechoic foci frequently caused acoustic shadowing. Biliary dilation was noted rarely. The ultrasonographic pattern was the result of numerous fibrosing hepatic granulomas in all horses evaluated histologically. γ-Glutamyltransferase was the most commonly elevated hepatic enzyme, though it was increased in fewer than half the horses. Fifteen horses had an additional disease that was identified as the apparent cause of clinical signs. Three horses had primary hepatic disease while 12 had diseases of other body systems. Therefore, the starry sky ultrasonographic pattern is likely incidental in most horses and not clinically significant. Improved recognition of this pattern and further investigation of affected horses may help refine the etiology and clinical significance of the granulomas.

  7. First Science Verification of the VLA Sky Survey Pilot

    Science.gov (United States)

    Cavanaugh, Amy

    2017-01-01

    My research involved analyzing test images by Steve Myers for the upcoming VLA Sky Survey. This survey will cover the entire sky visible from the VLA site in S band (2-4 GHz). The VLA will be in B configuration for the survey, as it was when the test images were produced, meaning a resolution of approximately 2.5 arcseconds. Conducted using On-the-Fly mode, the survey will have a speed of approximately 20 deg2 hr-1 (including overhead). New Python imaging scripts are being developed and improved to process the VLASS images. My research consisted of comparing a continuum test image over S band (from the new imaging scripts) to two previous images of the same region of the sky (from the CNSS and FIRST surveys), as well as comparing the continuum image to single spectral windows (from the new imaging scripts and of the same sky region). By comparing our continuum test image to images from CNSS and FIRST, we tested on-the-Fly mode and the imaging script used to produce our images. Another goal was to test whether individual spectral windows could be used in combination to calculate spectral indices close to those produced over S band (based only on our continuum image). Our continuum image contained 64 sources as opposed to the 99 sources found in the CNSS image. The CNSS image also had lower noise level (0.095 mJy/beam compared to 0.119 mJy/beam). Additionally, when our continuum image was compared to the CNSS image, separation showed no dependence on total flux density (in our continuum image). At lower flux densities, sources in our image were brighter than the same ones in the CNSS image. When our continuum image was compared to the FIRST catalog, the spectral index difference showed no dependence on total flux (in our continuum image). In conclusion, the quality of our images did not completely match the quality of the CNSS and FIRST images. More work is needed in developing the new imaging scripts.

  8. Integrated, multidisciplinary reservoir characterization, modeling and engineering leading to enhanced oil recovery from the Midway-Sunset field, California

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, S.; Forster, C.; Deo, M. (Univ. of Utah, Salt Lake City, UT (United States)) (and others)

    1996-01-01

    The Pru Fee property is developed in a heavy oil, Class III (slope and basin clastic sand), reservoir of the Midway-Sunset field, San Joaquin Basin, California. Wells on the property were shut-in with an estimated 85% of the original oil remaining in place because the reservoir failed to respond to conventional cyclic steaming. Producibility problems are attributed to the close proximity of the property to the margin of the field. Specific problems include complex reservoir geometry, thinning pay, bottom water, and dipping beds. These problems are likely common at the margins of the Midway-Sunset and other Class III reservoirs. This project forms the first step in returning the property to production and explores strategies that might be applied elsewhere. Reservoir characterization, modeling, and engineering methods are integrated to design, simulate, and implement a pilot steam flood. A new drillhole provides good quality, core through the pay zone and a full suite of geophysical logs. Correlations between geological and petrophysical data are used to extrapolate reservoir conditions from older logs and yield a 3-dimensional petrophysical model. Numerical results illustrate how each producibility problem might influence production and provide a framework for designing the pilot steam flood. This first phase illustrates how a multidisciplinary team can use established technologies in developing the detailed petrophysical, geological, and numerical models needed to enhance oil recovery from marginal areas of Class III reservoirs.

  9. Integrated, multidisciplinary reservoir characterization, modeling and engineering leading to enhanced oil recovery from the Midway-Sunset field, California

    Energy Technology Data Exchange (ETDEWEB)

    Schamel, S.; Forster, C.; Deo, M. [Univ. of Utah, Salt Lake City, UT (United States)] [and others

    1996-12-31

    The Pru Fee property is developed in a heavy oil, Class III (slope and basin clastic sand), reservoir of the Midway-Sunset field, San Joaquin Basin, California. Wells on the property were shut-in with an estimated 85% of the original oil remaining in place because the reservoir failed to respond to conventional cyclic steaming. Producibility problems are attributed to the close proximity of the property to the margin of the field. Specific problems include complex reservoir geometry, thinning pay, bottom water, and dipping beds. These problems are likely common at the margins of the Midway-Sunset and other Class III reservoirs. This project forms the first step in returning the property to production and explores strategies that might be applied elsewhere. Reservoir characterization, modeling, and engineering methods are integrated to design, simulate, and implement a pilot steam flood. A new drillhole provides good quality, core through the pay zone and a full suite of geophysical logs. Correlations between geological and petrophysical data are used to extrapolate reservoir conditions from older logs and yield a 3-dimensional petrophysical model. Numerical results illustrate how each producibility problem might influence production and provide a framework for designing the pilot steam flood. This first phase illustrates how a multidisciplinary team can use established technologies in developing the detailed petrophysical, geological, and numerical models needed to enhance oil recovery from marginal areas of Class III reservoirs.

  10. The Dancing Sky: 6 years of night sky observations at Cerro Paranal

    CERN Document Server

    Patat, F

    2008-01-01

    The present work provides the results of the first six years of operation of the systematic night-sky monitoring at ESO-Paranal (Chile). The UBVRI night-sky brightness was estimated on about 10,000 VLT-FORS1 archival images, obtained on more than 650 separate nights, distributed over 6 years and covering the descent from maximum to minimum of sunspot cycle n.23. Additionally, a set of about 1,000 low resolution, optical night-sky spectra have been extracted and analyzed. The unprecedented database discussed in this paper has led to the detection of a clear seasonal variation of the broad band night sky brightness in the VRI passbands, similar to the well known semi-annual oscillation of the NaI D doublet. The spectroscopic data demonstrate that this seasonality is common to all spectral features, with the remarkable exception of the OH rotational-vibrational bands. A clear dependency on the solar activity is detected in all passbands and it is particularly pronounced in the U band, where the sky brightness de...

  11. “Native Skywatchers - Earth Sky Mirroring, Kapemni Pairs - Ojibwe and D(L)akota Sacred Star Sites “

    Science.gov (United States)

    Lee, Annette S.; Gawboy, Carl; Rock, Jim; Wilson, William; Tibbetts, Jeff; O'Rourke, Charleen

    2015-08-01

    Late in February, deep in the heart of the northern hemisphere winter, Ojibwe people know to look to the east a few hours after sunset and offer tobacco to Mizhi Bizhiw -Curly Tail, the Great Spirit Cat in the night sky. There are many beautiful and layered teachings about Mizhi Bizhiw - Curly Tail relating to the coming of spring, respect for the water, sugar bush camp, but most important; knowing the stars meant survival.Painted high on the granite rock cliffs above the glacial waters in red ochre is the Mizhi Bizhiw - Curly Tail constellation. Along with the Ojibwe lion are two neighboring seasonal constellations: Mooz (Pegasus) and Biboonkionini -Wintermaker (Orion+). On Lake Hegman in the Boundary Waters Canoe Area located near Ely, Minnesota, a sacred reflection, an earth-sky mirroring is illustrated. It is here that tangible and intangible star knowledge meet.In D(L)akota star knowledge one of the most important teachings is kapemni. Wrapped up in this one word are layers of meaning that can be thought of as ‘As it is above; it is below.’ Imagine two tipis stacked vertically. The top triangle is inverted so that the pair meets at the apex. It is understood that the top realm represents the sky above, the stars or the spirit world. The bottom tipi represents the Earth, the material or the physical world.On Summer Solstice each year the Sun can be found in the Mato Tipila - Bear’s Lodge D(L)akota constellation (Gemini). The day when this astronomical alignment happens is known as the ‘Wacipi - Sundance Ceremony in the Stars’. At this time traditionally D(L)akota people would meet at Mato Tipila Paha - Grey Horn Butte (Devil’s Tower) in northeast Wyoming and participate in the earthly Wacipi - Sun Dance ceremony. This is a beautiful example of a kapemni pair or an earth-sky mirroring.Presented here are just two examples of sacred star sites found in our region: Minnesota, North & South Dakota, US. These are examples of cultural heritage that is

  12. Traces on sky. Unexpected results of regular observations

    Science.gov (United States)

    Churyumov, K. I.; Steklov, A. F.; Vidmachenko, A. P.; Dashkiev, N. G.; Steklov, E. A.

    2016-08-01

    If the fireball's track has noticeable angular size, it can be seen even in the daytime. After the flight, bolide remains a noticeable trace of a dust, dark against the light sky. If such a dust trail illuminated by the rays of the Sun, which had just hid behind the horizon (or even in the moonlight), it is visible as bright lanes in the night sky or in twilight. That's why we call it the twilight bolides. Usually, astronomical observations using of meteor patrols, carried out at night after the evening astronomical twilight. But from March 2013 to October 2015, the authors have obtained several thousands of different tracks in the sky over Kiev. Therefore, we have identified a special class of twilight observations of fireballs. We register the traces of invading to atmosphere of meteoroids of natural and artificial origin. At the same time, observe the traces of fireballs at the day-time are also possible. But they are less effective than in the twilight. Night observations of bright meteoric tracks can usually observe some seconds. While traces of the twilight bolides we observed from some minutes up to two hours, before they be scattered by atmospheric currents. It opens the great prospects for low-cost direct experiments probing of these tracks by using, for example, the astronomical aviation. We propose the twilight tracks are classified into the following types: AMT - aero-meteorological tracks, AST - aero-space, ATT - aero-technical, and NST - not yet classified tracks of unknown nature. During the short period of our observations (from March 2013 to 2016), was fixed falling at least a dozen fragments of cometary nuclei, at least five of sufficiently large and dozens of smaller fragments of meteoroids. The results of our observations also showed that during the morning and evening twilight over Kiev clearly visible the plume of aerosols of technical nature from the plants, factories and other production facilities.

  13. The interactive sky: a browsable allsky image

    Science.gov (United States)

    Tancredi, Gonzalo; Da Rosa, Fernando; Roland, Santiago; Almenares, Luciano; Gomez, Fernando

    2015-08-01

    We are conducting a project to make available panoramas of the night sky of the southern hemisphere, based on a mosaic of hundred of photographs. Each allsky panorama is a giant image composed by hundreds of high-resolution photos taken in the course of one night. The panoramas are accessible with a web-browser and the public is able to zoom on them and to see the sky with better quality than the naked eye. We are preparing 4 sets of panoramas corresponding to the four seasons.The individual images are taken with a 16 Mpixels DLSR camera with a 50 mm lens mounted on a Gigapan EPIC robotic camera mounts. These devices and a autoguiding telescope are mounted in a equatorial telescope mount, which allows us to have exposure of several tens seconds. The images are then processed and stitched to create the gigantic panorama, with typical weight of several GBytes.The limiting magnitude is V~8. The panoramas include more than 50 times more stars those detected with the naked eye.In addition to the allsky panoramas, we embedded higher resolution images of specific regions of interest such as: emission nebulae and dark, open and globular clusters and galaxies; which can be zoomed.The photographs have been acquiring since December 2014 in a dark place with low light pollution in the countryside of Uruguay; which allows us to achieve deep sky objects.These panoramas will be available on a website and can be accessed with any browser.This tool will be available for teaching purposes, astronomy popularization or introductory research. Teacher guides will be developed for educational activities at different educational levels.While there are similar projects like Google Sky, the methodology used to generate the giant panoramas allows a much more realistic view, with a background of continuous sky without sharp edges. Furthermore, while the planetarium software is based on drawings of the stars, our panoramas are based on real images.This is the first project with these

  14. The Biggest Star in the Sky

    Science.gov (United States)

    1997-03-01

    , developed by the Max-Planck Institut for Extraterrestrial Physics (Garching, Germany). Several hundred very short exposures of R Doradus were made, each lasting 0.1 second (this is short enough to freeze the 21 fringe patterns in each exposure). Immediately thereafter, a similar series of observations was made of an unresolved calibrator ' star (Gamma Reticuli). This procedure was repeated several times, producing thousands of images to be analysed. Additional observations were made in 1995 with the NTT as well as the 3.9-m Anglo-Australian Telescope at Siding Spring (Australia). These observations, and the application of different interferometric data analysis techniques to similar data sets, confirmed the results of the earlier ones. The results The results clearly showed that R Doradus is extended, having an angular diameter of 0.057 +- 0.005 arcsec (assuming that the star appears as a uniform disk). This apparent size is 30% larger than Betelgeuse! The bigger a star's apparent diameter, the more easily it can be resolved. The surprise is therefore not only the large diameter of R Doradus, but also the fact that this was not discovered earlier. Many of the larger stars were already measured by Albert Michelson and his team. The reason for the late discovery is most likely the southern latitude of R~Doradus, which makes it inaccessible to the stellar interferometers predominantly located on the northern hemisphere. R Doradus is an inconspicuous star at visible wavelength but is one of the brightest in the sky in the infrared. This led Robert Wing (Ohio State University) to predict in 1971 that R Doradus should have a large angular size. Only now has this prediction been confirmed. The NTT observations were made in the infrared. At first sight it may seem more sensible to observe at shorter, visible wavelengths because this would result in better angular resolution. However, measurements in the infrared - although more difficult to perform - result in a better estimate of

  15. Teach and Touch the Earth and Sky

    Science.gov (United States)

    Florina Tendea, Camelia

    2017-04-01

    My name is Camelia Florina Tendea. I am primary school teacher at "Horea, Closca and Crisan" Secondary School, in Brad, a town in the west side of Transylvania. I am permanently interested to develop my knowledge and teaching skills about space sciences (Earth and Sky) because the new generations of students are very well informed and couriouse about these topics. In this context the teachers must be prepared to deal with such requests in school. Introducing of activity: For a primary school teacher is a real challenge teaching about Earth and Sky, so I consider that a collaboration with science teachers, engineers and other specialists in the sciences is absolutely essential and beneficial in the educational design. In my opinion, the contents about Earth ans Sky-Space in a single word- are very attractive for students and they are a permanent source of discoveries and provide a multidisciplinary vision, so required in the education. Possible contents to teach in primary school: about Earth: -Terra -the third Planet from the Sun; How Earth spins; Land and water; The Earth seen from space, Trip between Earth and Moon,Weather Phenomena; the Poles; about Sky: Solar System, Asteroids, Comets, Meteorites; Rosetta Mission or rendez-vous with a comet; Sun.Moon. Earth. Eclipse;Light Pollution and protection of the night sky; Life in Space. Astronauts and experiences; Mission X:- Train Like an Astronaut;About ISS. For teachers it is important to know from the beginning how they teach, a viable support is the teaching of STEM subjects, which provides access to careers in astronomy, science/technology space. We could teach about earth and sky using different kinds of experiments, simulations, hands-on activities, competitions, exhibitions, video presentations. Competences developed in primary school through these contents: Comunication, individual studying, understanding and valorisation of scientific information, relating to the natural environment. In addition, they are

  16. Ultraluminous infrared galaxies in the AKARI all-sky survey

    Energy Technology Data Exchange (ETDEWEB)

    Kilerci Eser, E., E-mail: ecekilerci@dark-cosmology.dk [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Goto, T. [National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Doi, Y., E-mail: tomo@phys.nthu.edu.tw, E-mail: doi@ea.c.u-tokyo.ac.jp [The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902 (Japan)

    2014-12-10

    We present a new catalog of 118 ultraluminous infrared galaxies (ULIRGs) and one hyperluminous infrared galaxy (HLIRG) by cross-matching the AKARI all-sky survey with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the final data release of the Two-Degree Field Galaxy Redshift Survey. Forty of the ULIRGs and one HLIRG are new identifications. We find that ULIRGs are interacting pair galaxies or ongoing or postmergers. This is consistent with the widely accepted view: ULIRGs are major mergers of disk galaxies. We confirm the previously known positive trend between the active galactic nucleus fraction and infrared luminosity. We show that ULIRGs have a large offset from the main sequence up to z ∼ 1; their offset from the z ∼ 2 'main sequence' is relatively smaller. We find a result consistent with the previous studies showing that, compared to local star-forming SDSS galaxies of similar mass, local ULIRGs have lower oxygen abundances. We demonstrate for the first time that ULIRGs follow the fundamental metallicity relation (FMR). The scatter of ULIRGs around the FMR (0.09 dex-0.5 dex) is comparable to the scatter of z ∼ 2-3 galaxies. We provide the largest local (0.050

  17. Ultraluminous Infrared Galaxies in the AKARI All Sky Survey

    CERN Document Server

    Eser, E Kilerci; Doi, Y

    2014-01-01

    We present a new catalog of 118 Ultraluminous Infrared Galaxies (ULIRGs) and one Hyperluminous Infrared Galaxy (HLIRG) by crossmatching AKARI all-sky survey with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the Final Data Release of the Two-Degree Field Galaxy Redshift Survey (2dFGRS). 40 of the ULIRGs and one HLIRG are new identifications. We find that ULIRGs are interacting pair galaxies or ongoing/post mergers. This is consistent with the widely accepted view: ULIRGs are major mergers of disk galaxies. We confirm the previously known positive trend between the AGN fraction and IR luminosity. We show that ULIRGs have a large off-set from the 'main sequence' up to z~1; their off-set from the z~2 'main sequence' is relatively smaller. We find a consistent result with the previous studies showing that compared to local star forming SDSS galaxies of similar mass, local ULIRGs have lower oxygen abundances. We for the first time demonstrate that ULIRGs follow the fundamental metallicity relation (...

  18. The Python Sky Model: software for simulating the Galactic microwave sky

    CERN Document Server

    Thorne, Ben; Alonso, David; Naess, Sigurd

    2016-01-01

    We present a numerical code to simulate maps of Galactic emission in intensity and polarization at microwave frequencies, aiding in the design of Cosmic Microwave Background experiments. This Python code builds on existing efforts to simulate the sky by providing an easy-to-use interface and is based on publicly available data from the WMAP and Planck satellite missions. We simulate synchrotron, thermal dust, free-free, and anomalous microwave emission over the whole sky, in addition to the Cosmic Microwave Background, and include a set of alternative prescriptions for the frequency dependence of each component that are consistent with current data. We also present a prescription for adding small-scale realizations of these components at resolutions greater than current all-sky measurements. The code is available at https://github.com/bthorne93/PySM_public.

  19. North error estimation based on solar elevation errors in the third step of sky-polarimetric Viking navigation.

    Science.gov (United States)

    Száz, Dénes; Farkas, Alexandra; Barta, András; Kretzer, Balázs; Egri, Ádám; Horváth, Gábor

    2016-07-01

    The theory of sky-polarimetric Viking navigation has been widely accepted for decades without any information about the accuracy of this method. Previously, we have measured the accuracy of the first and second steps of this navigation method in psychophysical laboratory and planetarium experiments. Now, we have tested the accuracy of the third step in a planetarium experiment, assuming that the first and second steps are errorless. Using the fists of their outstretched arms, 10 test persons had to estimate the elevation angles (measured in numbers of fists and fingers) of black dots (representing the position of the occluded Sun) projected onto the planetarium dome. The test persons performed 2400 elevation estimations, 48% of which were more accurate than ±1°. We selected three test persons with the (i) largest and (ii) smallest elevation errors and (iii) highest standard deviation of the elevation error. From the errors of these three persons, we calculated their error function, from which the North errors (the angles with which they deviated from the geographical North) were determined for summer solstice and spring equinox, two specific dates of the Viking sailing period. The range of possible North errors ΔωN was the lowest and highest at low and high solar elevations, respectively. At high elevations, the maximal ΔωN was 35.6° and 73.7° at summer solstice and 23.8° and 43.9° at spring equinox for the best and worst test person (navigator), respectively. Thus, the best navigator was twice as good as the worst one. At solstice and equinox, high elevations occur the most frequently during the day, thus high North errors could occur more frequently than expected before. According to our findings, the ideal periods for sky-polarimetric Viking navigation are immediately after sunrise and before sunset, because the North errors are the lowest at low solar elevations.

  20. North error estimation based on solar elevation errors in the third step of sky-polarimetric Viking navigation

    Science.gov (United States)

    Száz, Dénes; Farkas, Alexandra; Barta, András; Kretzer, Balázs; Egri, Ádám; Horváth, Gábor

    2016-07-01

    The theory of sky-polarimetric Viking navigation has been widely accepted for decades without any information about the accuracy of this method. Previously, we have measured the accuracy of the first and second steps of this navigation method in psychophysical laboratory and planetarium experiments. Now, we have tested the accuracy of the third step in a planetarium experiment, assuming that the first and second steps are errorless. Using the fists of their outstretched arms, 10 test persons had to estimate the elevation angles (measured in numbers of fists and fingers) of black dots (representing the position of the occluded Sun) projected onto the planetarium dome. The test persons performed 2400 elevation estimations, 48% of which were more accurate than ±1°. We selected three test persons with the (i) largest and (ii) smallest elevation errors and (iii) highest standard deviation of the elevation error. From the errors of these three persons, we calculated their error function, from which the North errors (the angles with which they deviated from the geographical North) were determined for summer solstice and spring equinox, two specific dates of the Viking sailing period. The range of possible North errors ΔωN was the lowest and highest at low and high solar elevations, respectively. At high elevations, the maximal ΔωN was 35.6° and 73.7° at summer solstice and 23.8° and 43.9° at spring equinox for the best and worst test person (navigator), respectively. Thus, the best navigator was twice as good as the worst one. At solstice and equinox, high elevations occur the most frequently during the day, thus high North errors could occur more frequently than expected before. According to our findings, the ideal periods for sky-polarimetric Viking navigation are immediately after sunrise and before sunset, because the North errors are the lowest at low solar elevations.

  1. Cloud Screening and Quality Control Algorithm for Star Photometer Data: Assessment with Lidar Measurements and with All-sky Images

    Science.gov (United States)

    Ramirez, Daniel Perez; Lyamani, H.; Olmo, F. J.; Whiteman, D. N.; Navas-Guzman, F.; Alados-Arboledas, L.

    2012-01-01

    This paper presents the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. These algorithms are necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, delta Ae(lambda), and precipitable water vapor content, W, at nighttime. This cloud screening procedure consists of calculating moving averages of delta Ae() and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable Ae(lambda) and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16 N, 3.60 W, 680 ma.s.l.; South-East of Spain) for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  2. Cloud screening and quality control algorithm for star photometer data: assessment with lidar measurements and with all-sky-images

    Directory of Open Access Journals (Sweden)

    D. Pérez-Ramírez

    2012-02-01

    Full Text Available This paper present the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. This kind of algorithms is necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, δAe(λ, and precipitable water vapor content, W, at night-time. This cloud screening procedure consists of calculating moving averages of δAe(λ and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable δAe(λ and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16° N, 3.60° W, 680 m a.s.l.; South-East of Spain for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  3. Cloud screening and quality control algorithm for star photometer data: assessment with lidar measurements and with all-sky images

    Directory of Open Access Journals (Sweden)

    D. Pérez-Ramírez

    2012-07-01

    Full Text Available This paper presents the development and set up of a cloud screening and data quality control algorithm for a star photometer based on CCD camera as detector. These algorithms are necessary for passive remote sensing techniques to retrieve the columnar aerosol optical depth, δAe(λ, and precipitable water vapor content, W, at nighttime. This cloud screening procedure consists of calculating moving averages of δAe(λ and W under different time-windows combined with a procedure for detecting outliers. Additionally, to avoid undesirable δAe(λ and W fluctuations caused by the atmospheric turbulence, the data are averaged on 30 min. The algorithm is applied to the star photometer deployed in the city of Granada (37.16° N, 3.60° W, 680 m a.s.l.; South-East of Spain for the measurements acquired between March 2007 and September 2009. The algorithm is evaluated with correlative measurements registered by a lidar system and also with all-sky images obtained at the sunset and sunrise of the previous and following days. Promising results are obtained detecting cloud-affected data. Additionally, the cloud screening algorithm has been evaluated under different aerosol conditions including Saharan dust intrusion, biomass burning and pollution events.

  4. Causality and skies: is non-refocussing necessary?

    Science.gov (United States)

    Bautista, A.; Ibort, A.; Lafuente, J.

    2015-05-01

    The causal structure of a strongly causal, null pseudo-convex, space-time M is completely characterized in terms of a partial order on its space of skies defined by means of a class of non-negative Legendrian isotopies called sky isotopies. It is also shown that such partial order is determined by the class of future causal celestial curves, that is, curves in the space of light rays which are tangent to skies and such that they determine non-negative sky isotopies. It will also be proved that the space of skies Σ equipped with Low’s (or reconstructive) topology is homeomorphic and diffeomorphic to M under the only additional assumption that M separates skies, that is, that different events determine different skies. The sky-separating property of M is sharp and the previous result provides an answer to the question about the class of space-times whose causal structure, topological and differentiable structure can be reconstructed from their spaces of light rays and skies. These results can be understood as a Malament-Hawking-like theorem stated in terms of the partial order defined on the space of skies.

  5. Integration of polarization and chromatic cues in the insect sky compass.

    Science.gov (United States)

    el Jundi, Basil; Pfeiffer, Keram; Heinze, Stanley; Homberg, Uwe

    2014-06-01

    Animals relying on a celestial compass for spatial orientation may use the position of the sun, the chromatic or intensity gradient of the sky, the polarization pattern of the sky, or a combination of these cues as compass signals. Behavioral experiments in bees and ants, indeed, showed that direct sunlight and sky polarization play a role in sky compass orientation, but the relative importance of these cues are species-specific. Intracellular recordings from polarization-sensitive interneurons in the desert locust and monarch butterfly suggest that inputs from different eye regions, including polarized-light input through the dorsal rim area of the eye and chromatic/intensity gradient input from the main eye, are combined at the level of the medulla to create a robust compass signal. Conflicting input from the polarization and chromatic/intensity channel, resulting from eccentric receptive fields, is eliminated at the level of the anterior optic tubercle and central complex through internal compensation for changing solar elevations, which requires input from a circadian clock. Across several species, the central complex likely serves as an internal sky compass, combining E-vector information with other celestial cues. Descending neurons, likewise, respond both to zenithal polarization and to unpolarized cues in an azimuth-dependent way.

  6. Uniform Access to Astronomical Web Services and its Implementation in SkyMouse

    Science.gov (United States)

    Sun, Hua-Ping; Cui, Chen-Zhou; Zhao, Yong-Heng

    2008-06-01

    With the progress of information technologies and astronomical observation technologies, as an example of cyber-infrastructure based sciences, the Virtual Observatory (VO) is initiated and spreaded quickly. More and more on-line accessible database systems and different kinds of services are available. Although astronomers have been aware of the importance of the interoperability, integrated access to the on-line information is still difficult. The SkyMouse is a smart system developed by Chinese Virtual Observatory project to let us access different online resource systems easier than ever. Not like some VO efforts on uniformed access systems, for example, NVO DataScope, SkyMouse tries to show a comprehensive overview for a specific object, but not to snatch as much data as possible. Stimulated by a simple "Mouse Over" on an interested object name, various VO-compliant and traditional databases, i.e. SIMBAD, NED, VizieR, DSS, ADS, are queried by the SkyMouse. An overview for the given object, including basic information, image, observation and references, is displayed in the user's default web browser. In this article, the authors will introduce the framework of SkyMouse. During the development of SkyMouse, various Web services will be called. In order to invoke these Web services, two problems must be solved, i.e. interoperability and performance. In the paper, a detailed description for these problems and the authors' resolution are given.

  7. On the Non-Gaussianity Observed in the COBE-DMR Sky Maps

    CERN Document Server

    Banday, A J; Górski, K M

    1999-01-01

    In this paper we pursue the origin of the non-Gaussianity determined by a bispectrum analysis of the COBE-DMR 4-year sky maps. The robustness of the statistic is demonstrated by the rebinning of the data into 12 coordinate systems. By computing the bispectrum statistic as a function of various data partitions - by channel, frequency, and time interval, we show that the observed non-Gaussian signal is driven by the 53 GHz data. This frequency dependence strongly rejects the hypothesis that the signal is cosmological in origin. A jack-knife analysis of the coadded 53 and 90 GHz sky maps reveals those sky pixels to which the bispectrum statistic is particularly sensitive. We find that by removing data from the 53 GHz sky maps for periods of time during which a known systematic effect perturbs the 31 GHz channels, the amplitudes of the bispectrum coefficients become completely consistent with that expected for a Gaussian sky. We conclude that the non-Gaussian signal detected by the normalised bispectrum statistic...

  8. The spectral amplification effect of clouds to the night sky radiance in Madrid

    Science.gov (United States)

    Aubé, M.; Kocifaj, M.; Zamorano, J.; Solano Lamphar, H. A.; Sanchez de Miguel, A.

    2016-09-01

    Artificial Light at Night (ALAN) may have various environmental impacts ranging from compromising the visibility of astronomical objects to the perturbation of circadian cycles in animals and humans. In the past much research has been carried out to study the impact of ALAN on the radiance of the night sky during clear sky conditions. This was mainly justified by the need for a better understanding of the behavior of ALAN propagation into the environment in order to protect world-class astronomical facilities. More recently, alongside to the threat to the natural starry sky, many issues have emerged from the biological science community. It has been shown that, nearby or inside cities, the presence of cloud cover generally acts as an amplifier for artificial sky radiance while clouds behave as attenuators for remote observers. In this paper we show the spectral behavior of the zenith sky radiance amplification factor exerted by clouds inside a city. We compare in-situ measurements made with the spectrometer SAND-4 with a numerical model applied to the specific geographical context of the Universidad Complutense de Madrid in Spain.

  9. 液相-子空间夹角判据联用分析饮料中的柠檬黄和日落黄%Analysis of Tartrazine and Sunset Yellow in Drinks Based on HPLC and Vector-Subspace Angle Criterion

    Institute of Scientific and Technical Information of China (English)

    宋光均; 刘柳; 粟晖; 孙增强; 罗嘉利

    2015-01-01

    通过液相-光谱联用,采用向量-子空间夹角判据进行计算,建立了饮料中柠檬黄和日落黄的分析方法。该方法先采用全波长光纤光谱仪建立不同浓度柠檬黄和日落黄的标准光谱数据库,以及市售碳酸型饮料和功能型饮料的样品光谱数据,再进行液相-光谱联用,得到扣除饮料中待测组分后的本底光谱数据;运用向量-子空间夹角判据进行计算饮料中柠檬黄和日落黄的含量。试验结果表明,在3~30μg/mL内柠檬黄和日落黄的标准工作曲线线性关系良好(R2柠檬黄=0.9976,R2日落黄=0.9998);向量-子空间夹角判据计算结果与高效液相色谱法测定结果比较,相对误差小于2.5%,样本加标回收率为89.5%~109.0%, RSD为4.9%~6.1%,该方法能满足定量分析需求。%In this paper,a new analysis method for testing tartrazine and the sunset yellow in drinks was established based on vector-subspace criterion with high performance liquid chromatography and spectrometer. At first, the spectral databases of the drinks and the standard spectral databases of tartrazine, sunset yellow were constructed by multi-wavelength spectrometer. Then the multi-wavelength UV spectral databases of drinks background were constructed after the tartrazine or the sunset yellow was decucted from drinks by HPLC-spectrometer, respectively. Three kinds of spectral libraries were computed to analysis for determinating the tartrazine and the sunset yellow in drinks based on Vector-subspace angle criterion. The results showed that the linear relationship of standard curve of tartrazine and sunset yellow were good in the range of 3~30μg/mL (R2tartrazine=0.999 8,R2sunset yelow=0.999 8). Comparing the results of vector-space angle criterion with the results of high performance liquid chromatography, the RSDs were less than 2.50%. And the recoveries of tartrazine, sunset yellow were 89.5%~109.0%with RSDs of 4.9%~6.1%, so the method met the requirement

  10. Comparing pymorph and SDSS photometry - I. Background sky and model fitting effects

    Science.gov (United States)

    Fischer, J.-L.; Bernardi, M.; Meert, A.

    2017-05-01

    A number of recent estimates of the total luminosities of galaxies in the SDSS are significantly larger than those reported by the Sloan Digital Sky Survey (SDSS) pipeline. This is because of a combination of three effects: one is simply a matter of defining the scale out to which one integrates the fit when defining the total luminosity, and amounts on average to ≤0.1 mag even for the most luminous galaxies. The other two are less trivial and tend to be larger; they are due to differences in how the background sky is estimated and what model is fit to the surface brightness profile. We show that pymorph sky estimates are fainter than those of the Sloan Digital Sky Servey Data Release 7 or Data Release 9 pipelines, but are in excellent agreement with the estimates of Blanton et al. Using the SDSS sky biases luminosities by more than a few tenths of a magnitude for objects with half-light radii ≥7 arcsec. In the SDSS main galaxy sample, these are typically luminous galaxies, so they are not necessarily nearby. This bias becomes worse when allowing the model more freedom to fit the surface brightness profile. When pymorph sky values are used, then two-component Sérsic-exponential fits to E+S0s return more light than single component deVaucouleurs fits (up to ˜0.2 mag), but less light than single Sérsic fits (0.1 mag). Finally, we show that pymorph fits of Meert et al. to DR7 data remain valid for DR9 images. Our findings show that, especially at large luminosities, these pymorph estimates should be preferred to the SDSS pipeline values.

  11. Results from BASS, the BANYAN All-Sky Survey

    CERN Document Server

    Gagné, Jonathan; Doyon, René; Faherty, Jacqueline K; Malo, Lison; Artigau, Étienne

    2014-01-01

    We present results from the BANYAN All-Sky Survey (BASS), a systematic all-sky survey for brown dwarf candidates in young moving groups. We describe a cross-match of the 2MASS and AllWISE catalogs that provides a list of 98 970 potential nearby dwarfs with spectral types later than M5 with measurements of proper motion at precisions typically better than 15 mas yr$^{-1}$, as well as the Bayesian Analysis for Nearby Young AssociatioNs II tool (BANYAN II) which we use to build the BASS catalog from this 2MASS-AllWISE cross-match, consisting of more than 300 candidate members of young moving groups. We present the first results of a spectroscopic follow-up of those candidates, which allowed us to identify several new low-mass stars and brown dwarfs displaying signs of low gravity. We use the BASS catalog to show tentative evidence for mass segregation in AB Doradus and Argus, and reveal a new $\\sim$ 13 M$_{Jup}$ co-moving companion to a young low-mass star in BASS. We obtain a moderate-resolution near-infrared s...

  12. Results from BASS, the BANYAN All-Sky Survey

    Science.gov (United States)

    Gagne, Jonathan; Lafreniere, David; Doyon, Rene; Faherty, Jacqueline K.; Malo, Lison; Artigau, Etienne

    2015-01-01

    We present results from the BANYAN All-Sky Survey (BASS), a systematic all-sky survey for brown dwarf candidates in young moving groups. We describe a cross-match of the 2MASS and ALLWISE catalogs that provides a list of 98 970 potential nearby dwarfs with spectral types later than M5 with measurements of proper motion at precisions typically better than 15 masyr, as well as the Bayesian Analysis for Nearby Young AssociatioNs II tool (BANYAN II) which we use to build the BASS catalog from this 2MASS-ALLWISE cross-match, consisting of more than 300 candidate members of young moving groups. We present the first results of a spectroscopic follow-up of those candidates, which allowed us to identify several new low-mass stars and brown dwarfs displaying signs of low gravity. We use the BASS catalog to show tentative evidence for mass segregation in AB Doradus and Argus, and reveal a new ˜ 13 Mjup\\ co-moving companion to a young low-mass star in BASS. We obtain a moderate-resolution near-infrared spectrum for the companion, which reveals typical signs of youth and a spectral type L4γ.

  13. The cosmological principle is not in the sky

    Science.gov (United States)

    Park, Chan-Gyung; Hyun, Hwasu; Noh, Hyerim; Hwang, Jai-chan

    2017-08-01

    The homogeneity of matter distribution at large scales, known as the cosmological principle, is a central assumption in the standard cosmological model. The case is testable though, thus no longer needs to be a principle. Here we perform a test for spatial homogeneity using the Sloan Digital Sky Survey Luminous Red Galaxies (LRG) sample by counting galaxies within a specified volume with the radius scale varying up to 300 h-1 Mpc. We directly confront the large-scale structure data with the definition of spatial homogeneity by comparing the averages and dispersions of galaxy number counts with allowed ranges of the random distribution with homogeneity. The LRG sample shows significantly larger dispersions of number counts than the random catalogues up to 300 h-1 Mpc scale, and even the average is located far outside the range allowed in the random distribution; the deviations are statistically impossible to be realized in the random distribution. This implies that the cosmological principle does not hold even at such large scales. The same analysis of mock galaxies derived from the N-body simulation, however, suggests that the LRG sample is consistent with the current paradigm of cosmology, thus the simulation is also not homogeneous in that scale. We conclude that the cosmological principle is neither in the observed sky nor demanded to be there by the standard cosmological world model. This reveals the nature of the cosmological principle adopted in the modern cosmology paradigm, and opens a new field of research in theoretical cosmology.

  14. The ROSAT All-Sky Survey Bright Source Catalogue

    CERN Document Server

    Voges, W; Boller, T; Bräuninger, H; Briel, U G; Burkert, W K A; Dennerl, K; Englhauser, J; Gruber, R; Haberl, F; Hartner, G; Hasinger, G; Pfeffermann, E; Pietsch, W; Predehl, P; Rosso, C; Schmitt, J H M M; Trümper, J E; Zimmermann, H U; Voges, Wolfgang; Aschenbach, Bernd; Boller, Thomas; Braeuninger, Heinrich; Briel, Ulrich; Burkert, Wolfgang; Dennerl, Konrad; Englhauser, Jakob; Gruber, Rainer; Haberl, Frank; Hartner, Gisela; Hasinger, Guenther; Pfeffermann, Elmar; Pietsch, Wolfgang; Predehl, Peter; Rosso, Cristina; Schmitt, Juergen H.M.M.; Truemper, Joachim; Zimmermann, Hans-Ulrich

    1999-01-01

    We present the ROSAT All-Sky Survey Bright Source Catalogue (RASS-BSC, revision 1RXS) derived from the all-sky survey performed during the first half year (1990/91) of the ROSAT mission. 18,811 sources are catalogued (i) down to a limiting ROSAT PSPC count-rate of 0.05 cts/s in the 0.1-2.4 keV energy band, (ii) with a detection likelihood of at least 15 and (iii) at least 15 source counts. The 18,811 sources underwent both an automatic validation and an interactive visual verification process in which for 94% of the sources the results of the standard processing were confirmed. The remaining 6% have been analyzed using interactive methods and these sources have been flagged. Flags are given for (i) nearby sources; (ii) sources with positional errors; (iii) extended sources; (iv) sources showing complex emission structures; and (v) sources which are missed by the standard analysis software. Broad band (0.1-2.4 keV) images are available for sources flagged by (ii), (iii) and (iv). For each source the ROSAT name...

  15. The SPHEREx All-Sky Spectroscopic Survey

    Science.gov (United States)

    Unwin, Stephen C.; SPHEREx Science Team, SPHEREx Project Team

    2016-06-01

    SPHEREx is a mission to conduct an optical-near-IR survey of the entire sky with a spectrum at every pixel location. It was selected by NASA for a Phase A study in its Small Explorer Program; if selected, development would begin in 2016, and the observatory would start a 2-year prime mission in 2020. An all-sky spectroscopic survey can be used to tackle a wide range of science questions. The SPHEREx science team is focusing on three: (1) Probing the physics of inflation through measuring non-Gaussianity from the study of large-scale structure; (2) Studying the origin of water and biogenic molecules in a wide range of physical and chemical environments via ice absorption spectra; (3) Charting the history of star formation in the universe through intensity mapping of the large-scale spatial power. The instrument is a small wide-field telescope operating in the range of 0.75 - 4.8 µm at a spectral resolution of 41.5 in the optical and 150 at the long-wavelength end. It observes in a sun-sync low-earth orbit, covering the sky like WISE and COBE. SPHEREx is a simple instrument that requires no new technology. The Phase A design has substantial technical and resource margins and can be built with low risk. It is a partnership between Caltech and JPL, with Ball Aerospace and the Korea Astronomy and Space Science Institute as major partners. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  16. Sloan Digital Sky Survey Photometric Calibration Revisited

    Science.gov (United States)

    Marriner, J.

    2016-05-01

    The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

  17. Lost Skies of Italian Folk Astronomy

    Science.gov (United States)

    Barale, Piero

    The limited archival material and the scarcity of evidence from the oldest living representatives of various communities effectively restrict research on archaic astronomical knowledge within Italy to the Alpine area and the most northerly part of the Appenines. These are territories where, fortunately, the folk culture is historically recognized as being very conservative. The sky provided a series of "astral instruments" used for planning religious festivals, fairs, and work in the fields through an empirical-symbolic approach and ancient sidereal calendars with which the valley dwellers were able to arrange daily life.

  18. Polygons and practice in Skies of Arcadia

    Directory of Open Access Journals (Sweden)

    Zoya Street

    2013-03-01

    Full Text Available This paper features research carried out at the Victoria and Albert Museum into the design history of Sega’s 2000 Dreamcast title, Skies of Arcadia (released in Japan as Eternal Arcadia. It was released by Overworks, a subsidiary of Sega, at an interesting point in Japanese computer game history. A new generation of video game consoles was in its infancy, and much speculation in the industry surrounded how networked gaming and large, open, tridimensional game worlds would change game design in the years ahead.

  19. Sloan Digital Sky Survey Photometric Calibration Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Marriner, John; /Fermilab

    2012-06-29

    The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

  20. ACTPol: On-Sky Performance and Characterization

    Science.gov (United States)

    Grace, E.; Beall, J.; Bond, J. R.; Cho, H. M.; Datta, R.; Devlin, M. J.; Dunner, R.; Fox, A. E.; Gallardo, P.; Hasselfield, M.; Henderson, S.; Hilton, G. C.; Hincks, A. D.; Hlozek, R.; Hubmayr, J.; Irwin, K.; Klein, J.; Koopman, B.; Li, D.; Lungu, M.; Newburgh, L.; Nibarger, J. P.; Niemack, M. D.; Maurin, L.; Wollack, E. J.

    2014-01-01

    ACTPol is the polarization-sensitive receiver on the Atacama Cosmology Telescope. ACTPol enables sensitive millimeter wavelength measurements of the temperature and polarization anisotropies of the Cosmic Microwave Background (CMB) at arcminute angular scales. These measurements are designed to explore the process of cosmic structure formation, constrain or determine the sum of the neutrino masses, probe dark energy, and provide a foundation for a host of other cosmological tests. We present an overview of the first season of ACTPol observations focusing on the optimization and calibration of the first detector array as well as detailing the on-sky performance.

  1. The stargazer's guide to the night sky

    CERN Document Server

    Lisle, Jason, Dr

    2012-01-01

    Explore the night sky, identify stars, constellations, and even planets. Stargaze with a telescope, binoculars, or even your naked eye. Allow Dr. Jason Lisle, a research scientist with a masters and PhD in astrophysics, to guide you in examining the beauty of God's Creation with 150 full color star-charts. Learn the best ways and optimal times to observe planets and stars with easy to use illustrations. Create or expand the hobby of stargazing; an outdoor, educational hobby to enjoy with friends or family.

  2. SPHEREx: An All-Sky Spectral Survey

    Science.gov (United States)

    Bock, James; SPHEREx Science Team

    2016-01-01

    SPHEREx, a mission in NASA's Small Explorer (SMEX) program that was selected for Phase A in July 2015, is an all-sky survey satellite designed to address all three science goals in NASA's astrophysics division, in a single survey, with a single instrument. We will probe the physics of inflation by measuring non-Gaussianity by studying large-scale structure, surveying a large cosmological volume at low redshifts, complementing high-z surveys optimized to constrain dark energy. The origin of water and biogenic molecules will be investigated in all phases of planetary system formation - from molecular clouds to young stellar systems with protoplanetary disks - by measuring ice absorption spectra. We will chart the origin and history of galaxy formation through a deep survey mapping large-scale spatial power. Finally, SPHEREx will be the first all-sky near-infrared spectral survey, creating a legacy archive of spectra (0.75 - 4.8 um at R = 41.5 and 150) with high sensitivity using a cooled telescope with large mapping speed.SPHEREx will observe from a sun-synchronous low-earth orbit, covering the entire sky in a manner similar to IRAS, COBE and WISE. During its two-year mission, SPHEREx will produce four complete all-sky maps for constraining the physics of inflation. These same maps contain numerous high signal-to-noise absorption spectra to study water and biogenic ices. The orbit naturally covers two deep regions at the celestial poles, which we use for studying galaxy evolution. All aspects of the SPHEREx instrument and spacecraft have high heritage. SPHEREx requires no new technologies and carries large technical and resource margins on every aspect of the design. The projected instrument sensitivity, based on conservative performance estimates, meets the driving point source sensitivity requirement with 300 % margin.SPHEREx is a partnership between Caltech and JPL, following the successful management structure of the NuSTAR and GALEX SMEX missions. The spacecraft

  3. Uncertainties of parameterized near-surface downward longwave and clear-sky direct radiation

    Directory of Open Access Journals (Sweden)

    S. Gubler

    2012-01-01

    Full Text Available As many environmental models rely on simulating the energy balance at the Earth's surface based on parameterized radiative fluxes, knowledge of the inherent uncertainties is important. In this study we evaluate one parameterization of clear-sky incoming shortwave radiation (SDR and diverse parameterizations of clear-sky and all-sky incoming longwave radiation (LDR. In a first step, the clear-sky global SDR is estimated based measured input variables and mean parameter values for hourly time steps during the year 1996 to 2008, and validated using the high quality measurements of seven Alpine Surface Radiation Budget (ASRB stations in Switzerland covering different elevations. Then, twelve clear-sky LDR parameterizations are fitted to the ASRB measurements. One of the best performing LDR parameterizations is chosen to estimate the all-sky LDR based on cloud transmissivity. Cloud transmissivity is estimated using measured and modeled global SDR during daytime. For the night, the performance of several interpolation methods is evaluated.

    Input variable and parameter uncertainties are assigned to estimate the total output uncertainty of the mentioned models, resulting in a mean relative uncertainty of 10% for the clear-sky direct, 15% for diffuse and 2.5% for global SDR, and 2.5% for the fitted all-sky LDR. Further, a function representing the uncertainty in dependence of the radiation is assigned for each model. Validation of the model outputs shows that direct SDR is underestimated (the mean error (ME is around −33 W m−2, while diffuse radiation is overestimated (ME around 19 W m−2. The root mean squared error (RMSE scatters around 60 W m−2 for direct, and 40 W m−2 for diffuse SDR. The best behaviour is found, due to the compensating effects of direct and diffuse SDR, for global SDR with MEs around −13 W m−2 and RMSEs around 40 W m−2. The ME of the fitted all-sky

  4. ARSENIC REMOVAL FROM DRINKING WATER BY POINT OF USE REVERSE OSMOSIS. EPA DEMONSTRATION PROJECT AT SUNSET RANCH DEVELOPMENT IN HOMEDALE, ID. SIX-MONTH EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the first six months of the point of use arsenic removal treatment technology demonstration project at the Sunset Ranch Development in Homedale, ID. The objectives of the project are to evaluate t...

  5. ARSENIC REMOVAL FROM DRINKING WATER BY POINT OF USE REVERSE OSMOSIS. EPA DEMONSTRATION PROJECT AT SUNSET RANCH DEVELOPMENT IN HOMEDALE, ID. SIX-MONTH EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the first six months of the point of use arsenic removal treatment technology demonstration project at the Sunset Ranch Development in Homedale, ID. The objectives of the project are to evaluate t...

  6. Transmedulla Neurons in the Sky Compass Network of the Honeybee (Apis mellifera) Are a Possible Site of Circadian Input.

    Science.gov (United States)

    Zeller, Maximilian; Held, Martina; Bender, Julia; Berz, Annuska; Heinloth, Tanja; Hellfritz, Timm; Pfeiffer, Keram

    2015-01-01

    Honeybees are known for their ability to use the sun's azimuth and the sky's polarization pattern for spatial orientation. Sky compass orientation in bees has been extensively studied at the behavioral level but our knowledge about the underlying neuronal systems and mechanisms is very limited. Electrophysiological studies in other insect species suggest that neurons of the sky compass system integrate information about the polarization pattern of the sky, its chromatic gradient, and the azimuth of the sun. In order to obtain a stable directional signal throughout the day, circadian changes between the sky polarization pattern and the solar azimuth must be compensated. Likewise, the system must be modulated in a context specific way to compensate for changes in intensity, polarization and chromatic properties of light caused by clouds, vegetation and landscape. The goal of this study was to identify neurons of the sky compass pathway in the honeybee brain and to find potential sites of circadian and neuromodulatory input into this pathway. To this end we first traced the sky compass pathway from the polarization-sensitive dorsal rim area of the compound eye via the medulla and the anterior optic tubercle to the lateral complex using dye injections. Neurons forming this pathway strongly resembled neurons of the sky compass pathway in other insect species. Next we combined tracer injections with immunocytochemistry against the circadian neuropeptide pigment dispersing factor and the neuromodulators serotonin, and γ-aminobutyric acid. We identified neurons, connecting the dorsal rim area of the medulla to the anterior optic tubercle, as a possible site of neuromodulation and interaction with the circadian system. These neurons have conspicuous spines in close proximity to pigment dispersing factor-, serotonin-, and GABA-immunoreactive neurons. Our data therefore show for the first time a potential interaction site between the sky compass pathway and the circadian

  7. The AST3 controlling and operating software suite for automatic sky survey

    Science.gov (United States)

    Hu, Yi; Shang, Zhaohui; Ma, Bin; Hu, Keliang

    2016-07-01

    We have developed a specialized software package, called ast3suite, to achieve the remote control and automatic sky survey for AST3 (Antarctic Survey Telescope) from scratch. It includes several daemon servers and many basic commands. Each program does only one single task, and they work together to make AST3 a robotic telescope. A survey script calls basic commands to carry out automatic sky survey. Ast3suite was carefully tested in Mohe, China in 2013 and has been used at Dome, Antarctica in 2015 and 2016 with the real hardware for practical sky survey. Both test results and practical using showed that ast3suite had worked very well without any manual auxiliary as we expected.

  8. On the independent points in the sky for the search of periodic gravitational wave

    CERN Document Server

    Sahay, S K

    2008-01-01

    We investigate the independent points in the sky require to search the periodic gravitational wave, assuming the noise power spectral density to be flat. We have made an analysis with different initial azimuth of the Earth for a week data set. The analysis shows significant difference in the independent points in the sky for the search. We numerically obtain an approximate relation to make trade-off between computational cost and sensitivities. We also discuss the feasibility of the coherent search in small frequency band in reference to advanced LIGO.

  9. Pi of the Sky involvement in LSC-Virgo electromagnetic follow-up project

    Science.gov (United States)

    ZadroŻny, Adam; Sokołowski, Marcin; Mankiewicz, Lech; Żarnecki, Aleksander Filip

    2016-09-01

    Pi of the Sky took part in LSC-Virgo's Electromagnetic (EM) Follow-up project during first science run of Advanced LIGO detectors between September 2015 and January 2016. More than 60 astronomical teams have signed Memorandum-of-Understanding with LSC-Virgo for EM Follow-up project. LSC-Virgo's EM Follow-up is aimed for searching electromagnetic counterparts to gravitational wave transient candidates. Observing an event both in EM and gravitational wave band might be a important step forward to multi-messenger astronomy. The aim of this paper is to show algorithms used by Pi of the Sky for analysing data taken during the science runs.

  10. An all-sky catalog of solar-type dwarfs for exoplanetary transit surveys

    CERN Document Server

    Nascimbeni, V; Ortolani, S; Giuffrida, G; Marrese, P M; Magrin, D; Ragazzoni, R; Pagano, I; Rauer, H; Cabrera, J; Pollacco, D; Heras, A M; Deleuil, M; Gizon, L; Granata, V

    2016-01-01

    Most future surveys designed to discover transiting exoplanets, including TESS and PLATO, will target bright (V3.0 subgiants. The relatively low amount of contamination (defined as the fraction of false positives; <30%) also makes UCAC4-RPM a useful tool for the past and ongoing ground-based transit surveys, which need to discard candidate signals originating from early-type or giant stars. As an application, we show how UCAC4-RPM may support the preparation of the TESS (that will map almost the entire sky) input catalog and the input catalog of PLATO, planned to survey more than half of the whole sky with exquisite photometric precision.

  11. Ultraviolet Radiation in Overcast Sky at the Surface

    Institute of Scientific and Technical Information of China (English)

    自建辉; 王庚辰; 胡非

    2003-01-01

    Based on the analysis of one year of observation data of solar radiation at the ground in Beijing in 1990, a simple empirical formula for calculating UV radiation in overcast sky is established. The formula is Quv/Quv0 = A1S + A0, where Quv and Quvo are monthly mean daily sums of UV exposure in overcast sky and clear sky, respectively. S is the daily sunshine hours. The calculated results agree well with the observed. The maximum and minimum relative biases are 9.9% and 0.1%, respectively, and the yearly relative bias is 2.9%. The ratio of ultraviolet radiation of overcast sky to clear sky in 1990 is between 44.6% and 61.8%, and the yearly average is 53.9%. Thus, almost half of the UV energy is lost in the atmosphere in overcast sky in 1990.

  12. All Sky Imager Network for Science and Education

    Science.gov (United States)

    Bhatt, A.; Kendall, E. A.; Zalles, D. R.; Baumgardner, J. L.; Marshall, R. A.; Kaltenbacher, E.

    2012-12-01

    A new all sky imager network for space weather monitoring and education outreach has been developed by SRI International. The goal of this program is to install sensitive, low-light all-sky imagers across the continental United States to observe upper atmospheric airglow and aurora in near real time. While aurora borealis is often associated with the high latitudes, during intense geomagnetic storms it can extend well into the continental United States latitudes. Observing auroral processes is instrumental in understanding the space weather, especially in the times of increasing societal dependence on space-based technologies. Under the THEMIS satellite program, Canada has installed a network of all-sky imagers across their country to monitor aurora in real-time. However, no comparable effort exists in the United States. Knowledge of the aurora and airglow across the entire United States in near real time would allow scientists to quickly assess the impact of a geomagnetic storm in concert with data from GPS networks, ionosondes, radars, and magnetometers. What makes this effort unique is that we intend to deploy these imagers at high schools across the country. Selected high-schools will necessarily be in rural areas as the instrument requires dark night skies. At the commencement of the school year, we plan to give an introductory seminar on space weather at each of these schools. Science nuggets developed by SRI International in collaboration with the Center for GeoSpace Studies and the Center for Technology in Learning will be available for high school teachers to use during their science classes. Teachers can use these nuggets as desired within their own curricula. We intend to develop a comprehensive web-based interface that will be available for students and scientific community alike to observe data across the network in near real time and also to guide students towards complementary space weather data sets. This interface will show the real time extent of

  13. Seeing the Sky through Hubble's Eye: The COSMOS SkyWalker

    Science.gov (United States)

    Jahnke, K.; Sánchez, S. F.; Koekemoer, A.

    2006-08-01

    Large, high-resolution space-based imaging surveys produce a volume of data that is difficult to present to the public in a comprehensible way. While megapixel-sized images can still be printed out or downloaded via the World Wide Web, this is no longer feasible for images with 109 pixels (e.g., the Hubble Space Telescope Advanced Camera for Surveys [ACS] images of the Galaxy Evolution from Morphology and SEDs [GEMS] project) or even 1010 pixels (for the ACS Cosmic Evolution Survey [COSMOS]). We present a Web-based utility called the COSMOS SkyWalker that allows viewing of the huge ACS image data set, even through slow Internet connections. Using standard HTML and JavaScript, the application successively loads only those portions of the image at a time that are currently being viewed on the screen. The user can move within the image by using the mouse or interacting with an overview image. Using an astrometrically registered image for the COSMOS SkyWalker allows the display of calibrated world coordinates for use in science. The SkyWalker ``technique'' can be applied to other data sets. This requires some customization, notably the slicing up of a data set into small (e.g., 2562 pixel) subimages. An advantage of the SkyWalker is the use of standard Web browser components; thus, it requires no installation of any software and can therefore be viewed by anyone across many operating systems.

  14. EXPLORING THE VARIABLE SKY WITH LINEAR. I. PHOTOMETRIC RECALIBRATION WITH THE SLOAN DIGITAL SKY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Sesar, Branimir [Division of Physics, Mathematics and Astronomy, Caltech, Pasadena, CA 91125 (United States); Stuart, J. Scott [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA 02420-9108 (United States); Ivezic, Zeljko; Morgan, Dylan P.; Becker, Andrew C. [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Wozniak, Przemyslaw [Los Alamos National Laboratory, Los Alamos, NM 87545-0001 (United States)

    2011-12-15

    We describe photometric recalibration of data obtained by the asteroid survey LINEAR. Although LINEAR was designed for astrometric discovery of moving objects, the data set described here contains over 5 billion photometric measurements for about 25 million objects, mostly stars. We use Sloan Digital Sky Survey (SDSS) data from the overlapping {approx}10,000 deg{sup 2} of sky to recalibrate LINEAR photometry and achieve errors of 0.03 mag for sources not limited by photon statistics with errors of 0.2 mag at r {approx} 18. With its 200 observations per object on average, LINEAR data provide time domain information for the brightest four magnitudes of the SDSS survey. At the same time, LINEAR extends the deepest similar wide-area variability survey, the Northern Sky Variability Survey, by 3 mag. We briefly discuss the properties of about 7000 visually confirmed periodic variables, dominated by roughly equal fractions of RR Lyrae stars and eclipsing binary stars, and analyze their distribution in optical and infrared color-color diagrams. The LINEAR data set is publicly available from the SkyDOT Web site.

  15. The night-sky at the Calar Alto Observatory II: The sky at the near infrared

    CERN Document Server

    Sánchez, S F; Aceituno, J; Cristobal, D; Perea, J; Alves, J

    2008-01-01

    We present here the characterization of the night sky-brightness at the near-infrared, the telescope seeing, and the fraction of useful time at the Calar Alto observatory. For this study we have collected a large dataset comprising 7311 near-infrared images taken regularly along the last four years for the ALHAMBRA survey (J, H and Ks-bands), together with a more reduced dataset of additional near-infrared images taken for the current study. In addition we collected the information derived by the meteorological station at the observatory during the last 10 years, together with the results from the cloud sensor for the last ~2 years. We analyze the dependency of the near-infrared night sky-brightness with the airmass and the seasons, studying its origins and proposing a zenithal correction. A strong correlation is found between the night sky-brightness in the Ks-band and the air temperature, with a gradient of ~ -0.08 mag per 1 C degree. The typical (darkest) night sky-brightness in the J, H and Ks-band are 15...

  16. Study of Lemon Yellow and Sunset Yellow in Adulterated Rhizoma Belamcandae%射干伪品中柠檬黄与日落黄的研究

    Institute of Scientific and Technical Information of China (English)

    王祥红; 谢培山

    2012-01-01

    Objective; To identify and assay of watersoluble dyestuff-lemon yellow and sunset yellow in Adulterated Rhizoma Belamcandae. Method; Use TLC for iddentification and HPLC-DAD for iddentification and assay lemon yellow and sunset yellow. Result; Both TLC and HPLC-DAD can identify lemon yellow and sunset yellow in Adulterated Rhizoma Belamcandae, and HPLC detection indicate the content of lemon yellow between 0. 11-0. 37 g·kg-1, and sunset yellow between 0. 04-0. 11 g·kg-1. Conclusion; Staining Iridis kectori khizoma or other adulterants with lemon yellow and sunset yellow as Rhizoma Belamcandae for sales is not only unnecessary, but also increase unsafe factors in clinic. It is necessary to pay attention to about this by relative medicine researcher and manufactory.%目的:鉴别并测定伪品射干中水溶性色素柠檬黄与日落黄.方法:采用薄层色谱法和高效液相色谱法二极管陈列检测鉴别并定量测定样品中的柠檬黄与日落黄.结果:伪品射干中可检出柠檬黄与日落黄,HPLC法测定柠檬黄含量为0.11 ~0.37 g·kg-1,日落黄含量为0.04 ~0.11 g·kg-1.结论:以川射干或其他伪品用柠檬黄与日落黄染色作为射干销售,即无必要,又曾加临床使用不安全因素,值得相关药品研究与生产单位注意.

  17. Condensation of Self-Assembled Lyotropic Chromonic Liquid Crystal Sunset Yellow in Aqueous Solutions Crowded with Polyethylene Glycol and Doped with Salt

    Energy Technology Data Exchange (ETDEWEB)

    Park, Heung-Shik; Kang, Shin-Woong; Tortora, Luana; Kumar, Satyendra; Lavrentovich, Oleg D. (Chonbuk); (Kent)

    2012-10-10

    We use optical and fluorescence microscopy, densitometry, cryo-transmission electron microscopy (cryo-TEM), spectroscopy, and synchrotron X-ray scattering to study the phase behavior of the reversible self-assembled chromonic aggregates of an anionic dye Sunset Yellow (SSY) in aqueous solutions crowded with an electrically neutral polymer polyethylene glycol (PEG) and doped with the salt NaCl. PEG causes the isotropic SSY solutions to condense into a liquid-crystalline region with a high concentration of SSY aggregates, coexisting with a PEG-rich isotropic (I) region. PEG added to the homogeneous nematic (N) phase causes separation into the coexisting N and I domains; the SSY concentration in the N domains is higher than the original concentration of PEG-free N phase. Finally, addition of PEG to the highly concentrated homogeneous N phase causes separation into the coexisting columnar hexagonal (C) phase and I phase. This behavior can be qualitatively explained by the depletion (excluded volume) effects that act at two different levels: at the level of aggregate assembly from monomers and short aggregates and at the level of interaggregate packing. We also show a strong effect of a monovalent salt NaCl on phase diagrams that is different for high and low concentrations of SSY. Upon the addition of salt, dilute I solutions of SSY show appearance of the condensed N domains, but the highly concentrated C phase transforms into a coexisting I and N domains. We suggest that the salt-induced screening of electric charges at the surface of chromonic aggregates leads to two different effects: (a) increase of the scission energy and the contour length of aggregates and (b) decrease of the persistence length of SSY aggregates.

  18. The sixth data release of the Sloan Digital Sky Survey

    OpenAIRE

    Adelman-McCarthy, Jennifer K.; Agüeros, Marcel A.; Allam, Sahar S.; Prieto, Carlos Allende; Anderson, Kurt S. J.; Anderson, Scott F.; Annis, James; Bahcall, Neta A.; Bailer-Jones, C. A. L.; Baldry, Ivan K.; Barentine, J. C.; Bassett, Bruce A.; Becker, Andrew C.; Beers, Timothy C.; Bell, Eric F.

    2008-01-01

    This paper describes the Sixth Data Release of the Sloan Digital Sky Survey. With this data release, the imaging of the northern Galactic cap is now complete. The survey contains images and parameters of roughly 287 million objects over 9583 deg^2, including scans over a large range of Galactic latitudes and longitudes. The survey also includes 1.27 million spectra of stars, galaxies, quasars, and blank sky (for sky subtraction) selected over 7425 deg^2. This release includes much more stella...

  19. The VLA Low-frequency Sky Survey

    CERN Document Server

    Cohen, A S; Cotton, W D; Kassim, N E; Lazio, T J W; Perley, R A; Condon, J J; Erickson, W C

    2007-01-01

    The Very Large Array (VLA) Low-frequency Sky Survey (VLSS) has imaged 95% of the 3*pi sr of sky north of declination = -30 degrees at a frequency of 74 MHz (4 meter wavelength). The resolution is 80" (FWHM) throughout, and the typical RMS noise level is ~0.1 Jy/beam. The typical point-source detection limit is 0.7 Jy/beam and so far nearly 70,000 sources have been catalogued. This survey used the 74 MHz system added to the VLA in 1998. It required new imaging algorithms to remove the large ionospheric distortions at this very low frequency throughout the entire ~11.9 degree field of view. This paper describes the observation and data reduction methods used for the VLSS and presents the survey images and source catalog. All of the calibrated images and the source catalog are available online (http://lwa.nrl.navy.mil/VLSS) for use by the astronomical community.

  20. Sky monitoring with ARGO-YBJ

    CERN Document Server

    Vernetto, S; Zhang, J L

    2009-01-01

    A sky monitoring at gamma ray energy E > 0.6 TeV has been performed by the full coverage Extensive Air Shower detector ARGO-YBJ, located in Tibet at 4300 m of altitude. We monitored 135 galactic and extragalactic gamma ray sources in the sky declination band from -10 to +70 degrees for 424 days, detecting the Crab Nebula and Mrk421 with a significance respectively of 7.0 and 8.0 standard deviations. For a set of 11 AGNs known to emit in the TeV energy range, the search has been performed in time scales of 1, 10 and 30 days in order to study possible flaring activities. Significant emissions has been observed from Mrk421 in the time scales of 10 and 30 days, during June and March 2008, when the source had a strong activity also observed in the X-rays waveband. The analysis of the background has revealed the existence of a significant excess of the CR flux in two localized regions of angular size 10-30 degrees, in agreement with previous indications.

  1. Deep sky observing an astronomical tour

    CERN Document Server

    Coe, Steven R

    2016-01-01

    This updated second edition has all of the information needed for your successful forays into deep sky observing. Coe uses his years of experience to give detailed practical advice about how to find the best observing site, how to make the most of the time spent there, and what equipment and instruments to take along. There are comprehensive lists of deep sky objects of all kinds, along with Steve's own observations describing how they look through telescopes with apertures ranging from 4 inches to 36 inches (0.1 - 0.9 meters). Binocular observing also gets its due, while the lists of objects have been amended to highlight only the best targets. A new index makes finding targets easier than ever before, while the selection of viewing targets has been revised from the first edition. Most of all, this book is all about how to enjoy astronomy. The author's enthusiasm and sense of wonder shine through every page as he invites you along on a tour of some of the most beautiful and fascinating sites in the deep ...

  2. New SETI Sky Surveys for Radio Pulses

    CERN Document Server

    Siemion, Andrew; McMahon, Peter; Korpela, Eric; Werthimer, Dan; Anderson, David; Bower, Geoff; Cobb, Jeff; Foster, Griffin; Lebofsky, Matt; van Leeuwen, Joeri; Mallard, William; Wagner, Mark

    2008-01-01

    Berkeley conducts 7 SETI programs at IR, visible and radio wavelengths. Here we review two of the newest efforts, Astropulse and Fly's Eye. A variety of possible sources of microsecond to millisecond radio pulses have been suggested in the last several decades, among them such exotic events as evaporating primordial black holes, hyper-flares from neutron stars, emissions from cosmic strings or perhaps extraterrestrial civilizations, but to-date few searches have been conducted capable of detecting them. We are carrying out two searches in hopes of finding and characterizing these uS to mS time scale dispersed radio pulses. These two observing programs are orthogonal in search space; the Allen Telescope Array's (ATA) "Fly's Eye" experiment observes a 100 square degree field by pointing each 6m ATA antenna in a different direction; by contrast, the Astropulse sky survey at Arecibo is extremely sensitive but has 1/3,000 of the instantaneous sky coverage. Astropulse's multibeam data is transferred via the interne...

  3. COSMO-SkyMed and GIS applications

    Science.gov (United States)

    Milillo, Pietro; Sole, Aurelia; Serio, Carmine

    2013-04-01

    Geographic Information Systems (GIS) and Remote Sensing have become key technology tools for the collection, storage and analysis of spatially referenced data. Industries that utilise these spatial technologies include agriculture, forestry, mining, market research as well as the environmental analysis . Synthetic Aperture Radar (SAR) is a coherent active sensor operating in the microwave band which exploits relative motion between antenna and target in order to obtain a finer spatial resolution in the flight direction exploiting the Doppler effect. SAR have wide applications in Remote Sensing such as cartography, surface deformation detection, forest cover mapping, urban planning, disasters monitoring , surveillance etc… The utilization of satellite remote sensing and GIS technology for this applications has proven to be a powerful and effective tool for environmental monitoring. Remote sensing techniques are often less costly and time-consuming for large geographic areas compared to conventional methods, moreover GIS technology provides a flexible environment for, analyzing and displaying digital data from various sources necessary for classification, change detection and database development. The aim of this work si to illustrate the potential of COSMO-SkyMed data and SAR applications in a GIS environment, in particular a demostration of the operational use of COSMO-SkyMed SAR data and GIS in real cases will be provided for what concern DEM validation, river basin estimation, flood mapping and landslide monitoring.

  4. Intercomparisons of Nine Sky Brightness Detectors

    Directory of Open Access Journals (Sweden)

    Henk Spoelstra

    2011-10-01

    Full Text Available Nine Sky Quality Meters (SQMs have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across the Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between ±14%. Individual night time sums range from −16% to +20%. Intercalibration reduces this to 0.5%, and −7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 ± 0.003 mcd/m2 on 12 April, and the largest value was 5.94 ± 0.03 mcd/m2 on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.

  5. Sky Mining - Application to Photomorphic Redshift Estimation

    Science.gov (United States)

    Nayak, Pragyansmita

    The field of astronomy has evolved from the ancient craft of observing the sky. In it's present form, astronomers explore the cosmos not just by observing through the tiny visible window used by our eyes, but also by exploiting the electromagnetic spectrum from radio waves to gamma rays. The domain is undoubtedly at the forefront of data-driven science. The data growth rate is expected to be around 50%--100% per year. This data explosion is attributed largely to the large-scale wide and deep surveys of the different regions of the sky at multiple wavelengths (both ground and space-based surveys). This dissertation describes the application of machine learning methods to the estimation of galaxy redshifts leveraging such a survey data. Galaxy is a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space. Our view of the universe is closely tied to our understanding of galaxy formation. Thus, a better understanding of the relative location of the multitudes of galaxies is crucial. The position of each galaxy can be characterized using three coordinates. Right Ascension (ra) and Declination (dec) are the two coordinates that locate the galaxy in two dimensions on the plane of the sky. It is relatively straightforward to measure them. In contrast, fixing the third coordinate that is the galaxy's distance from the observer along the line of sight (redshift 'z') is considerably more challenging. "Spectroscopic redshift" method gives us accurate and precise measurements of z. However, it is extremely time-intensive and unusable for faint objects. Additionally, the rate at which objects are being identified via photometric surveys far exceeds the rate at which the spectroscopic redshift measurements can keep pace in determining their distance. As the surveys go deeper into the sky, the proportion of faint objects being identified also continues to increase. In order to tackle both these drawbacks increasing in

  6. Using routine meteorological data to derive sky conditions

    Directory of Open Access Journals (Sweden)

    D. Pagès

    Full Text Available Sky condition is a matter of interest for public and weather predictors as part of weather analyses. In this study, we apply a method that uses total solar radiation and other meteorological data recorded by an automatic station for deriving an estimation of the sky condition. The impetus of this work is the intention of the Catalan Meteorological Service (SMC to provide the public with real-time information about the sky condition. The methodology for deriving sky conditions from meteorological records is based on a supervised classification technique called maximum likelihood method. In this technique we first need to define features which are derived from measured variables. Second, we must decide which sky conditions are intended to be distinguished. Some analyses have led us to use four sky conditions: (a cloudless or almost cloudless sky, (b scattered clouds, (c mostly cloudy – high clouds, (d overcast – low clouds. An additional case, which may be treated separately, corresponds to precipitation (rain or snow. The main features for estimating sky conditions are, as expected, solar radiation and its temporal variability. The accuracy of this method of guessing sky conditions compared with human observations is around 70% when applied to four sites in Catalonia (NE Iberian Peninsula. The agreement increases if we take into account the uncertainty both in the automatic classifier and in visual observations.

    Key words. Meteorological and atmospheric dynamics (instruments and techniques; radiative processes – Atmospheric composition and structure (cloud physics and chemistry

  7. Fire in the sky: The southern lights in Indigenous oral traditions

    CERN Document Server

    Hamacher, Duane W

    2015-01-01

    Parts of Australia have been privileged to see dazzling lights in the night sky as the Aurora Australis (known as the southern lights) puts on a show this year. Aurorae are significant in Australian Indigenous astronomical traditions. Aboriginal people associate aurorae with fire, death, blood, and omens, sharing many similarities with Native American communities.

  8. Effect of the position of the visible sky in determining the sky view factor on micrometeorological and human thermal comfort conditions in urban street canyons

    Science.gov (United States)

    Qaid, Adeb; Lamit, Hasanuddin Bin; Ossen, Dilshan Remaz; Rasidi, Mohd Hisyam

    2017-01-01

    Poor daytime and night-time micrometeorological conditions are issues that influence the quality of environmental conditions and can undermine a comfortable human lifestyle. The sky view factor (SVF) is one of the essential physical parameters used to assess the micrometeorological conditions and thermal comfort levels within city streets. The position of the visible sky relative to the path of the sun, in the cardinal and ordinal directions, has not been widely discerned as a parameter that could have an impact on the micrometeorological conditions of urban streets. To investigate this parameter, different urban streets that have a similar SVF value but diverse positions of visible sky were proposed in different street directions intersecting with the path of the sun, namely N-S, NE-SW and NW-SE. The effects of daytime and night-time micrometeorological variables and human thermal comfort variables on the street were investigated by applying ENVI-met V3.1 Beta software. The results show that the position of the visible sky has a greater influence on the street's meteorological and human thermal comfort conditions than the SVF value. It has the ability to maximise or minimise the mean radiation temperature (Tmrt, °C) and the physiological equivalent temperature (PET, °C) at street level. However, the visible sky positioned to the zenith in a NE-SW or N-S street direction and to the SW of a NW-SE street direction achieves the best daytime micrometeorological and thermal comfort conditions. Alternatively, the visible sky positioned to the NE for a NW-SE street direction, to the NW and the zenith for a NE-SW street direction and to the zenith for a N-S street direction reduces the night-time air temperature (Ta, °C). Therefore, SVF and the position of the visible sky relative to the sun's trajectory, in the cardinal and ordinal directions, must be considered during urban street planning to better understand the resultant micrometeorological and human thermal

  9. A distinct layer of the medulla integrates sky compass signals in the brain of an insect.

    Directory of Open Access Journals (Sweden)

    Basil el Jundi

    Full Text Available Mass migration of desert locusts is a common phenomenon in North Africa and the Middle East but how these insects navigate is still poorly understood. Laboratory studies suggest that locusts are able to exploit the sky polarization pattern as a navigational cue. Like other insects locusts detect polarized light through a specialized dorsal rim area (DRA of the eye. Polarization signals are transmitted through the optic lobe to the anterior optic tubercle (AOTu and, finally, to the central complex in the brain. Whereas neurons of the AOTu integrate sky polarization and chromatic cues in a daytime dependent manner, the central complex holds a topographic representation of azimuthal directions suggesting a role as an internal sky compass. To understand further the integration of sky compass cues we studied polarization-sensitive (POL neurons in the medulla that may be intercalated between DRA photoreceptors and AOTu neurons. Five types of POL-neuron were characterized and four of these in multiple recordings. All neurons had wide arborizations in medulla layer 4 and most, additionally, in the dorsal rim area of the medulla and in the accessory medulla, the presumed circadian clock. The neurons showed type-specific orientational tuning to zenithal polarized light and azimuth tuning to unpolarized green and UV light spots. In contrast to neurons of the AOTu, we found no evidence for color opponency and daytime dependent adjustment of sky compass signals. Therefore, medulla layer 4 is a distinct stage in the integration of sky compass signals that precedes the time-compensated integration of celestial cues in the AOTu.

  10. Anthropogenic disruption of the night sky darkness in urban and rural areas.

    Science.gov (United States)

    Bará, Salvador

    2016-10-01

    The growing emissions of artificial light to the atmosphere are producing, among other effects, a significant increase of the night sky brightness (NSB) above its expected natural values. A permanent sensor network has been deployed in Galicia (northwest of Iberian peninsula) to monitor the anthropogenic disruption of the night sky darkness in a countrywide area. The network is composed of 14 detectors integrated in automated weather stations of MeteoGalicia, the Galician public meteorological agency. Zenithal NSB readings are taken every minute and the results are openly available in real time for researchers, interested stakeholders and the public at large through a dedicated website. The measurements allow one to assess the extent of the loss of the natural night in urban, periurban, transition and dark rural sites, as well as its daily and monthly time courses. Two metrics are introduced here to characterize the disruption of the night darkness across the year: the significant magnitude (m1/3) and the moonlight modulation factor (γ). The significant magnitude shows that in clear and moonless nights the zenithal night sky in the analysed urban settings is typically 14-23 times brighter than expected from a nominal natural dark sky. This factor lies in the range 7-8 in periurban sites, 1.6-2.5 in transition regions and 0.8-1.6 in rural and mountain dark sky places. The presence of clouds in urban areas strongly enhances the amount of scattered light, easily reaching amplification factors in excess of 25, in comparison with the light scattered in the same places under clear sky conditions. The periodic NSB modulation due to the Moon, still clearly visible in transition and rural places, is barely notable at periurban locations and is practically lost at urban sites.

  11. Anthropogenic disruption of the night sky darkness in urban and rural areas

    Science.gov (United States)

    Bará, Salvador

    2016-10-01

    The growing emissions of artificial light to the atmosphere are producing, among other effects, a significant increase of the night sky brightness (NSB) above its expected natural values. A permanent sensor network has been deployed in Galicia (northwest of Iberian peninsula) to monitor the anthropogenic disruption of the night sky darkness in a countrywide area. The network is composed of 14 detectors integrated in automated weather stations of MeteoGalicia, the Galician public meteorological agency. Zenithal NSB readings are taken every minute and the results are openly available in real time for researchers, interested stakeholders and the public at large through a dedicated website. The measurements allow one to assess the extent of the loss of the natural night in urban, periurban, transition and dark rural sites, as well as its daily and monthly time courses. Two metrics are introduced here to characterize the disruption of the night darkness across the year: the significant magnitude (m1/3) and the moonlight modulation factor (γ). The significant magnitude shows that in clear and moonless nights the zenithal night sky in the analysed urban settings is typically 14-23 times brighter than expected from a nominal natural dark sky. This factor lies in the range 7-8 in periurban sites, 1.6-2.5 in transition regions and 0.8-1.6 in rural and mountain dark sky places. The presence of clouds in urban areas strongly enhances the amount of scattered light, easily reaching amplification factors in excess of 25, in comparison with the light scattered in the same places under clear sky conditions. The periodic NSB modulation due to the Moon, still clearly visible in transition and rural places, is barely notable at periurban locations and is practically lost at urban sites.

  12. Night Sky Brightness Assessment in Nigeria Using Environmetric and GIS Technique

    Directory of Open Access Journals (Sweden)

    Musa Garba Abdullahi

    2017-02-01

    Full Text Available High anthropogenic activities are rapidly increasing phenomenon and it is assumed to have global implications. In Nigeria, high anthropogenic activities rapidly increase above the standard of the threshold values especially the lighting sources. This increase due to the vastly growing of industries, residential and commercial uses and other sources such as street lighting in urban and semi-urban areas, which can make the night sky brightness in the area above the threshold set for polluted status. The study measures the night sky brightness at the most densely populated urban centers of Nigeria; to estimate and quantify the level of the night sky brightness from the sites nearby the cities of the planned research study. The research monitored the zenith sky brightness from November 2015 to March 2016 using Sky Quality Meter (SQM. However, typical values ranging from 20.14 to 22.00Mag.sqm /arc sec.2 were measured at different sites of the study area. This data recorded in the field was analyzed using Agglomerative Hierarchical Method via Ward’s Methods to cluster our data according to the pollution status of the areas. Result showed three clusters in which class 1 has low pollution; class 2 is moderate while class 3 has the high pollution status. The sites classified in class 3 are more polluted due to the high use of artificial light. However, geographical information system (GIS software was employed to confirm the results obtained from environ-metric technique and concluded that this result is confirmed to be the same. Hence, it illustrated that sites in cluster 1 have an excellent dark location that can be used to build optical observatory stations and other astronomical observations due to their dark sky.

  13. Sunset Song:An Elegy for the Primitive Golden Age%《落日之歌》:原始黄金时代的挽歌

    Institute of Scientific and Technical Information of China (English)

    胡怡君

    2012-01-01

    The representative novel of the twentieth century Scottish writer Lewis Grassic Gibbon,Sunset Song, unfolds a historical scene of the transition from the old to the new in a Scottish village. Based on diffu- sionism and some ideas from the Scottish Enlightenment movement, he shows in the novel a sentimental at- tachment to the primitive golden age and at the same time the hopelessness when witnessing the destruction modern civilization wrought to the old life style. In the novel, the primitive golden age represented by the earth is impinged upon and then replaced by modern civilization. Gibbon's novel thus could be treated as an elegy for the primitive golden age.%20世纪初苏格兰作家刘易斯.格拉斯科·吉本的代表作《落日之歌》展示了一幅苏格兰农村新旧时代交替的图景。他在作品中表达了对原始农耕社会的眷恋之情,同时也表现了在现代工业文明给旧生活方式带来冲击时人的无奈和悲剧。小说中土地代表着吉本眼中的原始黄金时代,土地与现代文明诸多因素的冲突一一反映在小说情节中。整本小说可视为对原始黄金时代的一曲挽歌。

  14. Recognition of Terrestrial Impact Craters with COSMO-SkyMed

    Science.gov (United States)

    Virelli, M.; Staffieri, S.; Battagliere, M. L.; Komatsu, G.; Di Martino, M.; Flamini, E.; Coletta, A.

    2016-08-01

    All bodies having a solid surface, without distinction, show, with greater or lesser evidence, the marks left by the geological processes they undergone during their evolution. There is a geomorphological feature that is evident in all the images obtained by the probes sent to explore our planetary system: impact craters.Craters formed by the impact of small cosmic bodies have dimensions ranging from some meters to hundreds of kilometers. However, for example on the Lunar regolith particles, have been observed also sub- millimeter craters caused by dust impacts. The kinetic energy of the impactor, which velocity is in general of the order of tens km/s, is released in fractions of a second, generally in a explosive way, generating complex phenomena that transform not only the morphology of the surface involved by the impact, but also the mineralogy and crystallography of the impacted material. Even our planet is not immune to these impacts. At present, more than 180 geological structures recognized as of impact origin are known on Earth.In this article, we aim to show how these impact structures on Earth's surface are observed from space. To do this, we used the images obtained by the COSMO-SkyMed satellite constellation.Starting from 2013, ASI proposed, in collaboration with the Astrophysical Observatory of Turin and University D'Annunzio of Chieti, the realization of an Encyclopedic Atlas of Terrestrial Impact Craters using COSMO-SkyMed data that will become the first atlas of all recognized terrestrial impact craters based on images acquired by a X band radar. To observe these impact craters all radar sensor modes have been used, according to the size of the analyzed crater.The project includes research of any new features that could be classified as impact craters and, for the sites whereby it is considered necessary, the implementation of a geological survey on site to validate the observations.In this paper an overview of the Atlas of Terrestrial Impact

  15. Sky surveys of interest for cataclysmic variables

    Science.gov (United States)

    Szkody, Paula

    2016-07-01

    Sky Surveys provide much useful information for finding and understanding catacylsmic variables (CVs). Depending on the length of time the survey runs and the cadence used, the surveys can easily locate novae and dwarf novae based on the amplitude and shape of the light curves. For systems with high inclination or prominent hot spots and periods of hours, some orbital information can be derived from eclipses that are caught or repetitive modulations in the folded light curves. However, in most cases, detailed knowledge of the type of system and its orbital period must come from extended observations at other wavelengths, as most surveys take place in one filter or unfiltered. Currently, we are in the midst of an explosion of recently past, continuing and future plans for sky surveys. The Sloan Digital Sky Survey found about 300 CVs in its Legacy Mode, with small numbers continuing to be added through the extended phases. The CVs were primarily identified through spectroscopic coverage of selected objects from the photometric survey and subsequently found a wide variety of systems (polars, intermediate polars, novalikes, dwarf novae, objects with pulsating white dwarfs) due to spectroscopic differences among these types. The Palomar Transit Factory (PTF), Intermediate PTF and future Zwicky Transient Facilty (ZTF) operate in the same mode of candidate discovery via outbursts followed by spectroscopy for confirmation. The Catalina Real-Time Transient Survey primarily adds dwarf novae that are found from outbursts in the long time span of observations. The Kepler K2 mission operates with a much higher cadence (48-1440 observations/day) but shorter total length (70-80 days) and thus finds CVs through orbital variability as well as those with short outburst intervals. Gaia will provide distances for most of the objects under study, thus locating them in the galaxy. The upcoming Large Synoptic Survey Telescope (LSST) will go much fainter and cover variability on a 10 yr

  16. Ca II Absorbers in the Sloan Digital Sky Survey: Statistics

    CERN Document Server

    Sardane, Gendith M; Rao, Sandhya M

    2014-01-01

    We present the results of a survey for CaII 3934,3969 absorption-line systems culled from ~ 95,000 Sloan Digital Sky Survey (SDSS) Data Release 7 and Data Release 9 quasar spectra. With 435 doublets identified in the catalog, this list is the largest CaII catalog compiled to date, spanning redshifts z = 0.3 A, is n_0=0.017 +/- 0.001. In comparison to MgII surveys, we found that only 3% of MgII systems in the SDSS have CaII, confirming that it is rare to identify CaII in quasar absorption-line surveys. We also report on some preliminary investigations of the nature of the two populations of CaII absorbers, and show that they can likely be distinguished using their MgII properties.

  17. Cysticercal encephalitis presenting with a "Starry Sky" appearance on neuroimaging

    Directory of Open Access Journals (Sweden)

    Tushar B Patil

    2015-01-01

    Full Text Available A lady in her early forties was brought to our hospital in an unconscious state with history of generalized tonic-clonic seizures for last 6 h. She had multiple episodes of seizures in last 4 months, but did not receive any treatment. Relatives also gave a history of fever, headache, and vomiting for last 1 week. Her seizures were controlled with intravenous lorazepam and valproate. Clinical examination revealed a delirious patient with bilateral papilledema, brisk deep tendon reflexes, and extensor plantars. She had aspirated and had bilateral coarse crepitations on chest auscultation. Computed tomography (CT of brain showed multiple small hyperdense calcific lesions extending throughout both the cerebral hemispheres leading to a "starry sky" appearance, suggestive of cysticercal encephalitis. The patient succumbed to progressive aspiration pneumonitis on the 6 th day after hospitalization.

  18. Detection of Cosmic Magnification with the Sloan Digital Sky Survey

    CERN Document Server

    Scranton, R; Richards, G T; Nichol, R C; Myers, A D; Jain, B; Gray, A; Bartelmann, M; Brunner, R J; Connolly, A J; Gunn, J E; Sheth, R K; Bahcall, Neta A; Brinkmann, J; Loveday, J; Schneider, D P; Thakar, A; York, D G; Scranton, Ryan; Menard, Brice; Richards, Gordon T.; Nichol, Robert C.; Myers, Adam D.; Jain, Bhuvnesh; Gray, Alex; Bartelmann, Matthias; Brunner, Robert J.; Connolly, Andrew J.; Gunn, James E.; Sheth, Ravi K.; Bahcall, Neta A.; Brinkman, John; Loveday, Jon; Schneider, Donald P.; Thakar, Aniruddha; York, Donald G.

    2005-01-01

    We present an 8 sigma detection of cosmic magnification measured by the variation of quasar density due to gravitational lensing by foreground large scale structure. To make this measurement we used 3800 square degrees of photometric observations from the Sloan Digital Sky Survey (SDSS) containing \\~200,000 quasars and 13 million galaxies. Our measurement of the galaxy-quasar cross-correlation function exhibits the amplitude, angular dependence and change in sign as a function of the slope of the observed quasar number counts that is expected from magnification bias due to weak gravitational lensing. We show that observational uncertainties (stellar contamination, Galactic dust extinction, seeing variations and errors in the photometric redshifts) are well controlled and do not significantly affect the lensing signal. By weighting the quasars with the number count slope, we combine the cross-correlation of quasars for our full magnitude range and detect the lensing signal at >4 sigma in all five SDSS filters....

  19. The Gamma-ray Sky with Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, D.J. [NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 (United States)

    2013-10-15

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as clusters of galaxies. Some results include a stringent limit on Lorentz invariance violation derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure in the direction of the center of our Galaxy, and strong constraints on some Weakly Interacting Massive Particle (WIMP) models for dark matter.

  20. The 4 Pi Sky Transient Alerts Hub

    CERN Document Server

    Staley, Tim D

    2016-01-01

    We introduce the 4 Pi Sky 'hub', a collection of open data-services and underlying software packages built for rapid, fully automated reporting and response to astronomical transient alerts. These packages build on the mature 'VOEvent' standardized message-format, and aim to provide a decentralized and open infrastructure for handling transient alerts. In particular we draw attention to the initial release of voeventdb, an archive and remote-query service that allows astronomers to make historical queries about transient alerts. By employing spatial filters and web-of-citation lookups, voeventdb enables cross-matching of transient alerts to bring together data from multiple sources, as well as providing a point of reference when planning new follow-up campaigns. We also highlight the recent addition of optical-transient feeds from the ASASSN and GAIA projects to our VOEvent distribution stream. Both the source-code and deployment-scripts which implement these services are freely available and permissively lic...

  1. The Gamma-ray Sky with Fermi

    Science.gov (United States)

    Thompson, David

    2012-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  2. SkyProwler变形无人机

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    如今的无人机行业可用炙手可热来形容。几乎每个月,都会出现一些新概念无人机。近日,在众筹网站Kickstarter上,又出现了一款很有意思的无人机。它就是美国亚利桑那州Krossblade公司正在开发的一款可垂直起降、并能在空中变换造型的无人机SkyProwler。自发起众筹以来,该项目已取得巨大成功,共筹集到超过23万美金。

  3. Integrating paleoecology and genetics of bird populations in two sky island archipelagos

    Directory of Open Access Journals (Sweden)

    Bowen Bonnie S

    2008-06-01

    Full Text Available Abstract Background Genetic tests of paleoecological hypotheses have been rare, partly because recent genetic divergence is difficult to detect and time. According to fossil plant data, continuous woodland in the southwestern USA and northern Mexico became fragmented during the last 10,000 years, as warming caused cool-adapted species to retreat to high elevations. Most genetic studies of resulting 'sky islands' have either failed to detect recent divergence or have found discordant evidence for ancient divergence. We test this paleoecological hypothesis for the region with intraspecific mitochondrial DNA and microsatellite data from sky-island populations of a sedentary bird, the Mexican jay (Aphelocoma ultramarina. We predicted that populations on different sky islands would share common, ancestral alleles that existed during the last glaciation, but that populations on each sky island, owing to their isolation, would contain unique variants of postglacial origin. We also predicted that divergence times estimated from corrected genetic distance and a coalescence model would post-date the last glacial maximum. Results Our results provide multiple independent lines of support for postglacial divergence, with the predicted pattern of shared and unique mitochondrial DNA haplotypes appearing in two independent sky-island archipelagos, and most estimates of divergence time based on corrected genetic distance post-dating the last glacial maximum. Likewise, an isolation model based on multilocus gene coalescence indicated postglacial divergence of five pairs of sky islands. In contrast to their similar recent histories, the two archipelagos had dissimilar historical patterns in that sky islands in Arizona showed evidence for older divergence, suggesting different responses to the last glaciation. Conclusion This study is one of the first to provide explicit support from genetic data for a postglacial divergence scenario predicted by one of the best

  4. Dark Skies, Bright Kids: Year 2

    Science.gov (United States)

    Carlberg, Joleen K.; Johnson, K.; Lynch, R.; Walker, L.; Beaton, R.; Corby, J.; de Messieres, G.; Drosback, M.; Gugliucci, N.; Jackson, L.; Kingery, A.; Layman, S.; Murphy, E.; Richardson, W.; Ries, P.; Romero, C.; Sivakoff, G.; Sokal, K.; Trammell, G.; Whelan, D.; Yang, A.; Zasowski, G.

    2011-01-01

    The Dark Skies, Bright Kids (DSBK) outreach program brings astronomy education into local elementary schools in central Virginia's Southern Albemarle County through an after-school club. Taking advantage of the unusually dark night skies in the rural countryside, DSBK targets economically disadvantaged schools that tend to be underserved due to their rural locale. The goals of DSBK are to foster children's natural curiosity, demonstrate that science is a fun and creative process, challenge students' conceptions of what a scientist is and does, and teach some basic astronomy. Furthermore, DSBK works to assimilate families into students' education by holding family observing nights at the school. Now in its third semester, DSBK has successfully run programs at two schools with very diverse student populations. Working with these students has helped us to revise our activities and to create new ones. A by-product of our work has been the development of lesson plans, complete with learning goals and detailed instructions, that we make publically available on our website. This year we are expanding our repertoire with our new planetarium, which allows us to visualize topics in novel ways and supplements family observing on cloudy nights. The DSBK volunteers have also created a bilingual astronomy artbook --- designed, written, and illustrated by UVa students --- that we will publish and distribute to elementary schools in Virginia. Our book debuted at the last AAS winter meeting, and since then it has been extensively revised and updated with input from many individuals, including parents, professional educators, and a children's book author. Because the club is currently limited to serving a few elementary schools, this book will be part of our efforts to broaden our impact by bringing astronomy to schools we cannot go to ourselves and reaching out to Spanish-speaking communities at the same time.

  5. COSMO-SkyMed Second Generation planner

    Science.gov (United States)

    Covello, Fabio; Scopa, Tiziana; Serva, Stefano; Caltagirone, Francesco; De Luca, Giuseppe Francesco; Pacaccio, Alessandro; Profili, Mario

    2014-10-01

    COSMO-SkyMed Second Generation (CSG) system has been conceived, according to Italian Space Agency (ASI) and Italian Ministry of Defence (It-MoD) requirements, at the twofold objective of ensuring operational continuity to the current constellation (COSMO-SkyMed - CSK), while improving functionality and performances. It is an "end-to-end" Italian Earth Observation Dual-Use (Civilian and Defence) Space System with Synthetic Aperture Radar (SAR) operating in X-Band. CSG mission planning purpose is to fully employ the system resources, shared between partners with very different needs, producing a mission plan that satisfies the higher priority requests and optimizes the overall plan with the remaining requests according to the users programming rights consumption. CSG Mission Planning tool provides new performances in terms of adaptability and flexibility of the planning and scheduling algorithms conceived to select and synchronize data acquisition and downloading activities. CSG planning and scheduling problem is characterized by a large size of research space and a particular structure of technical and managerial constraints that has led to the implementation of innovative design of the planning algorithms based on both priority criteria and saturation of system resources. This approach envisages two scheduling strategies: the rank-based and the optimization-based. The former strategy is firstly applied to the most important request categories, with an associated rank value or priority level; the latter is subsequently applied to the unranked or lower priority requests. This is an iterative dynamic process of finding optimal solutions able to better answer the demanding requirements coming from the needs of heterogeneous users.

  6. Gender Roles and Night-Sky Watching among College Students

    Science.gov (United States)

    Kelly, William E.; McGee, Catherine M.

    2012-01-01

    The present study investigated the relationship between gender roles and night-sky watching in a sample of college students (N=161). The Bem Sex-Role Inventory (BSRI) and the Noctcaelador Inventory (NI) were used to investigate the differences between gender role groups for night-sky watching. The results supported the hypothesis that androgynous…

  7. 76 FR 42704 - Sky River LLC; Notice of Filing

    Science.gov (United States)

    2011-07-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Sky River LLC; Notice of Filing Take notice that, on July 8, 2011, Sky River LLC filed to amend its Open Access Transmission Tariff (OATT) filing, submitted on April 1, 2011...

  8. Gender Roles and Night-Sky Watching among College Students

    Science.gov (United States)

    Kelly, William E.; McGee, Catherine M.

    2012-01-01

    The present study investigated the relationship between gender roles and night-sky watching in a sample of college students (N=161). The Bem Sex-Role Inventory (BSRI) and the Noctcaelador Inventory (NI) were used to investigate the differences between gender role groups for night-sky watching. The results supported the hypothesis that androgynous…

  9. Sky compass orientation in desert locusts – evidence from field and laboratory studies

    Directory of Open Access Journals (Sweden)

    Uwe eHomberg

    2015-12-01

    Full Text Available Locusts are long-range migratory insects. At high population density, immature animals form marching hopper bands while adults take off and form huge swarms of millions of animals. At low population densities animals are solitarious, but likewise migrate, mostly during the night. Numerous studies aimed at predicting locust infestations showed that migrations both as hopper bands and as adults are largely downwind following seasonal shifts of the tropical convergence zone taking the animals to areas of rainfall. Only a few studies provided evidence for active orientation mechanisms, including the involvement of a sun compass. This scarcity of evidence stands in contrast to recent neurobiological data showing sophisticated neuronal adaptations suited for sky compass navigation. These include a special dorsal eye region with photoreceptors suited to analyze the polarization pattern of the sky and a system of topographically arranged sky compass neurons in the central complex of the brain. Laboratory experiments, moreover, demonstrated polarotaxis in tethered flying animals. The discrepancy of these findings call for more rigorous field studies on active orientation mechanisms in locusts. It remains to be shown how locusts use their internal sky compass during mass migrations and what role it plays to guide solitarious locusts in their natural habitat.

  10. Sky Compass Orientation in Desert Locusts-Evidence from Field and Laboratory Studies.

    Science.gov (United States)

    Homberg, Uwe

    2015-01-01

    Locusts are long-range migratory insects. At high population density, immature animals form marching hopper bands while adults take off and form huge swarms of millions of animals. At low population densities animals are solitarious, but likewise migrate, mostly during the night. Numerous studies aimed at predicting locust infestations showed that migrations both as hopper bands and as adults are largely downwind following seasonal shifts of the tropical convergence zone taking the animals to areas of rainfall. Only a few studies provided evidence for active orientation mechanisms, including the involvement of a sun compass. This scarcity of evidence stands in contrast to recent neurobiological data showing sophisticated neuronal adaptations suited for sky compass navigation. These include a special dorsal eye region with photoreceptors suited to analyze the polarization pattern of the sky and a system of topographically arranged sky compass neurons in the central complex of the brain. Laboratory experiments, moreover, demonstrated polarotaxis in tethered flying animals. The discrepancy of these findings call for more rigorous field studies on active orientation mechanisms in locusts. It remains to be shown how locusts use their internal sky compass during mass migrations and what role it plays to guide solitarious locusts in their natural habitat.

  11. The New Progress of the Starry Sky Project of China

    Science.gov (United States)

    Wang, Xiaohua

    2015-08-01

    Since the 28th General Assembly of IAU, the SSPC team made new progress:1. Enhanced the function of the SSPC team-- Established the contact with IAU C50, IUCN Dark Skies Advisory Group, AWB and IDA,and undertakes the work of the IDA Beijing Chapter.-- Got supports from China’s National Astronomical Observatories, Beijing Planetarium, and Shanghai Science and Technology Museum.-- Signed cooperation agreements with Lighting Research Center, English Education Group and law Firm; formed the team force.2. Put forward a proposal to national top institutionThe SSPC submitted the first proposal about dark sky protection to the Chinese People’s Political Consultative Conference.3. Introduced the Criteria and Guideline of dark sky protectionThe SSPC team translated 8 documents of IDA, and provided a reference basis for Chinese dark sky protection.4. Actively establish dark sky places-- Plan a Dark Sky Reserve around Ali astronomical observatory (5,100m elevation) in Tibet. China’s Xinhua News Agency released the news.-- Combining with Hangcuo Lake, a National Natural Reserve and Scenic in Tibet, to plan and establish the Dark Sky Park.-- Cooperated with Shandong Longgang Tourism Group to construct the Dream Sky Theme Park in the suburbs of Jinan city.In the IYL 2015, the SSPC is getting further development:First, make dark sky protection enter National Ecological Strategy of “Beautiful China”. We call on: “Beautiful China” needs “Beautiful Night Sky” China should care the shared starry sky, and left this resource and heritage for children.Second, hold “Cosmic Light” exhibition in Shanghai Science and Technology Museum on August.Third, continue to establish Dark Sky Reserve, Park and Theme Park. We want to make these places become the bases of dark sky protection, astronomical education and ecological tourism, and develop into new cultural industry.Fourth, actively join international cooperation.Now, “Blue Sky, White Cloud and Starry Sky “have become

  12. Night Sky Quality Measurements at the ATA50 Telescope

    Science.gov (United States)

    Er, Hüseyin; Nasiroglu, Ilham; Guney, Yavuz

    2016-07-01

    One of the most important factor affecting the quality of the sky in astronomy is the light pollution (luminance of the night sky). Light pollution, also affects humans and wildlife in many ways. This effect occurs by using the light source of outdoor lighting in the wrong way. Light pollution can be reduced by lighting only what is actually needed, when and where it is needed. In generally, SQM (Sky Quality Meter- Clear Sky Detector) is used to measure this light effect. In this work we present night sky brightness measurements performed at the Atatürk University Astrophysics Research Telescope (ATA50) and the surrounding area, Erzurum, TURKEY. We also discussed the physical impacts of light pollution on science, humans and wildlife.

  13. Day/night whole sky imagers for 24-h cloud and sky assessment: history and overview.

    Science.gov (United States)

    Shields, Janet E; Karr, Monette E; Johnson, Richard W; Burden, Art R

    2013-03-10

    A family of fully automated digital whole sky imagers (WSIs) has been developed at the Marine Physical Laboratory over many years, for a variety of research and military applications. The most advanced of these, the day/night whole sky imagers (D/N WSIs), acquire digital imagery of the full sky down to the horizon under all conditions from full sunlight to starlight. Cloud algorithms process the imagery to automatically detect the locations of cloud for both day and night. The instruments can provide absolute radiance distribution over the full radiance range from starlight through daylight. The WSIs were fielded in 1984, followed by the D/N WSIs in 1992. These many years of experience and development have resulted in very capable instruments and algorithms that remain unique. This article discusses the history of the development of the D/N WSIs, system design, algorithms, and data products. The paper cites many reports with more detailed technical documentation. Further details of calibration, day and night algorithms, and cloud free line-of-sight results will be discussed in future articles.

  14. The Python Sky Model: software for simulating the Galactic microwave sky

    Science.gov (United States)

    Thorne, B.; Dunkley, J.; Alonso, D.; Næss, S.

    2017-08-01

    We present a numerical code to simulate maps of Galactic emission in intensity and polarization at microwave frequencies, aiding in the design of cosmic microwave background experiments. This python code builds on existing efforts to simulate the sky by providing an easy-to-use interface and is based on publicly available data from the WMAP (Wilkinson Microwave Anisotropy Probe) and Planck satellite missions. We simulate synchrotron, thermal dust, free-free and anomalous microwave emission over the whole sky, in addition to the cosmic microwave background, and include a set of alternative prescriptions for the frequency dependence of each component, for example, polarized dust with multiple temperatures and a decorrelation of the signals with frequency, which introduce complexity that is consistent with current data. We also present a new prescription for adding small-scale realizations of these components at resolutions greater than current all-sky measurements. The usefulness of the code is demonstrated by forecasting the impact of varying foreground complexity on the recovered tensor-to-scalar ratio for the LiteBIRD satellite. The code is available at: https://github.com/bthorne93/PySM_public.

  15. Testing sky brightness models against radial dependency: A dense two dimensional survey around the city of Madrid, Spain

    Science.gov (United States)

    Zamorano, J.; Sánchez de Miguel, A.; Ocaña, F.; Pila-Díez, B.; Gómez Castaño, J.; Pascual, S.; Tapia, C.; Gallego, J.; Fernández, A.; Nievas, M.

    2016-09-01

    We present a study of the night sky brightness around the extended metropolitan area of Madrid using Sky Quality Meter (SQM) photometers. The map is the first to cover the spatial distribution of the sky brightness in the centre of the Iberian peninsula. These surveys are necessary to test the light pollution models that predict night sky brightness as a function of the location and brightness of the sources of light pollution and the scattering of light in the atmosphere. We describe the data-retrieval methodology, which includes an automated procedure to measure from a moving vehicle in order to speed up the data collection, providing a denser and wider survey than previous works with similar time frames. We compare the night sky brightness map to the nocturnal radiance measured from space by the DMSP satellite. We find that (i) a single source model is not enough to explain the radial evolution of the night sky brightness, despite the predominance of Madrid in size and population and (ii) that the orography of the region should be taken into account when deriving geo-specific models from general first-principles models. We show the tight relationship between these two luminance measures. This finding sets up an alternative roadmap to extended studies over the globe that will not require the local deployment of photometers or trained personnel.

  16. Classification of Variable Objects in Massive Sky Monitoring Surveys

    Science.gov (United States)

    Woźniak, Przemek; Wyrzykowski, Łukasz; Belokurov, Vasily

    2012-03-01

    The era of great sky surveys is upon us. Over the past decade we have seen rapid progress toward a continuous photometric record of the optical sky. Numerous sky surveys are discovering and monitoring variable objects by hundreds of thousands. Advances in detector, computing, and networking technology are driving applications of all shapes and sizes ranging from small all sky monitors, through networks of robotic telescopes of modest size, to big glass facilities equipped with giga-pixel CCD mosaics. The Large Synoptic Survey Telescope will be the first peta-scale astronomical survey [18]. It will expand the volume of the parameter space available to us by three orders of magnitude and explore the mutable heavens down to an unprecedented level of sensitivity. Proliferation of large, multidimensional astronomical data sets is stimulating the work on new methods and tools to handle the identification and classification challenge [3]. Given exponentially growing data rates, automated classification of variability types is quickly becoming a necessity. Taking humans out of the loop not only eliminates the subjective nature of visual classification, but is also an enabling factor for time-critical applications. Full automation is especially important for studies of explosive phenomena such as γ-ray bursts that require rapid follow-up observations before the event is over. While there is a general consensus that machine learning will provide a viable solution, the available algorithmic toolbox remains underutilized in astronomy by comparison with other fields such as genomics or market research. Part of the problem is the nature of astronomical data sets that tend to be dominated by a variety of irregularities. Not all algorithms can handle gracefully uneven time sampling, missing features, or sparsely populated high-dimensional spaces. More sophisticated algorithms and better tools available in standard software packages are required to facilitate the adoption of

  17. Hunting the Southern Skies with SIMBA

    Science.gov (United States)

    2001-08-01

    First Images from the New "Millimetre Camera" on SEST at La Silla Summary A new instrument, SIMBA ("SEST IMaging Bolometer Array") , has been installed at the Swedish-ESO Submillimetre Telescope (SEST) at the ESO La Silla Observatory in July 2001. It records astronomical images at a wavelength of 1.2 mm and is able to quickly map large sky areas. In order to achieve the best possible sensitivity, SIMBA is cooled to only 0.3 deg above the absolute zero on the temperature scale. SIMBA is the first imaging millimetre instrument in the southern hemisphere . Radiation at this wavelength is mostly emitted from cold dust and ionized gas in a variety of objects in the Universe. Among other, SIMBA now opens exciting prospects for in-depth studies of the "hidden" sites of star formation , deep inside dense interstellar nebulae. While such clouds are impenetrable to optical light, they are transparent to millimetre radiation and SIMBA can therefore observe the associated phenomena, in particular the dust around nascent stars . This sophisticated instrument can also search for disks of cold dust around nearby stars in which planets are being formed or which may be left-overs of this basic process. Equally important, SIMBA may observe extremely distant galaxies in the early universe , recording them while they were still in the formation stage. Various SIMBA images have been obtained during the first tests of the new instrument. The first observations confirm the great promise for unique astronomical studies of the southern sky in the millimetre wavelength region. These results also pave the way towards the Atacama Large Millimeter Array (ALMA) , the giant, joint research project that is now under study in Europe, the USA and Japan. PR Photo 28a/01 : SIMBA image centered on the infrared source IRAS 17175-3544 PR Photo 28b/01 : SIMBA image centered on the infrared source IRAS 18434-0242 PR Photo 28c/01 : SIMBA image centered on the infrared source IRAS 17271-3439 PR Photo 28d/01

  18. SkyDOT (Sky Database for Objects in the Time Domain) A Virtual Observatory for Variability Studies at LANL

    CERN Document Server

    Wozniak, P R; Galassi, M; Priedhorsky, W; Starr, D; Vestrand, W T; White, R; Wren, J

    2002-01-01

    The mining of Virtual Observatories (VOs) is becoming a powerful new method for discovery in astronomy. Here we report on the development of SkyDOT (Sky Database for Objects in the Time domain), a new Virtual Observatory, which is dedicated to the study of sky variability. The site will confederate a number of massive variability surveys and enable exploration of the time domain in astronomy. We discuss the architecture of the database and the functionality of the user interface. An important aspect of SkyDOT is that it is continuously updated in near real time so that users can access new observations in a timely manner. The site will also utilize high level machine learning tools that will allow sophisticated mining of the archive. Another key feature is the real time data stream provided by RAPTOR (RAPid Telescopes for Optical Response), a new sky monitoring experiment under construction at Los Alamos National Laboratory (LANL).

  19. Predicting the sky from 30 MHz to 800 GHz: the extended Global Sky Model

    Science.gov (United States)

    Liu, Adrian

    We propose to construct the extended Global Sky Model (eGSM), a software package and associated data products that are capable of generating maps of the sky at any frequency within a broad range (30 MHz to 800 GHz). The eGSM is constructed from archival data, and its outputs will include not only "best estimate" sky maps, but also accurate error bars and the ability to generate random realizations of missing modes in the input data. Such views of the sky are crucial in the practice of precision cosmology, where our ability to constrain cosmological parameters and detect new phenomena (such as B-mode signatures from primordial gravitational waves, or spectral distortions of the Cosmic Microwave Background; CMB) rests crucially on our ability to remove systematic foreground contamination. Doing so requires empirical measurements of the foreground sky brightness (such as that arising from Galactic synchrotron radiation, among other sources), which are typically performed only at select narrow wavelength ranges. We aim to transcend traditional wavelength limits by optimally combining existing data to provide a comprehensive view of the foreground sky at any frequency within the broad range of 30 MHz to 800 GHz. Previous efforts to interpolate between multi-frequency maps resulted in the Global Sky Model (GSM) of de Oliveira-Costa et al. (2008), a software package that outputs foreground maps at any frequency of the user's choosing between 10 MHz and 100 GHz. However, the GSM has a number of shortcomings. First and foremost, the GSM does not include the latest archival data from the Planck satellite. Multi-frequency models depend crucially on data from Planck, WMAP, and COBE to provide high-frequency "anchor" maps. Another crucial shortcoming is the lack of error bars in the output maps. Finally, the GSM is only able to predict temperature (i.e., total intensity) maps, and not polarization information. With the recent release of Planck's polarized data products, the

  20. Determination of sunset yellow and tartrazine in food samples by combining ionic liquid-based aqueous two-phase system with high performance liquid chromatography.

    Science.gov (United States)

    Sha, Ou; Zhu, Xiashi; Feng, Yanli; Ma, Weixing

    2014-01-01

    We proposed a simple and effective method, by coupling ionic liquid-based aqueous two-phase systems (IL-ATPSs) with high performance liquid chromatography (HPLC), for the analysis of determining tartrazine and sunset yellow in food samples. Under the optimized conditions, IL-ATPSs generated an extraction efficiency of 99% for both analytes, which could then be directly analyzed by HPLC without further treatment. Calibration plots were linear in the range of 0.01-50.0 μg/mL for both Ta and SY. The limits of detection were 5.2 ng/mL for Ta and 6.9 ng/mL for SY. This method proves successful for the separation/analysis of tartrazine and sunset yellow in soft drink sample, candy sample, and instant powder drink and leads to consistent results as obtained from the Chinese national standard method.

  1. Determination of Sunset Yellow and Tartrazine in Food Samples by Combining Ionic Liquid-Based Aqueous Two-Phase System with High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Ou Sha

    2014-01-01

    Full Text Available We proposed a simple and effective method, by coupling ionic liquid-based aqueous two-phase systems (IL-ATPSs with high performance liquid chromatography (HPLC, for the analysis of determining tartrazine and sunset yellow in food samples. Under the optimized conditions, IL-ATPSs generated an extraction efficiency of 99% for both analytes, which could then be directly analyzed by HPLC without further treatment. Calibration plots were linear in the range of 0.01–50.0 μg/mL for both Ta and SY. The limits of detection were 5.2 ng/mL for Ta and 6.9 ng/mL for SY. This method proves successful for the separation/analysis of tartrazine and sunset yellow in soft drink sample, candy sample, and instant powder drink and leads to consistent results as obtained from the Chinese national standard method.

  2. Planck 2013 results. XI. All-sky model of thermal dust emission

    CERN Document Server

    Abergel, A; Aghanim, N; Alina, D; Alves, M I R; Armitage-Caplan, C; Arnaud, M; Ashdown, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartlett, J G; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bobin, J; Bock, J J; Bonaldi, A; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Bridges, M; Bucher, M; Burigana, C; Butler, R C; Cardoso, J -F; Catalano, A; Chamballu, A; Chary, R -R; Chiang, H C; Chiang, L -Y; Christensen, P R; Church, S; Clemens, M; Clements, D L; Colombi, S; Colombo, L P L; Combet, C; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J -M; Désert, F -X; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dupac, X; Efstathiou, G; Enßlin, T A; Eriksen, H K; Falgarone, E; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Galeotta, S; Ganga, K; Ghosh, T; Giard, M; Giardino, G; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Grenier, I A; Gruppuso, A; Guillet, V; Hansen, F K; Hanson, D; Harrison, D; Helou, G; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Huffenberger, K M; Jaffe, A H; Jaffe, T R; Jewell, J; Joncas, G; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Knoche, J; Knox, L; Kunz, M; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Lasenby, A; Laureijs, R J; Lawrence, C R; Leonardi, R; León-Tavares, J; Lesgourgues, J; Levrier, F; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Massardi, M; Matarrese, S; Matthai, F; Mazzotta, P; McGehee, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Osborne, S; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Pasian, F; Patanchon, G; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Popa, L; Poutanen, T; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Reach, W T; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rowan-Robinson, M; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savini, G; Scott, D; Seiffert, M D; Shellard, E P S; Spencer, L D; Starck, J -L; Stolyarov, V; Stompor, R; Sudiwala, R; Sunyaev, R; Sureau, F; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Tavagnacco, D; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Tuovinen, J; Türler, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; Welikala, N; Yvon, D; Zacchei, A; Zonca, A

    2014-01-01

    This paper presents an all-sky model of dust emission from the Planck 857, 545 and 353 GHz, and IRAS 100 micron data. Using a modified black-body fit to the data we present all-sky maps of the dust optical depth, temperature, and spectral index over the 353-3000 GHz range. This model is a tight representation of the data at 5 arcmin. It shows variations of the order of 30 % compared with the widely-used model of Finkbeiner, Davis, and Schlegel. The Planck data allow us to estimate the dust temperature uniformly over the whole sky, providing an improved estimate of the dust optical depth compared to previous all-sky dust model, especially in high-contrast molecular regions. An increase of the dust opacity at 353 GHz, tau_353/N_H, from the diffuse to the denser interstellar medium (ISM) is reported. It is associated with a decrease in the observed dust temperature, T_obs, that could be due at least in part to the increased dust opacity. We also report an excess of dust emission at HI column densities lower than...

  3. Night sky at the Indian Astronomical Observatory during 2000-2008

    CERN Document Server

    Stalin, C S; Sahu, D K; Parihar, P S; Anupama, G C; Bhatt, B C; Prabhu, T P

    2008-01-01

    We present an analysis of the optical night sky brightness and extinction coefficient measurements in UBVRI at the Indian Astronomical Observatory (IAO), Hanle, during the period 2003-2008. They are obtained from an analysis of CCD images acquired at the 2 m Himalayan Chandra Telescope at IAO. Night sky brightness was estimated using 210 HFOSC images obtained on 47 nights and covering the declining phase of solar activity cycle-23. The zenith corrected values of the moonless night sky brightness in mag/square arcsecs are 22.14(U), 22.42(B), 21.28(V), 20.54(R) and 18.86(I) band. This shows that IAO is a dark site for optical observations. No clear dependency of sky brightness with solar activity is found. Extinction values at IAO are derived from an analysis of 1325 images over 58 nights. They are found to be 0.36 in U-band, 0.21 in B-band, 0.12 in V-band, 0.09 in R-band and 0.05 in I-band. On average, extinction during the summer months is slightly larger than that during the winter months. No clear evidence ...

  4. An automated cloud detection method based on green channel of total sky visible images

    Directory of Open Access Journals (Sweden)

    J. Yang

    2015-05-01

    Full Text Available Getting an accurate cloud cover state is a challenging task. In the past, traditional two-dimensional red-to-blue band methods have been widely used for cloud detection in total sky images. By analyzing the imaging principle of cameras, green channel has been selected to replace the 2-D red-to-blue band for total sky cloud detection. The brightness distribution in a total sky image is usually non-uniform, because of forward scattering and Mie scattering of aerosols, which results in increased detection errors in the circumsolar and near-horizon regions. This paper proposes an automatic cloud detection algorithm, "green channel background subtraction adaptive threshold" (GBSAT, which incorporates channel selection, background simulation, computation of solar mask and cloud mask, subtraction, adaptive threshold, and binarization. Several experimental cases show that the GBSAT algorithm is robust for all types of test total sky images and has more complete and accurate retrievals of visual effects than those found through traditional methods.

  5. Retrieval of cloud optical depth from the cloud modification factor (CMF) for overcast skies

    Science.gov (United States)

    Serrano, David; José Marín, María; Esteve, Anna R.; Estellés, Victor; Núñez, Manuel; Utrillas, M. Pilar; Martínez-Lozano, José A.

    2014-05-01

    Clouds generally produce an attenuating effect over solar radiation (up to 80%) that depends, among other characteristics, on the type of the cloud, its optical depth and its distribution in the sky. To analyse the dependence of the atmospheric transmissivity of solar radiation with the cloud optical depth for overcast skies (τ), both in the range of ultraviolet erythemal radiation (UVER) and in the broadband, we have used the cloud optical depths obtained by a minimization process from the irradiation surface measurements. Measurements in the UVER range were obtained by means of a UVB-1 broadband radiometer by Yankee Environmental Systems, with a spectral range of 280 - 400 nm, and in the broadband with a CM-6 pyranometer by Kipp & Zonen, with a spectral range of 310 - 2800 nm. The cloud cover was obtained from cloud sky images, which were acquired at 5 minute intervals using a sky camera by SONA Sieltec Canarias S.L. A CE318 sunphotometer by CIMEL was used in this study for monitoring aerosol optical properties in a vertical column of the atmosphere. Modelled cloud optical depths obtained by the minimization process are iterated until modelled irradiances are equal to or less than 2 percent of the measured value. This study presents the relationship between the cloud optical depths, obtained by the previous minimization method, and an important atmospheric transmissivity factor, the cloud modification factor (CMF). CMF, defined as the ratio between the measured radiation in overcast sky conditions and the calculated radiation for a cloudless sky, provides a first distinction of cloud radiative effects. CMF can be evaluated for different spectral intervals, ultraviolet as well as broadband. For the estimation of CMF, we have calculated cloudless sky irradiance in two different ways: first in a simple way using the empirical expression given by Madronich's equation for UVER range and secondly using the SBDART model for both the UVER and the broadband. Data from

  6. Star-galaxy separation strategies for WISE-2MASS all-sky infrared galaxy catalogues

    Science.gov (United States)

    Kovács, András; Szapudi, István

    2015-04-01

    We combine photometric information of the Wide-Field Infrared Survey Explorer (WISE) and Two Micron All Sky Survey (2MASS) all-sky infrared data bases, and demonstrate how to produce clean and complete galaxy catalogues for future analyses. Adding 2MASS colours to WISE photometry improves star-galaxy separation efficiency substantially at the expense of losing a small fraction of the galaxies. We find that 93 per cent of the WISE objects within W1 training set from the Sloan Digital Sky Survey PhotoObj table with known star-galaxy separation, and determined redshift distribution of our sample from the Galaxy and Mass Assembly spectroscopic survey. Varying the combination of photometric parameters input into our algorithm we show that W1WISE - J2MASS is a simple and effective star-galaxy separator, capable of producing results comparable to the multidimensional SVM classification. We present a detailed description of our star-galaxy separation methods, and characterize the robustness of our tools in terms of contamination, completeness, and accuracy. We explore systematics of the full sky WISE-2MASS galaxy map, such as contamination from moon glow. We show that the homogeneity of the full sky galaxy map is improved by an additional J2MASS galaxy catalogue we present in this paper covers 21 200 deg2 with dusty regions masked out, and has an estimated stellar contamination of 1.2 per cent and completeness of 70.1 per cent among 2.4 million galaxies with zmed ≈ 0.14. WISE-2MASS galaxy maps with well controlled stellar contamination will be useful for spatial statistical analyses, including cross-correlations with other cosmological random fields, such as the cosmic microwave background. The same techniques also yield a statistically controlled sample of stars as well.

  7. Global horizontal irradiance clear sky models : implementation and analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Hansen, Clifford W.; Reno, Matthew J.

    2012-03-01

    Clear sky models estimate the terrestrial solar radiation under a cloudless sky as a function of the solar elevation angle, site altitude, aerosol concentration, water vapor, and various atmospheric conditions. This report provides an overview of a number of global horizontal irradiance (GHI) clear sky models from very simple to complex. Validation of clear-sky models requires comparison of model results to measured irradiance during clear-sky periods. To facilitate validation, we present a new algorithm for automatically identifying clear-sky periods in a time series of GHI measurements. We evaluate the performance of selected clear-sky models using measured data from 30 different sites, totaling about 300 site-years of data. We analyze the variation of these errors across time and location. In terms of error averaged over all locations and times, we found that complex models that correctly account for all the atmospheric parameters are slightly more accurate than other models, but, primarily at low elevations, comparable accuracy can be obtained from some simpler models. However, simpler models often exhibit errors that vary with time of day and season, whereas the errors for complex models vary less over time.

  8. Causality and skies: is non-refocussing necessary?

    CERN Document Server

    Bautista, A; Lafuente, J

    2014-01-01

    It is shown that if $M$ is a strongly causal free of naked singularities space-time, then its causal structure is completely characterized by a partial order in the space of skies defined by means of a class non-negative Legendrian isotopies. It is also proved that such partial order is determined by the class of future causal celestial curves, that is, curves in the space of light rays which are tangent to skies and such that they determine non-negative sky-Legendrian isotopies. It will also be proved that the space of skies $\\Sigma$ equipped with Low's (or reconstructive) topology is homeomorphic and diffeomorphic to $M$ under the only additional assumption that $M$ separates skies, that is, that different points determine different skies. The sky-separating property of $M$ being weaker than the "non-refocussing" property encountered in the previous literature is sharp and the previous result provides the answer to the question of what is the class of space-times whose causal structure, topology and differe...

  9. All Sky Cloud Coverage Monitoring for SONG-China Project

    Science.gov (United States)

    Tian, J. F.; Deng, L. C.; Yan, Z. Z.; Wang, K.; Wu, Y.

    2016-05-01

    In order to monitor the cloud distributions at Qinghai station, a site selected for SONG (Stellar Observations Network Group)-China node, the design of the proto-type of all sky camera (ASC) applied in Xinglong station is adopted. Both hardware and software improvements have been made in order to be more precise and deliver quantitative measurements. The ARM (Advanced Reduced Instruction Set Computer Machine) MCU (Microcontroller Unit) instead of PC is used to control the upgraded version of ASC. A much higher reliability has been realized in the current scheme. Independent of the positions of the Sun and Moon, the weather conditions are constantly changing, therefore it is difficult to get proper exposure parameters using only the temporal information of the major light sources. A realistic exposure parameters for the ASC can actually be defined using a real-time sky brightness monitor that is also installed at the same site. The night sky brightness value is a very sensitive function of the cloud coverage, and can be accurately measured by the sky quality monitor. We study the correlation between the exposure parameter and night sky brightness value, and give the mathematical relation. The images of the all sky camera are inserted into database directly. All sky quality images are archived in FITS format which can be used for further analysis.

  10. Sky luminance distribution in Pamplona (Spain) during the summer period

    Science.gov (United States)

    Torres, J. L.; de Blas, M.; García, A.; Gracia, A.; de Francisco, A.

    2010-04-01

    In this work the outdoor daylight conditions in Pamplona (South Europe) during the summer period have been studied. The selected sky type (from fifteen standards) at a given moment is the one exhibiting the lowest RMSD when comparing the theoretical and experimental luminance distributions in the sky hemisphere. Two year data of luminance distribution registered every 10 min in 145 positions of the sky hemisphere have been used for selecting the sky type. The most frequent sky type in Pamplona is V.5 (cloudless polluted with a broad solar corona), with an occurrence of 29.5%. This result coincides with the one observed in a previous study in Athens. Six types of sky (V.5, IV.4, III.4, III.3, V.4 y II.2) out of the fifteen standards become practically the 80% of all the studied ones. Regarding a possible use in daylight climate studies, the frequency of occurrence of the fifteen types of sky for fourteen solar elevation intervals has been included.

  11. Sky Background Variability Measured on Maunakea at Gemini North Observatory

    Science.gov (United States)

    Smith, Adam B.; Roth, Katherine; Stephens, Andrew W.

    2016-01-01

    Gemini North has recently implemented a Quality Assessment Pipeline (QAP) that automatically reduces images in realtime to determine sky condition quantities, including background sky brightness from the optical to near-infrared. Processing archived images through the QAP and mining the results allows us to look for trends and systematic issues with the instruments and optics during the first decade of Gemini.Here we present the results of using the QAP calculated values to quantify how airglow affects the background sky brightness of images taken with Gemini's imaging instruments, GMOS and NIRI, as well as searching for other factors that may cause changes in the sky brightness. By investigating the dependence of measured sky brightness as a function of a variety of variables, including time after twilight, airmass, season, distance from the moon, air temperature, etc., we quantify the effect of sky brightness and its impact on the sensitivity of Gemini optical and near-infrared imaging data. These measurements will be used to determine new sky background relationships for Maunakea, and to improve the Gemini Integration Time Calculators (ITCs).

  12. Height-dependent sunrise and sunset: Effects and implications of the varying times of occurrence for local ionospheric processes and modelling

    Science.gov (United States)

    Verhulst, Tobias G. W.; Stankov, Stanimir M.

    2017-10-01

    It is well established that the sunrise and sunset periods are of particular importance to ionospheric research and modelling because of the rapid changes in the ionospheric plasma density, temperature, and dynamics. In particular, the sharp increase in the ionisation following sunrise results in a quick increase in the ionospheric peak density, NmF2 , and a decrease in the peak height, hmF2 . Changes in plasma temperature, scale height and transport processes add further complexity which makes it difficult to investigate and model the ionospheric behaviour during this transitional period from night to day. One of the aspects contributing to this difficulty is that not all ionospheric altitudes are exposed to the first sunlight of the day at the same time. During sunrise, the upper part of the ionosphere is illuminated prior to the lower part which is still in the dark. The boundary between sunlit and dark regions moves downwards until it reaches the surface of the Earth, which is commonly taken as the moment of sunrise at certain geographical coordinates. This means that the sunrise at surface level does not occur until after the entire ionosphere has been illuminated. During sunset, the same process happens in reverse order. This paper addresses the issue of these altitude-dependent times of sunrise and sunset and reports on our study of some of the effects on the diurnal variations in the ionospheric characteristics.

  13. MUSE dream conclusion: the sky verdict

    Science.gov (United States)

    Caillier, P.; Accardo, M.; Adjali, L.; Anwand, H.; Bacon, R.; Boudon, D.; Capoani, L.; Daguisé, E.; Dupieux, M.; Dupuy, C.; Francois, M.; Glindemann, A.; Gojak, D.; Gonté, F.; Haddad, N.; Hansali, G.; Hahn, T.; Jarno, A.; Kelz, A.; Koehler, C.; Kosmalski, J.; Laurent, F.; Larrieu, M.; Lizon, J.-L.; Loupias, M.; Manescau, A.; Migniau, J.-E.; Monstein, C.; Nicklas, H.; Parès, L.; Pécontal-Rousset, A.; Piqueras, L.; Reiss, R.; Remillieux, A.; Renault, E.; Rupprecht, G.; Streicher, O.; Stuik, R.; Valentin, H.; Vernet, J.; Weilbacher, P.; Zins, G.

    2014-08-01

    MUSE (Multi Unit Spectroscopic Explorer) is a second generation instrument built for ESO (European Southern Observatory). The MUSE project is supported by a European consortium of 7 institutes. After the finalisation of its integration in Europe, the MUSE instrument has been partially dismounted and shipped to the VLT (Very Large Telescope) in Chile. From October 2013 till February 2014, it has then been reassembled, tested and finally installed on the telescope its final home. From there it collects its first photons coming from the outer limit of the visible universe. This critical moment when the instrument finally meets its destiny is the opportunity to look at the overall outcome of the project and the final performance of the instrument on the sky. The instrument which we dreamt of has become reality. Are the dreamt performances there as well? These final instrumental performances are the result of a step by step process of design, manufacturing, assembly, test and integration. Now is also time to review the path opened by the MUSE project. What challenges were faced during those last steps, what strategy, what choices did pay off? What did not?

  14. MUSE from Europe to the Chilean Sky

    Science.gov (United States)

    Caillier, P.; Accardo, Mateo; Adjali, L.; Anwand, H.; Bacon, R.; Boudon, D.; Capoani, L.; Daguisé, E.; Dupieux, M.; Dupuy, C.; François, M.; Glindemann, A.; Gojak, D.; Gonté, F.; Haddad, N.; Hansali, G.; Hahn, T.; Jarno, A.; Kelz, A.; Koehler, Kristof; Kosmalski, Johan; Laurent, F.; Larrieu, M.; Lizon, J.-L.; Loupias, M.; Manescau, A.; Migniau, J. E.; Monstein, C.; Nicklas, H.; Parès, L.; Pécontal-Rousset, A.; Piqueras, L.; Reiss, R.; Remillieux, A.; Renault, E.; Rupprecht, G.; Streicher, O.; Stuik, R.; Valentin, H.; Vernet, J.; Weilbacher, P.; Zins, G.

    2014-07-01

    MUSE (Multi Unit Spectroscopic Explorer) is a second generation instrument, built for ESO (European Southern Observatory) and dedicated to the VLT (Very Large Telescope). This instrument is an innovative integral field spectrograph (1x1 arcmin2 Field of View), operating in the visible wavelength range, from 465 nm to 930 nm. The MUSE project is supported by a European consortium of 7 institutes. After the finalisation of its integration and test in Europe validated by its Preliminary Acceptance in Europe, the MUSE instrument has been partially dismounted and shipped to the VLT (Very Large Telescope) in Chile. From October 2013 till February 2014, it has then been reassembled, tested and finally installed on the telescope its final home. From there it will collect its first photons coming from the outer limit of the visible universe. To come to this achievement, many tasks had to be completed and challenges overcome. These last steps in the project life have certainly been ones of the most critical. Critical in terms of risk, of working conditions, of operational constrains, of schedule and finally critical in terms of outcome: The first light and the final performances of the instrument on the sky.

  15. Splitting neutrino masses and showering into Sky

    CERN Document Server

    Fargion, D; Iacovelli, M; Lanciano, O; Oliva, P; De Lucentini, P G S; Grossi, M; De Santis, M

    2006-01-01

    Neutrino masses might be as light as a few time the atmospheric neutrino mass splitting. High Energy ZeV cosmic neutrinos (in Z-Showering model) might hit relic ones at each mass in different resonance energies in our nearby Universe. This non-degenerated density and energy must split UHE Z-boson secondaries (in Z-Burst model) leading to multi injection of UHECR nucleons within future extreme AUGER energy. Secondaries of Z-Burst as neutral gamma, below a few tens EeV are better surviving local GZK cut-off and they might explain recent Hires BL-Lac UHECR correlations at small angles. A different high energy resonance must lead to Glashow's anti-neutrino showers while hitting electrons in matter. In air, Glashow's anti-neutrino showers lead to collimated and directional air-showers offering a new Neutrino Astronomy. At greater energy around PeV, Tau escaping mountains and Earth and decaying in flight are effectively showering in air sky. These Horizontal showering is splitting by geomagnetic field in forked sha...

  16. Blue Sky Birds Come to the World

    Directory of Open Access Journals (Sweden)

    Bura Sabiha Kelek

    2015-06-01

    Full Text Available The New Supply System comes to all fields for logistics.Drone is an unmanned vehicle for loading and unloading packages.Perhaps we can imagine it as a ‘’blue sky bird’’. This new trend has three important impacts that are determined by technoligical capabilities, ,regularity pressure, and public acceptance so that it will be dealed within current powers and circumstances. This kind of vehicles are used in different capacities, such as multicopter,drone or robot.Logistics’ issues are interested in short-term delivery systems for customer satisfaction but all developments go through GPS so it is based on 21st century technological developments, which have been tested on a short-term basis and will be expected to be of use in 2 years. The purpose of this research is to give lead to researchers information about risk and the advantages of using the technology in this manner.Some advantages and disadvantages ,schedules’ problems in the system will be identifed.

  17. All-sky search of NAUTILUS data

    Energy Technology Data Exchange (ETDEWEB)

    Astone, P [Istituto Nazionale di Fisica Nucleare INFN, Rome (Italy); Bassan, M; Coccia, E; D' Antonio, S; Minenkov, Y; Modena, I [University of Rome ' Tor Vergata' and INFN, Rome II (Italy); Bonifazi, P [IFSI-CNR and INFN, Rome (Italy); Borkowski, K M [Centre of Astronomy, Nicolaus Copernicus University, Torun (Poland); Budzynski, R J [Department of Physics, Warsaw University, Warsaw (Poland); Chincarini, A [Istituto Nazionale di Fisica Nucleare INFN, Genova (Italy); Emilio, M Di Paolo [INFN, Laboratori Nazionali del Gran Sasso, Assergi, L' Aquila (Italy); Fafone, V; Giordano, G; Marini, A [Istituto Nazionale di Fisica Nucleare INFN, Frascati (Italy); Frasca, S [University of Rome ' La Sapienza' and INFN, Rome (Italy); Foffa, S; Maggiore, M [Dep. de Phys. Theorique, Universite de Geneve, Geneve (Switzerland); Jaranowski, P [Faculty of Physics, University of Bialystok, Bialystok (Poland); Kondracki, W; Krolak, A [Institute of Mathematics, Polish Academy of Sciences, Warsaw (Poland)], E-mail: krolak@impan.gov.pl (and others)

    2008-09-21

    A search for periodic gravitational-wave signals from isolated neutron stars in the NAUTILUS detector data is presented. We have analyzed half a year of data over the frequency band (922.2; 923.2) Hz, the spindown range ( - 1.463 x 10{sup -8}; 0) Hz/s and over the entire sky. We have divided the data into two day stretches and we have analyzed each stretch coherently using matched filtering. We have imposed a low threshold for the optimal detection statistic to obtain a set of candidates that are further examined for coincidences among various data stretches. For some candidates we have also investigated the change of the signal-to-noise ratio when we increase the observation time from 2 to 4 days. Our analysis has not revealed any gravitational-wave signals. Therefore we have imposed upper limits on the dimensionless gravitational-wave amplitude over the parameter space that we have searched. Depending on frequency, our upper limit ranges from 3.4 x 10{sup -23} to 1.3 x 10{sup -22}. We have attempted a statistical verification of the hypotheses leading to our conclusions. We estimate that our upper limit is accurate to within 18%.

  18. Lighting up the sky for CERN's anniversary

    CERN Multimedia

    2004-01-01

    For CERN's Golden Jubilee, the Canton of Geneva, supported by the Pays de Gex local authorities, lit up eight points around the LHC ring. On the date of CERN's fiftieth anniversary, 29 September 2004, the Organization's Host State authorities gave the Laboratory a gift of light. As night fell, twenty-four powerful floodlights blazed into the night sky from the eight access points to the future LHC. For the many spectators gathered at a special vantage point above the village of Crozet, these beams emanating from the valley floor marked out the locations of the access shafts around the 27-km of the LHC tunnel.The event was organised by the Department of Justice, Police and Security of the Canton of Geneva, with the participation of the Crozet local council and support of local councils in the Canton of Geneva, the Communauté des communes of the Pays de Gex, and the Ain Préfecture. This joint gift from the local authorities on both sides of the French-Swiss border has great symbolic value for an organisatio...

  19. Supplemental Oxygen for Paratroopers and Sky Divers

    Directory of Open Access Journals (Sweden)

    V. N. Jha

    2012-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Parajumping and sky diving in Armed Forces are used for rapid and strategic troop’s deployments. In the combat free fall (CFF, the troops are paradropped from high altitudes in excess of 30,000 ft above mean sea level (AMSL when they glide to a great distance, often within the enemy lines. Physiology of parajumping necessitates supplemental oxygen above 15,000 ft AMSL. Possibility of serious hypoxia and decompression sickness mandate the usage of supplemental oxygen through dedicated equipment. Other considerations such as effects of hypoxia on tissue oxygenation, physical and mental performance, neuronal functions, night vision, and prevailing anxiety factors, etc. also assume significance. Factors like intermittent hypoxic exposures, free fall, effects of posture during fall, and possible microgravity become mitigating factors. Owing to limited oxygen supply being carried by the paratroopers, using dilution method in providing the breathing gas too assumes importance at times as a trade-off between requirements and supply. This paper reviews the literatures to extent possible and recommends certain concepts for an optimal oxygen usage during the high altitude parajumps.Defence Science Journal, 2012, 62(1, pp.51-57, DOI:http://dx.doi.org/10.14429/dsj.62.599

  20. All-sky search of NAUTILUS data

    CERN Document Server

    Astone, P; Bonifazi, P; Borkowski, K M; Budzyński, R J; Chincarini, A; Coccia, E; D'Antonio, S; Emilio, M Di Paolo; Fafone, V; Frasca, S; Foffa, S; Giordano, G; Jaranowski, P; Kondracki, W; Królak, A; Maggiore, M; Marini, A; Minenkov, Y; Modena, I; Modestino, G; Moleti, A; Pallottino, G V; Palomba, C; Parodi, R; Pietka, M; Pizzella, G; Pletsch, H J; Quintieri, L; Ricci, F; Rocchi, A; Ronga, F; Sturani, R; Terenzi, R; Vaccarone, R; Visco, M

    2008-01-01

    A search for periodic gravitational-wave signals from isolated neutron stars in the NAUTILUS detector data is presented. We have analyzed half a year of data over the frequency band $$ Hz, the spindown range $$ Hz/s and over the entire sky. We have divided the data into 2 day stretches and we have analyzed each stretch coherently using matched filtering. We have imposed a low threshold for the optimal detection statistic to obtain a set of candidates that are further examined for coincidences among various data stretches. For some candidates we have also investigated the change of the signal-to-noise ratio when we increase the observation time from two to four days. Our analysis has not revealed any gravitational-wave signals. Therefore we have imposed upper limits on the dimensionless gravitational-wave amplitude over the parameter space that we have searched. Depending on frequency, our upper limit ranges from $3.4 \\times 10^{-23}$ to $1.3 \\times 10^{-22}$. We have attempted a statistical verification of th...

  1. ESA Sky: a new Astronomy Multi-Mission Interface

    OpenAIRE

    Merín, Bruno; Salgado, Jesús; Giordano, Fabrizio; Baines, Deborah; Sarmiento, María-Henar; Martí, Belén López; Racero, Elena; Gutiérrez, Raúl; Pollock, Andy; Rosa, Michael; Castellanos, Javier; González, Juan; De león, Ignacio; de Landaluce, Iñaki Ortiz; de Teodoro, Pilar

    2015-01-01

    We present a science-driven discovery portal for all the ESA Astronomy Missions called ESA Sky that allow users to explore the multi-wavelength sky and to seamlessly retrieve science-ready data in all ESA Astronomy mission archives from a web application without prior-knowledge of any of the missions. The first public beta of the service has been released, currently featuring an interface for exploration of the multi-wavelength sky and for single and/or multiple target searches of science-rea...

  2. Data indexing techniques for the EUVE all-sky survey

    Science.gov (United States)

    Lewis, J.; Saba, V.; Dobson, C.

    1992-01-01

    This poster describes techniques developed for manipulating large full-sky data sets for the Extreme Ultraviolet Explorer project. The authors have adapted the quatrilateralized cubic sphere indexing algorithm to allow us to efficiently store and process several types of large data sets, such as full-sky maps of photon counts, exposure time, and count rates. A variation of this scheme is used to index sparser data such as individual photon events and viewing times for selected areas of the sky, which are eventually used to create EUVE source catalogs.

  3. Wide-Field Sky Monitoring - Optical and X-rays

    Science.gov (United States)

    Hudec, R.; BART Teams; Ondrejov Observatory Lobster Eye Team

    We report on selected projects in wide-field sky imaging. This includes the recent efforts to digitize the astronomical sky plate archives and to apply these data for various scientific projects. We also address and discuss the status of the development of related algorithms and software programs. These data may easily provide very long term monitoring over very extended time intervals (up to more than 100 years) with limiting magnitudes between 12 and 23. The further experiments include CCD sky monitors, OMC camera onboard the ESA Integral satellite, robotic telescopes, and innovative wide-field X-ray telescopes.

  4. Treatment effect of balloon kyphoplasty and Sky expander kyphoplasty on vertebral compression fracture: a Meta-analysis

    Directory of Open Access Journals (Sweden)

    Wei HE

    2013-04-01

    Full Text Available Objective  To evaluate the treatment effect of balloon kyphoplasty (Pkp and Sky expander kyphoplasty (Sky on vertebral compression fracture, and provide a theoretical basis for clinical application. Methods  The database of Ovid medline, PubMed, Web of science, EMbase and CNKI from Jan. 1995 to Oct. 2012 were retrieved with computer, and relevant journals were manually retrieved, for the collection of the literature of therapeutic studies on treatment of vertebral compression fracture with Pkp and Sky method. The literature collected was then selected according to the inclusion and exclusion criteria, and analyzed by Meta-analysis software RevMan 5.0.25. Results  A total of 4 papers were selected based on that criterion, including 146 cases of Pkp group and 83 cases of Sky group. Random effect model analysis showed no significant difference existed between the two groups regarding postoperative anterior height and column height of vertebral body, Cobb angle and pain relieve (SMD=0.50, 95%CI -0.27–1.27; SMD=0.33, 95%CI -0.11–0.77; SMD=0.46, 95%CI -0.74–1.66; SMD=-0.09, 95%CI -0.37–0.18. However, the subgroup analysis showed the effect of Sky was better than that of Pkp on restoring anterior height and column height of vertebral body and Cobb angle. Conclusion  No significant difference was found regarding the treatment effect between Pkp and Sky method in the treatment of osteoporotic vertebral compression fracture, but the clinical effect of Sky was better because of fewer complications and lower medical cost.

  5. The Health Show

    OpenAIRE

    Swann, David

    2011-01-01

    Dr David Swann interviewed on The Health Show, Series 1, Episode 5, 2011 for BBC World about the award-winning 21st Century Nursing Bag. BBC World News reaches 241million people every week, available in 296 million homes, 1.8 million hotel rooms and has the highest average viewership on a weekday of any international news channel. The Health Show is a new 26-part series for BBC World News covering the most important news stories from around the world.

  6. Degradation of Sunset Yellow FCF using copper loaded bentonite and H2O2 as photo-Fenton like reagent

    Directory of Open Access Journals (Sweden)

    Kiran Chanderia

    2017-02-01

    Full Text Available In the present work, photo-Fenton degradation of Sunset Yellow FCF under visible light was carried out by using copper loaded bentonite and hydrogen peroxide. The photocatalyst was prepared by loading copper ions on bentonite by wet impregnation method. The rate of photocatalytic degradation of dye was measured spectrophotometrically by measuring absorbance of the reaction mixture at regular time intervals. The effect of various parameters such as pH, concentration of dye, amount of photocatalyst, amount of H2O2 and light intensity on the reaction rate has also been studied. Characterization of photocatalyst has been done by IR spectroscopy, scanning electron microscopy and X-ray diffraction. The Chemical Oxygen Demand (COD of the reaction mixture has been determined before and after treatment. A tentative mechanism involving ·≡OH radical as an oxidant for degradation of dye has also been proposed. Involvement of ·≡OH radicals as an active oxidizing agent has been confirmed by using isopropanol and butylated hydroxy toluene (BHT as radical scavengers. It has been observed that the rate of reaction is drastically reduced in the presence of these scavengers. The rate of reaction is much retarded by using BHT as compared with isopropanol.

  7. A humidity sensitive two-dimensional tunable amorphous photonic structure in the outer layer of bivalve ligament from Sunset Siliqua

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weigang, E-mail: abczwg15@163.com [College of Materials and Chemical Engineering, Chuzhou University, Chuzhou 239000 (China); Zhang, Gangsheng [College of Material Science and Technology, Guangxi University, Nanning 530004 (China)

    2015-07-01

    A humidity sensitive two-dimensional tunable amorphous photonic structure (2D TAPS) in the outer layer of bivalve ligament from Sunset Siliqua (OLLS) was reported in this paper. The structural color and microstructure of OLLS were investigated by reflection spectra and scanning electron microscopy, respectively. The results indicate that the reflection peak wavelength of the wet OLLS blue-shifts from 454 nm to 392 nm with the increasing of air drying time from 0 to 40 min, while the reflectivity decreases gradually and vanishes at last, relevant color changes from blue to black background color. The structural color in the OLLS is produced by a two-dimensional amorphous photonic structure consisting of aligned protein fibers, in which the diameter of protein fiber and the inter-fiber spacing are 101 ± 12 nm. Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure, and the regulation achieved through dynamically tuning the interaction between inter-fiber spacing and average refractive index. - Highlights: • A humidity sensitive two-dimensional tunable amorphous photonic structure • Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure. • This photonic structure may yield very useful template for artificial structures.

  8. A humidity sensitive two-dimensional tunable amorphous photonic structure in the outer layer of bivalve ligament from Sunset Siliqua.

    Science.gov (United States)

    Zhang, Weigang; Zhang, Gangsheng

    2015-01-01

    A humidity sensitive two-dimensional tunable amorphous photonic structure (2D TAPS) in the outer layer of bivalve ligament from Sunset Siliqua (OLLS) was reported in this paper. The structural color and microstructure of OLLS were investigated by reflection spectra and scanning electron microscopy, respectively. The results indicate that the reflection peak wavelength of the wet OLLS blue-shifts from 454 nm to 392 nm with the increasing of air drying time from 0 to 40 min, while the reflectivity decreases gradually and vanishes at last, relevant color changes from blue to black background color. The structural color in the OLLS is produced by a two-dimensional amorphous photonic structure consisting of aligned protein fibers, in which the diameter of protein fiber and the inter-fiber spacing are 101 ± 12 nm. Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure, and the regulation achieved through dynamically tuning the interaction between inter-fiber spacing and average refractive index.

  9. Sunset yellow FCF, a permitted food dye, alters functional responses of splenocytes at non-cytotoxic dose.

    Science.gov (United States)

    Yadav, Ashish; Kumar, Arvind; Tripathi, Anurag; Das, Mukul

    2013-03-13

    Sunset yellow FCF (SY), a permitted food color, is extensively used in various food preparations and quite often exceeds the permissible levels (100-200 mg/kg). Several toxicity studies on SY are reported, however immunomodulatory properties have not been explored yet. To investigate the immunotoxic properties of SY, splenocytes were isolated, cultured and subjected to mitogen stimulated proliferation assay (lipopolysaccharide, LPS or concanavalin A, Con A), mixed lymphocyte reaction (MLR) assay, immunophenotypic analysis of cell surface receptor expression and assay for cytokines release in the culture supernatants were performed in the presence of SY. Since SY did not exhibit any cytotoxicity up to 250 μg/ml, this dose was used for further studies. It was observed that SY (250 μg/ml) significantly (p<0.05) suppressed the mitogen induced proliferation of splenocytes and MLR response. Further, immunophenotypic analysis revealed that SY alters the relative expression of CD3e/CD4/CD8 in T cells and CD19 in B-cells. Consistent with the suppression of T-cell and B-cell responses and altered surface receptor expression, SY also lowered the expression of IL2, IL4, IL6, IL-17, IFN-γ and TNF-α cytokines. These results suggest that non-cytotoxic dose of SY may have immunomodulatory effects.

  10. Tartrazine and sunset yellow are xenoestrogens in a new screening assay to identify modulators of human oestrogen receptor transcriptional activity.

    Science.gov (United States)

    Axon, Andrew; May, Felicity E B; Gaughan, Luke E; Williams, Faith M; Blain, Peter G; Wright, Matthew C

    2012-08-16

    Primary biliary cirrhosis (PBC) is a cholestatic liver disease of unknown cause that occurs most frequently in post-menopausal women. Since the female sex hormone oestrogen can be cholestatic, we hypothesised that PBC may be triggered in part by chronic exposure to xenoestrogens (which may be more active on a background of low endogenous oestrogen levels seen in post-menopausal women). A reporter gene construct employing a synthetic oestrogen response element predicted to specifically interact with oestrogen receptors (ER) was constructed. Co-transfection of this reporter into an ER null cell line with a variety of nuclear receptor expression constructs indicated that the reporter gene was trans-activated by ERα and ERβ, but not by the androgen, thyroid, progesterone, glucocorticoid or vitamin D receptors. Chemicals linked to PBC were then screened for xenoestrogen activity in the human ERα-positive MCF-7 breast cancer cell line. Using this assay, the coal-derived food and cosmetic colourings--sunset yellow and tartrazine--were identified as novel human ERα activators, activating the human ER with an EC(50%) concentration of 220 and 160 nM, respectively.

  11. A Fashion Show

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>Story: The yearly fashion show day.The children take turns to walk on the stage and show the class their favorite clothes.Now it’s Joe’s and Phoebe’s turn.Joe walks on the stage and says,“My shorts are blue.Do you like my blue shorts?”On the other side of the stage, Phoebe is wearing her favorite pink skirt.“My skirt is pink.Do you like my pink skirt?”asks

  12. Using All Sky Imaging to Improve Telescope Scheduling

    Science.gov (United States)

    Cole, Gary M.

    2017-06-01

    Automated scheduling makes it possible for a small telescope to observe a large number of targets in a single night. But when used in areas which have less-than-perfect sky conditions such automation can lead to large numbers of observations of clouds and haze. This paper describes the development of a "sky-aware" telescope automation system that integrates the data flow from an SBIG AllSky340c camera with an enhanced dispatch scheduler to make optimum use of the available observing conditions for two highly instrumented backyard telescopes. Using the minute by minute time series image stream and a self maintained reference database, the software maintains a file of sky brightness, transparency, stability, and forecasted visibility at several hundred grid positions. The scheduling software uses this information in real time to exclude targets obscured by clouds and select the best observing task, taking into account the requirements and limits of each instrument.

  13. Sky color near the horizon during a total solar eclipse.

    Science.gov (United States)

    Gedzelman, S D

    1975-12-01

    A theory for the color of the sky near the horizon for an observer in the umbral region of a total solar eclipse is presented. The model uses a Rayleigh scattering atmosphere, and the light reaching the observer is a beam of singly scattered sunlight, which, in turn, has suffered depletion by scattering in its passage from outside the shadow region. The model predicts both the red color observed in the lowest 8 degrees of the sky for the total solar eclipse of 30 June 1973 and the enriched blue color of the sky at any elevation angle greater than the solar elevation angle. The model is also adapted to explain the reddening of the horizon sky observed during such times as when a dark cloud passes overhead or when the light from a large city is seen from the distance at night.

  14. Sky pixelization for the analysis of extended emission

    Science.gov (United States)

    Verkhodanov, O. V.; Doroshkevich, A. G.

    2013-08-01

    Spherical pixelization schemes are reviewed that allow analyzing extended emission and, in particular, the cosmic microwave background. Problems with implementing different schemes are considered. The nonhierarchical Gauss-Legendre sky pixelization (GLESP) approach is discussed in detail.

  15. The High Time Resolution Radio Sky

    Science.gov (United States)

    Thornton, D.

    2013-11-01

    Pulsars are laboratories for extreme physics unachievable on Earth. As individual sources and possible orbital companions can be used to study magnetospheric, emission, and superfluid physics, general relativistic effects, and stellar and binary evolution. As populations they exhibit a wide range of sub-types, with parameters varying by many orders of magnitude signifying fundamental differences in their evolutionary history and potential uses. There are currently around 2200 known pulsars in the Milky Way, the Magellanic clouds, and globular clusters, most of which have been discovered with radio survey observations. These observations, as well as being suitable for detecting the repeating signals from pulsars, are well suited for identifying other transient astronomical radio bursts that last just a few milliseconds that either singular in nature, or rarely repeating. Prior to the work of this thesis non-repeating radio transients at extragalactic distances had possibly been discovered, however with just one example status a real astronomical sources was in doubt. Finding more of these sources was a vital to proving they were real and to open up the universe for millisecond-duration radio astronomy. The High Time Resolution Universe survey uses the multibeam receiver on the 64-m Parkes radio telescope to search the whole visible sky for pulsars and transients. The temporal and spectral resolution of the receiver and the digital back-end enable the detection of relatively faint, and distant radio sources. From the Parkes telescope a large portion of the Galactic plane can be seen, a rich hunting ground for radio pulsars of all types, while previously poorly surveyed regions away from the Galactic plane are also covered. I have made a number of pulsar discoveries in the survey, including some rare systems. These include PSR J1226-6208, a possible double neutron star system in a remarkably circular orbit, PSR J1431-471 which is being eclipsed by its companion with

  16. On not showing scalps

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2016-01-01

    proposed by Janet Marstine, the editor of the Routledge Companion to Museum Ethics, I show how the museum succeeded in engaging users in questions of museum ethics. However, this specific debate on human remains in museums developed into an encounter between a global, museological discourse...

  17. Violence and TV Shows

    OpenAIRE

    ÖZTÜRK, Yrd. Doç. Dr. Şinasi

    2008-01-01

    This study aims to discuss theories on theviolent effects of TV shows on viewers, especiallyon children. Therefore, this study includes a briefdiscussion of definitions of violence, discussionof violence theories, main results of researcheson televised violence, measuring TV violence,perception of televised violence, individualdifferences and reactions to TV violence,aggressiveness and preferences for TV violence.

  18. Honored Teacher Shows Commitment.

    Science.gov (United States)

    Ratte, Kathy

    1987-01-01

    Part of the acceptance speech of the 1985 National Council for the Social Studies Teacher of the Year, this article describes the censorship experience of this honored social studies teacher. The incident involved the showing of a videotape version of the feature film entitled "The Seduction of Joe Tynan." (JDH)

  19. A Visionary Show

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Seduction. Distinction. Relax. Pulsation. These are the "style universes" on display at Première Vision, heralded as "The World’s Premiere Fabric Show." Started more than 35 years ago by 15 French weavers, Première Vision has expanded beyond its

  20. Honored Teacher Shows Commitment.

    Science.gov (United States)

    Ratte, Kathy

    1987-01-01

    Part of the acceptance speech of the 1985 National Council for the Social Studies Teacher of the Year, this article describes the censorship experience of this honored social studies teacher. The incident involved the showing of a videotape version of the feature film entitled "The Seduction of Joe Tynan." (JDH)

  1. Dark Skies, Bright Kids! Year 4

    Science.gov (United States)

    Sokal, Kimberly R.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R.; Borish, J.; Crawford, S. B.; Corby, J.; Damke, G.; Dean, J.; Dorsey, G.; Jackson, L.; Liss, S.; Oza, A.; Peacock, S.; Prager, B.; Romero, C.; Sivakoff, G. R.; Walker, L.; Whelan, D. G.; Zucker, C.

    2013-01-01

    Aiming to engage young children's natural excitement and curiosity, the outreach group Dark Skies, Bright Kids (DSBK) brings a hands-on approach to astronomy to elementary schools in Virginia. We hope to enhance children's view and understanding of science while exploring the Universe using fun activities. DSBK focuses on rural and underserved schools in Albemarle County and offers a semester-long astronomy club for third through fifth grade students. We believe regular interactions foster personal relationships between students and volunteers that encourage a life-long interest in science. In our fourth year of hosting clubs, we returned to Ivy Creek Elementary School, where we saw wonderful responses from a special group of students with `low-incidence' disabilities. DSBK has grown to realize a broader reach beyond local astronomy clubs; we hope to ignite a spark of interest in astronomy and science more widely- in more children, their families, and their teachers. We also hosted the Second Annual Central Virginia Star Party with an open invitation to the community to encourage families to enjoy astronomy together. Throughout the year, DSBK now holds 'one-off' programs (akin to astronomy field days) for elementary schools and children's groups throughout Virginia. Furthermore, we are in the final stages of a project to create two bilingual astronomy books called "Snapshots of the Universe", in Spanish and French with English translations. This art book will be made available online and we are working to get a copy in every elementary school in the state. DSBK has begun to reach out to elementary school teachers in order to provide them with useful and engaging classroom material. We have adapted our volunteer-created activities into useful and ready-to-use lessons, available online. After improvements based on research through interactions and feedback from teachers, we have explicitly identified the learning goals in terms of Virginia's Standards of Learning

  2. Dark Skies, Bright Kids! Year 3

    Science.gov (United States)

    Whelan, David G.; Johnson, K. E.; Barcos-Munoz, L. D.; Beaton, R. L.; Borish, J.; Corby, J. F.; Dorsey, G.; Gugliucci, N. E.; Prager, B. J.; Ries, P. A.; Romero, C. E.; Sokal, K. R.; Tang, X.; Walker, L. M.; Yang, A. J.; Zasowski, G.

    2012-01-01

    Dark Skies, Bright Kids! (DSBK) is a program that brings astronomy education to elementary schools throughout central Virginia. In a relaxed, out-of-classroom atmosphere, we are able to foster the innate curiosity that young students have about science and the world around them. We target schools that are under-served due to their rural locale or special needs students, demonstrating that science is a fun and creative process to a segment of the population that might not otherwise be exposed to astronomy. Families are included in the learning experience during semi-annual `star parties'. Since last January, we have expanded the breadth and depth of our educational capabilities. We have developed new programs for use in our digital planetarium. We held the first Central Virginia Star Party, providing an atmosphere where local children from multiple schools were able to share their love for astronomy. Local government and University officials were also invited so that they could experience our focused science outreach. Most recently, we have become part of Ivy Creek School's Club Day activities, bringing our program to a new segment of the elementary school system in Albemarle County: those that have `low-incidence' disabilities, requiring special attention. We continue to develop a curriculum for after-school programs that functions as either a series of one-time activities or several months of focused outreach at one school. Many of these activities are provided on our website, http://www.astro.virginia.edu/dsbk/, for the wider astronomical community, including the new planetarium work. We have extended our book project to include two bilingual astronomy books called `Snapshots of the Universe,' one in Spanish and English, the other in French and English. These books introduce young people to some of the many wonders of the Universe through art and captions developed by DSBK volunteers.

  3. "Sausage" and "Toothbrush" in the Sky

    Science.gov (United States)

    Jee, Myungkook J.; Dawson, William; Van Weeren, Reinout J.; Wittman, David M.; Merging Cluster Collaborations

    2016-06-01

    Radio-relic clusters are a subclass of merging clusters that exhibit elongated diffuse radio emissions at the periphery of the systems. A number of observational and theoretical studies support the premise that the relics trace the locations of shock fronts induced by cluster mergers. Detailed analysis of the radio relic data enables us to put independent constraints on the key parameters necessary in our reconstruction of the merging scenario, including the direction of the merger, the projection angle between the merger axis and the plane of the sky, the shock velocity, and the time since the impact. Because of the limited observational time window set by both development and deterioration of mature shocks, only a few tens of radio relic clusters are known to date. In this poster, we present a detailed study of the two radio-relic clusters CIZA J2242.8+5301 and RX J0603.3+4214, whose peculiar radio-relic morphologies give them the nicknames "Sausage" and "Toothbrush", respectively. Both clusters possess remarkably large (~2 Mpc) radio relics stretched perpendicular to the hypothesized merger axes. After briefly reviewing previous studies, we highlight our recent weak-lensing analysis of these two interesting systems. We find that the "Sausage" cluster's dark matter is elongated along the merger axis and composed of two massive systems, each weighing ~1015 solar masses. On the other hand, the dark matter of the "Toothbrush" cluster is distributed complicatedly and resolved into at least four subclusters with relatively modest masses. Our weak-lensing studies help us to constrain the merger scenarios and enable detailed follow-up numerical studies in the future.

  4. Full-sky Astrometric Mapping Explorer (FAME)

    Science.gov (United States)

    Johnston, K.; Gaume, R.; Harris, F.; Monet, D.; Murison, M.; Seidelmann, P. K.; Urban, S.; Johnson, M.; Horner, S.; Vassar, R.

    2000-12-01

    The FAME project began Phase B development in September 2000. FAME is a MIDEX class NASA Explorer mission that will perform an all-sky, astrometric survey with unprecedented accuracy. FAME will produce an astrometric catalog of 40 million stars between 5th and 15th magnitude. For the bright stars (5th to 9th magnitude) FAME will determine positions and parallaxes accurate to better than 50 microarcseconds, with proper motion errors less than 50 microarcseconds per year. For the fainter stars (between 9th and 15th magnitude) FAME will determine positions and parallaxes accurate to better than 500 microarcseconds, with proper motion errors less than 500 microarcseconds per year. FAME will also collect photometric data on these 40 million stars in four Sloan DSS colors. The FAME science, instrument, and spacecraft requirements and error budgets are being refined to establish the basis for the improved design of the instrument and spacecraft. The Attitude Control System (ACS) based on solar radiation pressure is being studied, including the limitations on the solar angle between the Sun and the rotation angle. The data processing plans are being developed. The CCD procurement contract is in place and design and fabrication of the CCDs is in progress. CCD tests for operations in various Time Delay Integration (TDI) situations are underway and described in another poster. It appears that the current FAME launch schedule will be delayed somewhat due to recent NASA budget restrictions. The FAME project is funded by the NASA Explorer program administered by Goddard Space Flight Center for the Office of Space Science under contract number S-13610-Y.

  5. 柠檬黄、日落黄在含乳饮料中褪色分析及改进%Analysis and improvement on fading of tartrazine and sunset yellow in milk beverage

    Institute of Scientific and Technical Information of China (English)

    余立意; 薛玉清; 杨忻怡; 舒成亮; 欧凯; 李言郡; 马海然

    2016-01-01

    目的:分析人工偶氮类色素柠檬黄、日落黄在含乳饮料中的褪色原因。方法通过测定Lab值,比色法计算其ΔE值,对比柠檬黄和日落黄与β-胡萝卜素在普通水体系以及含乳体系中的褪色速率,同时设计试验对比以乳清分离蛋白和酪朊酸钠作为蛋白质来源体系中复配柠檬黄日落黄色素的褪色速度,并使用 Ellman’s法测定两者体系中巯基的数量。通过测定不同浓度半胱氨酸体系中复配柠檬黄日落黄色素的褪色情况,验证巯基数量对合成偶氮类色素褪色的影响。结果在普通水体系中复配柠檬黄日落黄稳定性较好,褪色速度较慢,而在含乳体系中复配柠檬黄日落黄色素的褪色速度快于天然色素。Ellman’s法测定乳清分离蛋白的巯基数量远远大于酪朊酸钠,同时乳清蛋白体系中复配柠檬黄日落黄色素褪色速度快于酪朊酸钠体系。半胱氨酸浓度梯度实验显示,半胱氨酸浓度越高复配柠檬黄日落黄色素褪色越快。结论通过不同实验法案能够确定,含乳饮料中的巯基是导致合成偶氮类色素快速褪色的原因之一。%ABSTRACT:Objective To analyze the reasons for the color fading of tartrazine and sunset yellow in milk beverages. Methods The fading rates of mixed artificial color and β-carotene in water as well as milk beverage systems were compared using the colorimetry and the value ofΔE. In addition, the fading rates of mixed artificial color in the systems of whey protein isolate and sodium caseinate were also compared, and Ellman’s method was applied to determine the amount of sulfhydryl groups in those two kinds of systems. The effect of sulfhydryl groups on the fading of tartrazine and sunset yellow was verified by testing the fading rate at different concentration of cysteine systems. Results The results showed that the artificial color was more stable thanβ-carotene in a non-milksystem, but in

  6. 柠檬黄、日落黄在含乳饮料中褪色分析及改进%Analysis and improvement on fading of tartrazine and sunset yellow in milk beverage

    Institute of Scientific and Technical Information of China (English)

    余立意; 薛玉清; 杨忻怡; 舒成亮; 欧凯; 李言郡; 马海然

    2016-01-01

    目的:分析人工偶氮类色素柠檬黄、日落黄在含乳饮料中的褪色原因。方法通过测定Lab值,比色法计算其ΔE值,对比柠檬黄和日落黄与β-胡萝卜素在普通水体系以及含乳体系中的褪色速率,同时设计试验对比以乳清分离蛋白和酪朊酸钠作为蛋白质来源体系中复配柠檬黄日落黄色素的褪色速度,并使用 Ellman’s法测定两者体系中巯基的数量。通过测定不同浓度半胱氨酸体系中复配柠檬黄日落黄色素的褪色情况,验证巯基数量对合成偶氮类色素褪色的影响。结果在普通水体系中复配柠檬黄日落黄稳定性较好,褪色速度较慢,而在含乳体系中复配柠檬黄日落黄色素的褪色速度快于天然色素。Ellman’s法测定乳清分离蛋白的巯基数量远远大于酪朊酸钠,同时乳清蛋白体系中复配柠檬黄日落黄色素褪色速度快于酪朊酸钠体系。半胱氨酸浓度梯度实验显示,半胱氨酸浓度越高复配柠檬黄日落黄色素褪色越快。结论通过不同实验法案能够确定,含乳饮料中的巯基是导致合成偶氮类色素快速褪色的原因之一。%Objective To analyze the reasons for the color fading of tartrazine and sunset yellow in milk beverages. MethodsThe fading rates of mixed artificial color andβ-carotene in water as well as milk beverage systems were compared using the colorimetry and the value ofΔE. In addition, the fading rates of mixed artificial color in the systems of whey protein isolate and sodium caseinate were also compared, and Ellman’s method was applied to determine the amount of sulfhydryl groups in those two kinds of systems. The effect of sulfhydryl groups on the fading of tartrazine and sunset yellow was verified by testing the fading rate at different concentration of cysteine systems.ResultsThe results showed that the artificial color was more stable thanβ-carotene in a non-milksystem, but in milk beverage

  7. Sky Glow from Cities: The Army Illumination Model v2

    Science.gov (United States)

    2011-09-01

    corresponding to one 10th magnitude star per square degree and will not be pursued further here). Benn and Ellison find that the sky brightness at La Palma ...not have electricity, liquid and pressurized lamps are 23 included. For these latter two, liquid Citronella, lamp oil , liquid paraffin and...Properties; AFGL-TR-79-0214; Air Force Geophysics Laboratory: Hanscom Air Force Base, MA, 1979. 19. Benn, C. R. and Ellison, S. L. La Palma Night-Sky

  8. SKYMONITOR: A Global Network for Sky Brightness Measurements

    Science.gov (United States)

    Davis, Donald R.; Mckenna, D.; Pulvermacher, R.; Everett, M.

    2010-01-01

    We are implementing a global network to measure sky brightness at dark-sky critical sites with the goal of creating a multi-decade database. The heart of this project is the Night Sky Brightness Monitor (NSBM), an autonomous 2 channel photometer which measures night sky brightness in the visual wavelengths (Mckenna et al, AAS 2009). Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The NSBM consists of two parts, a remote unit and a base station with an internet connection. Currently these devices use 2.4 Ghz transceivers with a range of 100 meters. The remote unit is battery powered with daytime recharging using a solar panel. Data received by the base unit is transmitted via email protocol to IDA offices in Tucson where it will be collected, archived and made available to the user community via a web interface. Two other versions of the NSBM are under development: one for radio sensitive areas using an optical fiber link and the second that reads data directly to a laptop for sites without internet access. NSBM units are currently undergoing field testing at two observatories. With support from the National Science Foundation, we will construct and install a total of 10 units at astronomical observatories. With additional funding, we will locate additional units at other sites such as National Parks, dark-sky preserves and other sites where dark sky preservation is crucial. We will present the current comparison with the National Park Service sky monitoring camera. We anticipate that the SKYMONITOR network will be functioning by the end of 2010.

  9. Multiwavelength Astronomy Education with the Sloan Digital Sky Survey

    Science.gov (United States)

    Raddick, M. J.; Sparks, R.

    2004-05-01

    The Sloan Digital Sky Survey (SDSS) has developed an extensive array of education and public outreach activities, focused on the SkyServer web site. SkyServer (http://skyserver.sdss.org) offers easy access to the complete dataset of the SDSS, nearly 90 million stars and galaxies. Although the SDSS is primarily an optical survey, we have developed activities that link SDSS data to data from other surveys. Cross-correlations to ROSAT (x-rays) and FIRST (radio) are included in SkyServer, and many other surveys can be cross-correlated with SDSS data using SkyQuery (http://www.skyquery.org). We have developed a "Sky Surveys" activity for high school, community college, and college teachers. The activity teaches students about historical and modern sky surveys; students compare SDSS images to POSS (an optical survey from the 1950s), and compare images seen by the SDSS to the images of same objects from radio and x-ray data. The activity includes a teacher's guide with sample solutions, a lesson plan, and a scoring rubric. We are also developing other activities that use SkyQuery and the National Virtual Observatory's (http://www.us-vo.org) Data Inventory Service. In this presentation, I will demonstrate these activities, provide handouts for teachers, and discuss the future directions that SDSS outreach will take. We gratefully acknowledge funding from the Space Telescope Science Institute's IDEAS program (http://ideas.stsci.edu), the National Science Foundation's Small Grants for Exploratory Research (SGER) program, and the Maryland Space Grant Consortium.

  10. The Status of the NASA All Sky Fireball Network

    Science.gov (United States)

    Cooke, William J.; Moser, Danielle E.

    2011-01-01

    Established by the NASA Meteoroid Environment Office, the NASA All Sky Fireball Network consists of 6 meteor video cameras in the southern United States, with plans to expand to 15 cameras by 2013. As of mid-2011, the network had detected 1796 multi-station meteors, including meteors from 43 different meteor showers. The current status of the NASA All Sky Fireball Network is described, alongside preliminary results.

  11. Reconstructing the Sky Location of Gravitational-Wave Detected Compact Binary Systems: Methodology for Testing and Comparison

    Science.gov (United States)

    Sidney, T.; Aylott, B.; Christensen, N.; Farr, B.; Farr, W.; Feroz, F.; Gair, J.; Grover, K.; Graff, P.; Hanna, C.; Kalogera, V.; Mandel, I.; O'Shaughnessy, R.; Pitkin, M.; Price, L.; Raymond, V.; Roever, C.; Singer, L.; vanderSluys, M.; Smith, R. J. E.; Vecchio, A.; Veitch, J.; Vitale, S.

    2014-01-01

    The problem of reconstructing the sky position of compact binary coalescences detected via gravitational waves is a central one for future observations with the ground-based network of gravitational-wave laser interferometers, such as Advanced LIGO and Advanced Virgo. Different techniques for sky localization have been independently developed. They can be divided in two broad categories: fully coherent Bayesian techniques, which are high latency and aimed at in-depth studies of all the parameters of a source, including sky position, and "triangulation-based" techniques, which exploit the data products from the search stage of the analysis to provide an almost real-time approximation of the posterior probability density function of the sky location of a detection candidate. These techniques have previously been applied to data collected during the last science runs of gravitational-wave detectors operating in the so-called initial configuration. Here, we develop and analyze methods for assessing the self consistency of parameter estimation methods and carrying out fair comparisons between different algorithms, addressing issues of efficiency and optimality. These methods are general, and can be applied to parameter estimation problems other than sky localization. We apply these methods to two existing sky localization techniques representing the two above-mentioned categories, using a set of simulated inspiralonly signals from compact binary systems with a total mass of equal to or less than 20M solar mass and nonspinning components. We compare the relative advantages and costs of the two techniques and show that sky location uncertainties are on average a factor approx. equals 20 smaller for fully coherent techniques than for the specific variant of the triangulation-based technique used during the last science runs, at the expense of a factor approx. equals 1000 longer processing time.

  12. Seeing the sky through Hubble's eye: The COSMOS SkyWalker

    CERN Document Server

    Jahnke, K; Koekemoer, A

    2006-01-01

    Large, high-resolution space-based imaging surveys produce a volume of data that is difficult to present to the public in a comprehensible way. While megapixel-sized images can still be printed out or downloaded via the World Wide Web, this is no longer feasible for images with 10^9 pixels (e.g., the Hubble Space Telescope Advanced Camera for Surveys [ACS] images of the Galaxy Evolution from Morphology and SEDs [GEMS] project) or even 10^10 pixels (for the ACS Cosmic Evolution Survey [COSMOS]). We present a Web-based utility called the COSMOS SkyWalker that allows viewing of the huge ACS image data set, even through slow Internet connections. Using standard HTML and JavaScript, the application successively loads only those portions of the image at a time that are currently being viewed on the screen. The user can move within the image by using the mouse or interacting with an overview image. Using an astrometrically registered image for the COSMOS SkyWalker allows the display of calibrated world coordinates f...

  13. Shanghai Shows Its Heart

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The city known as China’s economic powerhouse showed a more caring face as host of the Special Olympic Games Between October 2 and 11,the Special Olympics Summer Games were hosted in Shanghai,the first time the 40-year-old athletic com- petition for people with intellectual disabilities came to a developing country. This Special Olympics was also larger than all previous games in temps of the number of athletes.

  14. Night Sky Brightness at San Pedro Martir Observatory

    Science.gov (United States)

    Plauchu-Frayn, I.; Richer, M. G.; Colorado, E.; Herrera, J.; Córdova, A.; Ceseña, U.; Ávila, F.

    2017-03-01

    We present optical UBVRI zenith night sky brightness measurements collected on 18 nights during 2013 to 2016 and SQM measurements obtained daily over 20 months during 2014 to 2016 at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir (OAN-SPM) in México. The UBVRI data is based upon CCD images obtained with the 0.84 m and 2.12 m telescopes, while the SQM data is obtained with a high-sensitivity, low-cost photometer. The typical moonless night sky brightness at zenith averaged over the whole period is U = 22.68, B = 23.10, V = 21.84, R = 21.04, I = 19.36, and SQM = 21.88 {mag} {{arcsec}}-2, once corrected for zodiacal light. We find no seasonal variation of the night sky brightness measured with the SQM. The typical night sky brightness values found at OAN-SPM are similar to those reported for other astronomical dark sites at a similar phase of the solar cycle. We find a trend of decreasing night sky brightness with decreasing solar activity during period of the observations. This trend implies that the sky has become darker by Δ U = 0.7, Δ B = 0.5, Δ V = 0.3, Δ R=0.5 mag arcsec‑2 since early 2014 due to the present solar cycle.

  15. Open Skies: Facilitating the many dimensions of transparency

    Energy Technology Data Exchange (ETDEWEB)

    Allentuck, J.

    1993-08-01

    The Treaty on Open Skies (Open Skies) was signed on 24 March 1992 by 23 European nations in addition to the United States and Canada. Unlike other arms control treaties which prohibit specific weapons or weapon systems, Open Skies is intended to provide, in the words of its preamble, means ``to facilitate the monitoring of compliance with existing or future arms control agreements.`` In addition, its objectives include the ``improvement of openness and transparency for conflict prevention and crises management in the framework of the Conference on Security and Cooperation in Europe and in other relevant international institutions.`` The preamble also alludes to the possible extension of the Open Skies regime into additional (non-arms control) fields, such as environmental protection. Not mentioned is an objective which the treaty would appear to strive to attain: to equalize to some degree the ability of nations to obtain intelligence deemed essential to their national security. This is in fact the case since it provides such means to signatories which otherwise do not have direct access to advanced information gathering technology. ``Open Skies`` also contributes to monitoring or treaty verification by providing an instrument for cuing further investigation of information which might indicate impending treaty violation. Thus, while appearing unfocussed from a monitoring or treaty verification point of view, Open Skies represents substantial progress toward facilitating transparency.

  16. South African night sky brightness during high aerosol epochs

    CERN Document Server

    Winkler, Hartmut; Marang, Fred

    2014-01-01

    Sky conditions in the remote, dry north-western interior of South Africa are now the subject of considerable interest in view of the imminent construction of numerous solar power plants in this area. Furthermore, the part of this region in which the core of the SKA is to be located (which includes SALT) has been declared an Astronomical Advantage Zone, for which sky brightness monitoring will now be mandatory. In this project we seek to characterise the sky brightness profile under a variety of atmospheric conditions. Key factors are of course the lunar phase and altitude, but in addition the sky brightness is also significantly affected by the atmospheric aerosol loading, as that influences light beam scattering. In this paper we chose to investigate the sky characteristics soon after the Mount Pinatubo volcanic eruption in 1991, which resulted in huge ash masses reaching the stratosphere (where they affected solar irradiance for several years). We re-reduced photometric sky measurements from the South Afric...

  17. New Sky Flats for HST's ACS/WFC

    Science.gov (United States)

    Lucas, Ray A.; Grogin, Norman A.

    2016-06-01

    We have begun experiments to make new sky flat files for HST's ACS/WFC. Sky flats can be especially useful for deep imaging in such as programs as deep, extragalactic survey programs because they can help to better deal with noise at low levels. Although we also hope to make similar sky flats for some other popular filters including F606W and F814W, we are beginning this experiment with the F435W filter on the ACS/WFC since it is a popular filter in use in many deep extragalactic surveys, and since the bluer filters such as F435W generally have lower throughput and images in that filter are typically noisier than others at some longer mid-optical wavelengths. Initially, although sources will be masked in these images, etc. we are endeavoring to use just post-SM4 F435W images of duration equal to or greater than 800 seconds and which are free of bright stars in order to try and avoid scattered light and sky background color issues as much as possible, although the sky in different images taken at different times and in different directions will likely have some different background levels and color terms in any event. However, our hope is that the final sky flats will be of sufficient S/N to be good calibrators for deep survey programs.

  18. The sky pattern of the linearized gravitational memory effect

    Science.gov (United States)

    Mädler, Thomas; Winicour, Jeffrey

    2016-09-01

    The gravitational memory effect leads to a net displacement in the relative positions of test particles. This memory is related to the change in the strain of the gravitational radiation field between infinite past and infinite future retarded times. There are three known sources of the memory effect: (i) the loss of energy to future null infinity by massless fields or particles, (ii) the ejection of massive particles to infinity from a bound system and (iii) homogeneous, source-free gravitational waves. In the context of linearized theory, we show that asymptotic conditions controlling these known sources of the gravitational memory effect rule out any other possible sources with physically reasonable stress-energy tensors. Except for the source-free gravitational waves, the two other known sources produce gravitational memory with E-mode radiation strain, characterized by a certain curl-free sky pattern of their polarization. Thus our results show that the only known source of B-mode gravitational memory is of primordial origin, corresponding in the linearized theory to a homogeneous wave entering from past null infinity.

  19. The sky pattern of the linearized gravitational memory effect

    CERN Document Server

    Mädler, Thomas

    2016-01-01

    The gravitational memory effect leads to a net displacement in the relative positions of test particles. This memory is related to the change in the strain of the gravitational radiation field between infinite past and infinite future retarded times. There are three known sources of the memory effect: (i) the loss of energy to future null infinity by massless fields or particles, (ii) the ejection of massive particles to infinity from a bound system and (iii) homogeneous, source-free gravitational waves. In the context of linearized theory, we show that asymptotic conditions controlling these known sources of the gravitational memory effect rule out any other possible sources with physically reasonable stress-energy tensors. Except for the source-free gravitational waves, the two other known sources produce gravitational memory with E-mode radiation strain, characterized by a certain curl-free sky pattern of their polarization. Thus our results show that the only known source of B-mode gravitational memory is...

  20. 马自达新一代动力传动系统SKY%New Driveline SKY from Mazda

    Institute of Scientific and Technical Information of China (English)

    忻文

    2010-01-01

    @@ 马自达日前发布了计划在2011年上市的新款车中配备的新一代动力传动系统.这一名为"SKY"的动力系统系列由2.0L排量直4汽油发动机"SKY-G"、2.2L直4柴油发动机"SKY-D"、6档自动变速器(AT)"SKY-Drive"及新型6档手动变速器(MT)构成,实现了小型轻量化与高效化.

  1. The Sky Polarization Observatory (SPOrt): a project to measure the diffused sky polarization from the International Space Station Alpha (ISSA)

    Science.gov (United States)

    Cortiglioni, S.

    1999-07-01

    The Sky Polarization Observatory (SPOrt), a project to measure the diffused sky polarization in the frequency range of 22-90 GHz from the International Space Station, is described in its current configuration. Some preliminary considerations about the general topic of polarization in radiometric observations are made, in order to introduce the importance of polarimetric measurements in the more general context of Cosmic Microwave Background observations. The International Space Station is also introduced as a quite good opportunity to address such problematics.

  2. Not a "reality" show.

    Science.gov (United States)

    Wrong, Terence; Baumgart, Erica

    2013-01-01

    The authors of the preceding articles raise legitimate questions about patient and staff rights and the unintended consequences of allowing ABC News to film inside teaching hospitals. We explain why we regard their fears as baseless and not supported by what we heard from individuals portrayed in the filming, our decade-long experience making medical documentaries, and the full un-aired context of the scenes shown in the broadcast. The authors don't and can't know what conversations we had, what documents we reviewed, and what protections we put in place in each televised scene. Finally, we hope to correct several misleading examples cited by the authors as well as their offhand mischaracterization of our program as a "reality" show.

  3. Evidence of Clear-Sky Daylight Whitening: Are we already conducting geoengineering?

    Science.gov (United States)

    Long, C. N.; Flynn, C. J.; Barnard, J.

    2015-12-01

    Long et al. (2009, JGR 114) analyzed surface radiation data spanning 1995 through 2007 from several ARM and six SURFRAD sites across the continental US, and showed an average 8 Wm-2/decade brightening in all-sky downwelling SW. The study also showed a 5 Wm-2/decade increase in the clear-sky downwelling SW, an expected result of decreasing aerosol optical depths during the same time period (Augustine et al., 2008, JGR 113). However, the unexpected result of the Long et al. study is that the 5 Wm-2/decade increase occurred in the diffuse SW, while the direct SW remained virtually unchanged...opposite what is expected for aerosol direct effect due to decreases in aerosols. With detailed radiative transfer modeling and correlation with US FAA commercial flight hours through the same years, Long et al. suggested that while the decreased aerosols did increase the total SW, an increase in high, sub-visual contrail-generated ice haze repartitioned the increase into the diffuse SW component through large-mode particle scattering. Subsequent attempts to investigate the veracity of this speculation using long time series of ARM Micropulse and Raman lidars data proved untenable due to instrument limitations and continuity issues. However, similar to using the red/blue ratio of pixel color amounts in processing color sky images to infer clouds, we have used clear-sky diffuse SW irradiance measurements from the Multi-Frequency Rotating Shadowband Radiometer (MFRSR) 870, 500, and 415 nm spectral channels to look at any possible trends suggesting "whitening" of the cloud-free skies over the ARM SGP site. We will present our preliminary findings to date of these investigations suggesting indeed that there has been an aggregate "whitening" of the sky conditions we typically consider to be "cloud free." Augustine, J.A., G.B.Hodges, E.G.Dutton, J.J. Michalsky, and C.R.Cornwall (2008), An aerosol optical depth climatology for NOAA's national surface radiation budget network (SURFRAD

  4. Spectral and Spatial UV Sky Radiance Measurements at a Seaside Resort Under Clear Sky and Slightly Overcast Conditions.

    Science.gov (United States)

    Sandmann, Henner; Stick, Carsten

    2014-01-01

    Spatial measurements of the diffusely scattered sky radiance at a seaside resort under clear sky and slightly overcast conditions have been used to calculate the sky radiance distribution across the upper hemisphere. The measurements were done in the summer season when solar UV radiation is highest. The selected wavelengths were 307, 350 and 550 nm representing the UVB, UVA and VIS band. Absolute values of radiance differ considerably between the wavelengths. Normalizing the measured values by use of direct solar radiance made the spatial distributions of unequal sky radiance comparable. The results convey a spatial impression of the different distributions of the radiance at the three wavelengths. Relative scattered radiance intensity is one order of magnitude greater in UVB than in VIS, whereas in UVA lies roughly in between. Under slightly overcast conditions scattered radiance is increased at all three wavelengths by about one order of magnitude. These measurements taken at the seaside underline the importance of diffuse scattered radiance. The effect of shading parts of the sky can be estimated from the distribution of sky radiance. This knowledge might be useful for sun seekers and in the treatment of people staying at the seaside for therapeutic purposes.

  5. Interpreting Sky-Averaged 21-cm Measurements

    Science.gov (United States)

    Mirocha, Jordan

    2015-01-01

    Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation

  6. Splitting Neutrino masses and Showering into Sky

    Science.gov (United States)

    Fargion, D.; D'Armiento, D.; Lanciano, O.; Oliva, P.; Iacobelli, M.; de Sanctis Lucentini, P. G.; Grossi, M.; de Santis, M.

    2007-06-01

    Neutrino masses might be as light as a few time the atmospheric neutrino mass splitting. The relic cosmic neutrinos may cluster in wide Dark Hot Local Group Halo. High Energy ZeV cosmic neutrinos (in Z-Showering model) might hit relic ones at each mass in different resonance energies in our nearby Universe. This non-degenerated density and energy must split UHE Z-boson secondaries (in Z-Burst model) leading to multi injection of UHECR nucleons within future extreme AUGER energy. Secondaries of Z-Burst as neutral gamma, below a few tens EeV are better surviving local GZK cut-off and they might explain recent Hires BL-Lac UHECR correlations at small angles. A different high energy resonance must lead to Glashow's anti-neutrino showers while hitting electrons in matter. In water and ice it leads to isotropic light explosions. In air, Glashow's anti-neutrino showers lead to collimated and directional air-showers offering a new Neutrino Astronomy. Because of neutrino flavor mixing, astrophysical energetic tau neutrino above tens GeV must arise over atmospheric background. At TeV range is difficult to disentangle tau neutrinos from other atmospheric flavors. At greater energy around PeV, Tau escaping mountains and Earth and decaying in flight are effectively showering in air sky. These Horizontal showering is splitting by geomagnetic field in forked shapes. Such air-showers secondaries release amplified and beamed gamma bursts (like observed TGF), made also by muon and electron pair bundles, with their accompanying rich Cherenkov flashes. Also planet's largest (Saturn, Jupiter) atmosphere limbs offer an ideal screen for UHE GZK and Z-burst tau neutrino, because their largest sizes. Titan thick atmosphere and small radius are optimal for discovering up-going resonant Glashow resonant anti-neutrino electron showers. Detection from Earth of Tau, anti-Tau, anti-electron neutrino induced Air-showers by twin Magic Telescopes on top mountains, or space based detection on

  7. From Sky to Archive: Long Term Management of Sky Survey Data

    Science.gov (United States)

    Darch, Peter T.; Sands, Ashley E.; Borgman, Christine; Golshan, Milena S.; Traweek, Sharon

    2017-01-01

    Sky survey data may remain scientifically valuable long beyond the end of a survey’s operational period, both for continuing inquiry and for calibrating and testing instruments for subsequent generations of surveys. Astronomy infrastructure has many stakeholders, including those concerned with data management. Research libraries are increasingly partnering with scholars to sustain access to data.The Sloan Digital Sky Survey (SDSS) was among the first major scientific projects to partner with libraries in this way, embarking on a data transfer process with two university libraries. We report on a qualitative case study of this process.Ideally, long-term sustainability of sky survey data would be a key part of planning and construction, but rarely does this occur. Teams are under pressure to deliver a project on time and on budget that produces high-quality data during its operational period, leaving few resources available to plan long-term data management. The difficulty of planning is further compounded by the complexity of predicting circumstances and needs of the astronomy community in future decades. SDSS team members regarded libraries, long-lived institutions concerned with access to scholarship, as a potential solution to long-term data sustainability.As the SDSS data transfer was the first of this scale attempted - 160 TB of data - astronomers and library staff were faced with scoping the range of activities involved. They spent two years planning this five-year process. While successful overall as demonstration projects, the libraries encountered many obstacles. We found all parties experienced difficulty in articulating their notions of “scientific data,” “archiving,” “serving,” and “providing access” to the datasets. Activities and interpretations of the data transfer process varied by institutional motivations for participation and by available infrastructure. We conclude several, rather than a single, “library solutions” for long

  8. The Ultraviolet Sky: final catalogs of unique UV sources from GALEX, and characterization of the UV-emitting sources across the sky, and of the Milky Way extinction

    Science.gov (United States)

    Bianchi, Luciana; Conti, A.; Shiao, B.; Keller, G. R.; Thilker, D. A.

    2014-01-01

    The legacy of the Galaxy Evolution Explorer (GALEX), which imaged the sky at Ultraviolet (UV) wavelengths for about 9 years, is its unprecedented database with more than 200 million source measurements in far-UV (FUV) and near-UV (NUV), as well as wide-field imaging of extended objects. GALEX's data, the first substantial sky surveys at UV wavelengths, offer an unprecedented view of the sky and a unique opportunity for an unbiased characterization of several classes of astrophysical objects, such as hot stars, QSOs at red-shift about 1, UV-peculiar QSOs, star-forming galaxies, among others. Bianchi et al. (2013, J. Adv. Space Res. (2013), DOI: http://dx.doi.org/10.1016/j.asr.2013.07.045) have constructed final catalogs of UV sources, with homogeneous quality, eliminating duplicate measurements of the same source ('unique' source catalogs), and excluding rim artifacts and bad photometry. The catalogs are constructed improving on the recipe of Bianchi et al. 2011 (MNRAS, 411, 2770, which presented the earlier version of these catalogs) and include all data for the major surveys, AIS and MIS. Considering the fields where both FUV and NUV detectors were exposed, the catalogs contain about 71 and 16.6 million unique sources respectively. We show several maps illustrating the content of UV sources across the sky, globally, and separately for bright/faint, hot, stellar/extragalactic objects. We matched the UV-source catalogs with optical-IR data from the SDSS, GSC2, 2MASS surveys. We are also in the process of matching the catalogs with preliminary PanSTARRS1 (PS1) 3pi survey photometry which already provides twice the sky coverage of SDSS, at slightly fainter magnitude limits. The sources' SED from FUV to optical wavelengths enables classification, derivation of the object physical parameters, and ultimately also a map of the Milky Way extinction. The catalogs will be available on MAST, Vizier (where the previous version already is), and in reduced form (for agile

  9. Showing Value (Editorial

    Directory of Open Access Journals (Sweden)

    Denise Koufogiannakis

    2009-06-01

    Full Text Available When Su Cleyle and I first decided to start Evidence Based Library and Information Practice, one of the things we agreed upon immediately was that the journal be open access. We knew that a major obstacle to librarians using the research literature was that they did not have access to the research literature. Although Su and I are both academic librarians who can access a wide variety of library and information literature from our institutions, we belong to a profession where not everyone has equal access to the research in our field. Without such access to our own body of literature, how can we ever hope for practitioners to use research evidence in their decision making? It would have been contradictory to the principles of evidence based library and information practice to do otherwise.One of the specific groups we thought could use such an open access venue for discovering research literature was school librarians. School librarians are often isolated and lacking access to the research literature that may help them prove to stakeholders the importance of their libraries and their role within schools. Certainly, school libraries have been in decline and the use of evidence to show value is needed. As Ken Haycock noted in his 2003 report, The Crisis in Canada’s School Libraries: The Case for Reform and Reinvestment, “Across the country, teacher-librarians are losing their jobs or being reassigned. Collections are becoming depleted owing to budget cuts. Some principals believe that in the age of the Internet and the classroom workstation, the school library is an artifact” (9. Within this context, school librarians are looking to our research literature for evidence of the impact that school library programs have on learning outcomes and student success. They are integrating that evidence into their practice, and reflecting upon what can be improved locally. They are focusing on students and showing the impact of school libraries and

  10. Evaluation of Clear Sky Models for Satellite-Based Irradiance Estimates

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, M.; Gotseff, P.

    2013-12-01

    This report describes an intercomparison of three popular broadband clear sky solar irradiance model results with measured data, as well as satellite-based model clear sky results compared to measured clear sky data. The authors conclude that one of the popular clear sky models (the Bird clear sky model developed by Richard Bird and Roland Hulstrom) could serve as a more accurate replacement for current satellite-model clear sky estimations. Additionally, the analysis of the model results with respect to model input parameters indicates that rather than climatological, annual, or monthly mean input data, higher-time-resolution input parameters improve the general clear sky model performance.

  11. 1,001 Celestial Wonders to See Before You Die The Best Sky Objects for Star Gazers

    CERN Document Server

    Bakich, Michael E

    2010-01-01

    Many deep-sky objects that can appear quite wonderful in photographs can be hard to observe in the telescope. This book is your guide to the more interesting nebulae, star clusters, and galaxies, objects that will bring gasps when you see them through a telescope. Author Michael E. Bakich shows you how to spot constellations you’ve heard of but haven’t been able to find. He gives you lists of bright deep-sky objects to target on clear nights. And he guides your search for the famous named splendors you’ve heard of — and perhaps seen a picture of — and would like to see through your own telescope. Bakich, an observer since he was in third grade, knows the sky better than most. In his current position as senior editor and also photo editor for the highly regarded Astronomy magazine, he has the technical expertise and finely honed communication skills to help you easily locate the best sites in the sky. His more than 250 astroimages help you identify the detail in these sky wonders. Bakich organizes hi...

  12. Exploring Milkyway Halo Substructures with Large-Area Sky Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ting [Texas A & M Univ., College Station, TX (United States)

    2016-01-01

    Over the last two decades, our understanding of the Milky Way has been improved thanks to large data sets arising from large-area digital sky surveys. The stellar halo is now known to be inhabited by a variety of spatial and kinematic stellar substructures, including stellar streams and stellar clouds, all of which are predicted by hierarchical Lambda Cold Dark Matter models of galaxy formation. In this dissertation, we first present the analysis of spectroscopic observations of individual stars from the two candidate structures discovered using an M-giant catalog from the Two Micron All-Sky Survey. The follow-up observations show that one of the candidates is a genuine structure which might be associated with the Galactic Anticenter Stellar Structure, while the other one is a false detection due to the systematic photometric errors in the survey or dust extinction in low Galactic latitudes. We then presented the discovery of an excess of main sequence turn-off stars in the direction of the constellations of Eridanus and Phoenix from the first-year data of the Dark Energy Survey (DES) – a five-year, 5,000 deg2 optical imaging survey in the Southern Hemisphere. The Eridanus-Phoenix (EriPhe) overdensity is centered around l ~ 285° and b ~ -60° and the Poisson significance of the detection is at least 9σ. The EriPhe overdensity has a cloud-like morphology and the extent is at least ~ 4 kpc by ~ 3 kpc in projection, with a heliocentric distance of about d ~ 16 kpc. The EriPhe overdensity is morphologically similar to the previously-discovered Virgo overdensity and Hercules-Aquila cloud. These three overdensities lie along a polar plane separated by ~ 120° and may share a common origin. In addition to the scientific discoveries, we also present the work to improve the photometric calibration in DES using auxiliary calibration systems, since the photometric errors can cause false detection in first the halo substructure. We present a detailed description of the two

  13. Public medical shows.

    Science.gov (United States)

    Walusinski, Olivier

    2014-01-01

    In the second half of the 19th century, Jean-Martin Charcot (1825-1893) became famous for the quality of his teaching and his innovative neurological discoveries, bringing many French and foreign students to Paris. A hunger for recognition, together with progressive and anticlerical ideals, led Charcot to invite writers, journalists, and politicians to his lessons, during which he presented the results of his work on hysteria. These events became public performances, for which physicians and patients were transformed into actors. Major newspapers ran accounts of these consultations, more like theatrical shows in some respects. The resultant enthusiasm prompted other physicians in Paris and throughout France to try and imitate them. We will compare the form and substance of Charcot's lessons with those given by Jules-Bernard Luys (1828-1897), Victor Dumontpallier (1826-1899), Ambroise-Auguste Liébault (1823-1904), Hippolyte Bernheim (1840-1919), Joseph Grasset (1849-1918), and Albert Pitres (1848-1928). We will also note their impact on contemporary cinema and theatre.

  14. Comparing PyMorph and SDSS photometry. I. Background sky and model fitting effects

    Science.gov (United States)

    Fischer, J.-L.; Bernardi, M.; Meert, A.

    2017-01-01

    A number of recent estimates of the total luminosities of galaxies in the SDSS are significantly larger than those reported by the SDSS pipeline. This is because of a combination of three effects: one is simply a matter of defining the scale out to which one integrates the fit when defining the total luminosity, and amounts on average to ≤0.1 mags even for the most luminous galaxies. The other two are less trivial and tend to be larger; they are due to differences in how the background sky is estimated and what model is fit to the surface brightness profile. We show that PyMorph sky estimates are fainter than those of the SDSS DR7 or DR9 pipelines, but are in excellent agreement with the estimates of Blanton et al. (2011). Using the SDSS sky biases luminosities by more than a few tenths of a magnitude for objects with half-light radii ≥7 arcseconds. In the SDSS main galaxy sample these are typically luminous galaxies, so they are not necessarily nearby. This bias becomes worse when allowing the model more freedom to fit the surface brightness profile. When PyMorph sky values are used, then two component Sersic-Exponential fits to E+S0s return more light than single component deVaucouleurs fits (up to ˜0.2 mag), but less light than single Sersic fits (0.1 mag). Finally, we show that PyMorph fits of Meert et al. (2015) to DR7 data remain valid for DR9 images. Our findings show that, especially at large luminosities, these PyMorph estimates should be preferred to the SDSS pipeline values.

  15. New liquid chromatographic-chemometric approach for the determination of sunset yellow and tartrazine in commercial preparation.

    Science.gov (United States)

    Dinç, Erdal; Aktaş, A Hakan; Ustündağ, Ozgür

    2005-01-01

    A new liquid chromatographic (LC)-chemometric approach was developed for the determination of sunset yellow (SUN) and tartrazine (TAR) in commercial preparations. This approach uses LC and chemometric calibration methods, i.e., classical least-squares (CLS), principal component regression (PCR), and partial-least squares (PLS), simultaneously. The combined LC-chemometric approaches, denoted as LC-CLS, LC-PCR, and LC-PLS, are based on photodiode array (PDA) detection at multiple wavelengths. Optimum chromatographic separation of SUN and TAR with allura red as the internal standard (IS) was obtained by using a Waters Symmetry C18 column, 5 microm, 4.6 x 250 mm, and 0.2 M acetate buffer (pH 5)-acetonitrile-methano-bidistilled water (55 + 20 + 15 + 10, v/v) as the mobile phase at a flow rate of 1.9 mL/min. The LC data sets consisting of the ratios of analyte peak areas to the IS peak area were obtained by using PDA detection at 5 wavelengths (465, 470, 475, 480, and 485 nm). LC-chemometric calibrations for SUN and TAR were separately constructed by using the relationship between the peak-area ratio and the training sets for each colorant. LC-chemometric approaches were tested for different synthetic mixtures containing SUN and TAR in the presence of the IS. These LC-chemometric calibrations were applied to a commercial preparation of the 2 colorants. The experimental results of the LC-chemometric approaches were compared with those obtained by a developed classical LC method using single-wavelength detection.

  16. Dark Skies Awareness Cornerstone Project for the International Year of Astronomy

    Science.gov (United States)

    Walker, C. E.; Pompea, S. M.; Iya Dark Skies Awareness Working Group

    2010-12-01

    Astronomy Month, in which the International Dark Sky Week will be celebrated. DSA will be collaborating with Belgium’s “Night of Darkness” to endeavor to make that lights out event a more global event. DSA will endeavor to support dark skies education worldwide, as in Northern Ireland. DSA will seek to expand light pollution prevention campaigns like Austria’s. People whose homes meet the criteria of good lighting are invited to put a sticker from Austria’s biggest newspaper in their front window to show their support. DSA also seeks to collaborate with the IAU Office for Astronomy Development. The presentation will focus on the DSA programs during IYA and the sustainability of the DSA programs after IYA, as well as the expansion to other programs worldwide, with particular emphasis in communicating dark skies awareness with the public and its educational value in attracting young people to study science and technology. See www.darkskiesawareness.org for more information on the programs.

  17. The Great Cometary Show

    Science.gov (United States)

    2007-01-01

    its high spatial and spectral resolution, it was possible to zoom into the very heart of this very massive star. In this innermost region, the observations are dominated by the extremely dense stellar wind that totally obscures the underlying central star. The AMBER observations show that this dense stellar wind is not spherically symmetric, but exhibits a clearly elongated structure. Overall, the AMBER observations confirm that the extremely high mass loss of Eta Carinae's massive central star is non-spherical and much stronger along the poles than in the equatorial plane. This is in agreement with theoretical models that predict such an enhanced polar mass-loss in the case of rapidly rotating stars. ESO PR Photo 06c/07 ESO PR Photo 06c/07 RS Ophiuchi in Outburst Several papers from this special feature focus on the later stages in a star's life. One looks at the binary system Gamma 2 Velorum, which contains the closest example of a star known as a Wolf-Rayet. A single AMBER observation allowed the astronomers to separate the spectra of the two components, offering new insights in the modeling of Wolf-Rayet stars, but made it also possible to measure the separation between the two stars. This led to a new determination of the distance of the system, showing that previous estimates were incorrect. The observations also revealed information on the region where the winds from the two stars collide. The famous binary system RS Ophiuchi, an example of a recurrent nova, was observed just 5 days after it was discovered to be in outburst on 12 February 2006, an event that has been expected for 21 years. AMBER was able to detect the extension of the expanding nova emission. These observations show a complex geometry and kinematics, far from the simple interpretation of a spherical fireball in extension. AMBER has detected a high velocity jet probably perpendicular to the orbital plane of the binary system, and allowed a precise and careful study of the wind and the shockwave

  18. NOAA AVHRR Clear-Sky Products over Oceans (ACSPO): Sea Surface Temperature, Clear Sky Radiances, and Aerosol Optical Depth for the Global Ocean, 2011 - present (NCEI Accession 0072979)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The AVHRR Clear-Sky Processor over Oceans, jointly developed between NESDIS STAR and OSDPD, produces AVHRR clear-sky products over oceans. ACSPO generates output...

  19. Reconstruction of MODIS Spectral Reflectance under Cloudy-Sky Condition

    Directory of Open Access Journals (Sweden)

    Bo Gao

    2016-09-01

    Full Text Available Clouds usually cause invalid observations for sensors aboard satellites, which corrupts the spatio-temporal continuity of land surface parameters retrieved from remote sensing data (e.g., MODerate Resolution Imaging Spectroradiometer (MODIS data and prevents the fusing of multi-source remote sensing data in the field of quantitative remote sensing. Based on the requirements of spatio-temporal continuity and the necessity of methods to restore bad pixels, primarily resulting from image processing, this study developed a novel method to derive the spectral reflectance for MODIS band of cloudy pixels in the visual–near infrared (VIS–NIR spectral channel based on the Bidirectional Reflectance Distribution Function (BRDF and multi-spatio-temporal observations. The proposed method first constructs the spatial distribution of land surface reflectance based on the corresponding BRDF and the solar-viewing geometry; then, a geographically weighted regression (GWR is introduced to individually derive the spectral surface reflectance for MODIS band of cloudy pixels. A validation of the proposed method shows that a total root-mean-square error (RMSE of less than 6% and a total R2 of more than 90% are detected, which indicates considerably better precision than those exhibited by other existing methods. Further validation of the retrieved white-sky albedo based on the spectral reflectance for MODIS band of cloudy pixels confirms an RMSE of 3.6% and a bias of 2.2%, demonstrating very high accuracy of the proposed method.

  20. Improving the Photometry of the Pi of the Sky System

    Directory of Open Access Journals (Sweden)

    A. F. Żarnecki

    2011-01-01

    Full Text Available The “Pi of the Sky” robotic telescope was designed to monitor a significant fraction of the sky with good time resolution and range. The main goal of the “Pi of the Sky” detector is to look for short timescale optical transients arising from various astrophysical phenomena, mainly for the optical counterparts of Gamma Ray Bursts (GRB. The system design, the observation methodology and the algorithms that have been developed make this detector a sophisticated instrument for looking for novae and supernovae stars and for monitoring blasars and AGNs activity. The final detector will consist of two sets of 12 cameras, one camera covering a field of view of 20◦ ×20◦. For data taken with the prototype detector at the Las Campanas Observatory, Chile, photometry uncertainty of 0.018–0.024 magnitudo for stars 7–10m was obtained. With a new calibration algorithm taking into account the spectral type of reference stars, the stability of the photometry algorithm can be significantly improved. Preliminary results from the BGInd variable are presented, showing that uncertainty of the order of 0.013 can be obtained.

  1. Environments of Nearby Quasars in Sloan Digital Sky Survey

    CERN Document Server

    Lietzen, H; Nurmi, P; Tago, E; Saar, E; Liivamagi, J; Tempel, E; Einasto, M; Einasto, J; Gramann, M; Takalo, L O

    2009-01-01

    For the first time spectroscopic galaxy redshift surveys are reaching the scales where galaxies can be studied together with the nearest quasars. This gives an opportunity to study the dependence between the activity of a quasar and its environment in a more extensive way than before. We study the spatial distribution of galaxies and groups of galaxies in the environments of low redshift quasars in the Sloan Digital Sky Survey (SDSS). Our aim is to understand how the nearby quasars are embedded in the local and global density field of galaxies and how the environment affects quasar activity. We analyse the environments of nearby quasars using number counts of galaxies. We also study the dependence of group properties to their distance to the nearest quasar. The large scale environments are studied by analysing the locations of quasars in the luminosity density field. Our study of the number counts of galaxies in quasar environments shows an underdensity of bright galaxies at a few Mpc from quasars. Also, the ...

  2. The cosmological principle is not in the sky

    CERN Document Server

    Park, Chan-Gyung; Noh, Hyerim; Hwang, Jai-chan

    2016-01-01

    The homogeneity of matter distribution at large scales is a central assumption in the standard cosmological model. The case is testable though, thus no longer needs to be a principle, and indeed there have been claims that the distribution of galaxies is homogeneous at radius scales larger than 70 Mpc/h. Here we perform a test for homogeneity using the Sloan Digital Sky Survey Luminous Red Galaxies (LRG) sample by counting galaxies within a specified volume with the radius scale varying up to 300 Mpc/h. Our analysis differs from the previous ones in that we directly confront the large-scale structure data with the definition of spatial homogeneity by comparing the fluctuations of individual number counts with allowed ranges of the random distribution with homogeneity. The LRG sample shows much larger fluctuations of number counts than the random catalogs up to 300 Mpc/h scale, and even the average is located far outside the range allowed in the random distribution, which implies that the cosmological principl...

  3. Ensemble Properties of Comets in the Sloan Digital Sky Survey

    Energy Technology Data Exchange (ETDEWEB)

    Solontoi, Michael; /Adler Planetarium, Chicago; Ivezic, Zeljko; /Washington U., Seattle, Astron. Dept.; Juric, Mario; /Harvard Coll. Observ.; Becker, Andrew C.; /Washington U., Seattle, Astron. Dept.; Jones, Lynne; /Washington U., Seattle, Astron. Dept.; West, Andrew A.; /Boston U.; Kent, Steve; /Fermilab; Lupton, Robert H.; /Princeton U. Observ.; Claire, Mark; /Washington U., Seattle, Astron. Dept.; Knapp, Gillian R.; /Princeton U. Observ.; Quinn, Tom; /Washington U., Seattle, Astron. Dept. /Princeton U. Observ.

    2012-02-01

    We present the ensemble properties of 31 comets (27 resolved and 4 unresolved) observed by the Sloan Digital Sky Survey (SDSS). This sample of comets represents about 1 comet per 10 million SDSS photometric objects. Five-band (u, g, r, i, z) photometry is used to determine the comets colors, sizes, surface brightness profiles, and rates of dust production in terms of the Afp formalism. We find that the cumulative luminosity function for the Jupiter Family Comets in our sample is well fit by a power law of the form N(show an extremely narrow distribution of colors (0.57 {+-} 0.05 in g - r for example), which are statistically indistinguishable from that of the Jupiter Trojans. Further, there is no evidence of correlation between color and physical, dynamical, or observational parameters for the observed comets.

  4. First on-sky demonstration of the piezoelectric adaptive secondary mirror.

    Science.gov (United States)

    Guo, Youming; Zhang, Ang; Fan, Xinlong; Rao, Changhui; Wei, Ling; Xian, Hao; Wei, Kai; Zhang, Xiaojun; Guan, Chunlin; Li, Min; Zhou, Luchun; Jin, Kai; Zhang, Junbo; Deng, Jijiang; Zhou, Longfeng; Chen, Hao; Zhang, Xuejun; Zhang, Yudong

    2016-12-15

    We propose using a piezoelectric adaptive secondary mirror (PASM) in the medium-sized adaptive telescopes with a 2-4 m aperture for structure and control simplification by utilizing the piezoelectric actuators in contrast with the voice-coil adaptive secondary mirror. A closed-loop experimental setup was built for on-sky demonstration of the 73-element PASM developed by our laboratory. In this Letter, the PASM and the closed-loop adaptive optics system are introduced. High-resolution stellar images were obtained by using the PASM to correct high-order wavefront errors in May 2016. To the best of our knowledge, this is the first successful on-sky demonstration of the PASM. The results show that with the PASM as the deformable mirror, the angular resolution of the 1.8 m telescope can be effectively improved.

  5. Surveying and Monitoring of Cultural Heritage: The Role of COSMO-SkyMed Mission

    Science.gov (United States)

    Sacco, Patrizia; Battagliere, Maria Libera; Daraio, Maria Girolamo; Coletta, Alessandro

    2016-08-01

    Early applications of SAR in archaeology date back to the 1980s and, although being mainly demonstrative experimentations, they enabled numerous important discoveries. With the development of Synthetic Aperture Radar (SAR) in terms of multi-band, multi- polarization and high-resolution data, space radar remote sensing for archaeology has become a potential field for research. Although the archaeological detection capability of this technology has so far not been fully assessed, the advent of Very High Resolution (VHR) space borne SAR sensors, such as Italian COSMO- SkyMed, offered advanced mapping capability at high resolution for archaeology investigations. This paper aims to give an overview of the contribution provided by the COSMO-SkyMed mission in the framework of specific projects in which SAR X-band data have been exploited for the monitoring and the management of cultural and archeological heritage, showing some obtained results.

  6. Error analysis in cross-correlation of sky maps: application to the ISW detection

    CERN Document Server

    Cabre, A; Manera, E G M; Cabre, Anna; Fosalba, Pablo; Manera, Enrique Gaztanaga & Marc

    2007-01-01

    Constraining cosmological parameters from measurements of the Integrated Sachs-Wolfe effect requires developing robust and accurate methods for computing statistical errors in the cross-correlation between maps. This paper presents a detailed comparison of such error estimation applied to the case of cross-correlation of Cosmic Microwave Background (CMB) and large-scale structure data. We compare theoretical models for error estimation with montecarlo simulations where both the galaxy and the CMB maps vary around a fiducial auto-correlation and cross-correlation model which agrees well with the current concordance LCDM cosmology. Our analysis compares estimators both in harmonic and configuration (or real) space, quantifies the accuracy of the error analysis and discuss the impact of partial sky survey area and the choice of input fiducial model on dark-energy constraints. We show that purely analytic approaches yield accurate errors even in surveys that cover only 10% of the sky and that parameter constraint...

  7. Phenological Characterization of Desert Sky Island Vegetation Communities with Remotely Sensed and Climate Time Series Data

    Directory of Open Access Journals (Sweden)

    Stuart E. Marsh

    2010-01-01

    Full Text Available Climate change and variability are expected to impact the synchronicity and interactions between the Sonoran Desert and the forested sky islands which represent steep biological and environmental gradients. The main objectives were to examine how well satellite greenness time series data and derived phenological metrics (e.g., season start, peak greenness can characterize specific vegetation communities across an elevation gradient, and to examine the interactions between climate and phenological metrics for each vegetation community. We found that representative vegetation types (11, varying between desert scrub, mesquite, grassland, mixed oak, juniper and pine, often had unique seasonal and interannual phenological trajectories and spatial patterns. Satellite derived land surface phenometrics (11 for each of the vegetation communities along the cline showed numerous distinct significant relationships in response to temperature (4 and precipitation (7 metrics. Satellite-derived sky island vegetation phenology can help assess and monitor vegetation dynamics and provide unique indicators of climate variability and patterns of change.

  8. Foreground removal from Planck Sky Model temperature maps using a MLP neural network

    DEFF Research Database (Denmark)

    Nørgaard-Nielsen, Hans Ulrik; Hebert, K.

    2009-01-01

    Unfortunately, the Cosmic Microwave Background (CMB) radiation is contaminated by emission originating in the Milky Way (synchrotron, free-free and dust emission). Since the cosmological information is statistically in nature, it is essential to remove this foreground emission and leave the CMB...... with no systematic errors. To demonstrate the feasibility of a simple multilayer perceptron (MLP) neural network for extracting the CMB temperature signal, we have analyzed a specific data set, namely the Planck Sky Model maps, developed for evaluation of different component separation methods before including them...... in the Planck data analysis pipeline. It is found that a MLP neural network can provide a CMB map of about 80% of the sky to a very high degree uncorrelated with the foreground components. Also the derived power spectrum shows little evidence for systematic errors....

  9. The Research Search For The Least Beneficial Overcast Sky And Progress In Defining Its Luminance Gradation Function

    Directory of Open Access Journals (Sweden)

    Kittler R.

    2014-09-01

    Full Text Available Recently illuminance levels under ISO/CIE homogeneous standard sky types were characterised in their relative terms after ISO/CIE (2004, 2003 standardised as normalised by the luminance in the zenith. Sky luminance and horizontal illuminance based on the gradation and scattering indicatrix functions, including the extreme overcast cases frequently encountered in nature, were recently determined in absolute physical units of luminance in kilocandles per meter square and of illuminance in kilolux. The historical search to find energy and visibility critical sky luminance distributions shows a progression of steps in studying the worst or critical overcast situations. That progression has enabled the determination and evaluation of interior illuminance for comparison of the merits of dual daylighting and artificial lighting under established criteria for comfortable visibility.

  10. Assessment of a Technique for Estimating Total Column Water Vapor Using Measurements of the Infrared Sky Temperature

    Science.gov (United States)

    Merceret, Francis J.; Huddleston, Lisa L.

    2014-01-01

    A method for estimating the integrated precipitable water (IPW) content of the atmosphere using measurements of indicated infrared zenith sky temperature was validated over east-central Florida. The method uses inexpensive, commercial off the shelf, hand-held infrared thermometers (IRT). Two such IRTs were obtained from a commercial vendor, calibrated against several laboratory reference sources at KSC, and used to make IR zenith sky temperature measurements in the vicinity of KSC and Cape Canaveral Air Force Station (CCAFS). The calibration and comparison data showed that these inexpensive IRTs provided reliable, stable IR temperature measurements that were well correlated with the NOAA IPW observations.

  11. Data analysis of gravitational-wave signals from spinning neutron stars; 4, An all-sky search

    CERN Document Server

    Astone, P; Jaranowski, P; Królak, A; Astone, Pia; Borkowski, Kazimierz M.; Jaranowski, Piotr; Kr\\'olak, Andrzej

    2002-01-01

    We develop a set of data analysis tools for a realistic all-sky search for continuous gravitational-wave signals. The methods that we present apply to data from both the resonant bar detectors that are currently in operation and the laser interferometric detectors that are in the final stages of construction and commissioning. We show that with our techniques we shall be able to perform an all-sky 2-day long coherent search of the narrow-band data from the resonant bar EXPLORER with no loss of signals with the dimensionless amplitude greater than $2.8\\times10^{-23}$.

  12. A Supplementary Clear-Sky Snow and Ice Recognition Technique for CERES Level 2 Products

    Science.gov (United States)

    Radkevich, Alexander; Khlopenkov, Konstantin; Rutan, David; Kato, Seiji

    2013-01-01

    Identification of clear-sky snow and ice is an important step in the production of cryosphere radiation budget products, which are used in the derivation of long-term data series for climate research. In this paper, a new method of clear-sky snow/ice identification for Moderate Resolution Imaging Spectroradiometer (MODIS) is presented. The algorithm's goal is to enhance the identification of snow and ice within the Clouds and the Earth's Radiant Energy System (CERES) data after application of the standard CERES scene identification scheme. The input of the algorithm uses spectral radiances from five MODIS bands and surface skin temperature available in the CERES Single Scanner Footprint (SSF) product. The algorithm produces a cryosphere rating from an aggregated test: a higher rating corresponds to a more certain identification of the clear-sky snow/ice-covered scene. Empirical analysis of regions of interest representing distinctive targets such as snow, ice, ice and water clouds, open waters, and snow-free land selected from a number of MODIS images shows that the cryosphere rating of snow/ice targets falls into 95% confidence intervals lying above the same confidence intervals of all other targets. This enables recognition of clear-sky cryosphere by using a single threshold applied to the rating, which makes this technique different from traditional branching techniques based on multiple thresholds. Limited tests show that the established threshold clearly separates the cryosphere rating values computed for the cryosphere from those computed for noncryosphere scenes, whereas individual tests applied consequently cannot reliably identify the cryosphere for complex scenes.

  13. Mining the SDSS SkyServer SQL queries log

    Science.gov (United States)

    Hirota, Vitor M.; Santos, Rafael; Raddick, Jordan; Thakar, Ani

    2016-05-01

    SkyServer, the Internet portal for the Sloan Digital Sky Survey (SDSS) astronomic catalog, provides a set of tools that allows data access for astronomers and scientific education. One of SkyServer data access interfaces allows users to enter ad-hoc SQL statements to query the catalog. SkyServer also presents some template queries that can be used as basis for more complex queries. This interface has logged over 330 million queries submitted since 2001. It is expected that analysis of this data can be used to investigate usage patterns, identify potential new classes of queries, find similar queries, etc. and to shed some light on how users interact with the Sloan Digital Sky Survey data and how scientists have adopted the new paradigm of e-Science, which could in turn lead to enhancements on the user interfaces and experience in general. In this paper we review some approaches to SQL query mining, apply the traditional techniques used in the literature and present lessons learned, namely, that the general text mining approach for feature extraction and clustering does not seem to be adequate for this type of data, and, most importantly, we find that this type of analysis can result in very different queries being clustered together.

  14. ESA Sky: a new Astronomy Multi-Mission Interface

    CERN Document Server

    Merín, Bruno; Giordano, Fabrizio; Baines, Deborah; Sarmiento, María-Henar; Martí, Belén López; Racero, Elena; Gutiérrez, Raúl; Pollock, Andy; Rosa, Michael; Castellanos, Javier; González, Juan; León, Ignacio; de Landaluce, Iñaki Ortiz; de Teodoro, Pilar; Nieto, Sara; Lennon, Daniel J; Arviset, Christophe; de Marchi, Guido; O'Mullane, William

    2015-01-01

    We present a science-driven discovery portal for all the ESA Astronomy Missions called ESA Sky that allow users to explore the multi-wavelength sky and to seamlessly retrieve science-ready data in all ESA Astronomy mission archives from a web application without prior-knowledge of any of the missions. The first public beta of the service has been released, currently featuring an interface for exploration of the multi-wavelength sky and for single and/or multiple target searches of science-ready imaging data and catalogues. Future releases will enable retrieval of spectra and will have special time-domain exploration features. From a technical point of view, the system offers progressive multi-resolution all-sky projections of full mission datasets using a new generation of HEALPix projections called HiPS, developed at the CDS; detailed geometrical footprints to connect the all-sky mosaics to individual observations; and direct access to science-ready data at the underlying mission-specific science archives.

  15. Central neural coding of sky polarization in insects.

    Science.gov (United States)

    Homberg, Uwe; Heinze, Stanley; Pfeiffer, Keram; Kinoshita, Michiyo; el Jundi, Basil

    2011-03-12

    Many animals rely on a sun compass for spatial orientation and long-range navigation. In addition to the Sun, insects also exploit the polarization pattern and chromatic gradient of the sky for estimating navigational directions. Analysis of polarization-vision pathways in locusts and crickets has shed first light on brain areas involved in sky compass orientation. Detection of sky polarization relies on specialized photoreceptor cells in a small dorsal rim area of the compound eye. Brain areas involved in polarization processing include parts of the lamina, medulla and lobula of the optic lobe and, in the central brain, the anterior optic tubercle, the lateral accessory lobe and the central complex. In the optic lobe, polarization sensitivity and contrast are enhanced through convergence and opponency. In the anterior optic tubercle, polarized-light signals are integrated with information on the chromatic contrast of the sky. Tubercle neurons combine responses to the UV/green contrast and e-vector orientation of the sky and compensate for diurnal changes of the celestial polarization pattern associated with changes in solar elevation. In the central complex, a topographic representation of e-vector tunings underlies the columnar organization and suggests that this brain area serves as an internal compass coding for spatial directions.

  16. The $AKARI$ Far-Infrared All-Sky Survey Maps

    CERN Document Server

    Doi, Yasuo; Ootsubo, Takafumi; Arimatsu, Ko; Tanaka, Masahiro; Kitamura, Yoshimi; Kawada, Mitsunobu; Matsuura, Shuji; Nakagawa, Takao; Morishima, Takahiro; Hattori, Makoto; Komugi, Shinya; White, Glenn J; Ikeda, Norio; Kato, Daisuke; Chinone, Yuji; Etxaluze, Mireya; Figueredo, Elysandra

    2015-01-01

    We present a far-infrared all-sky atlas from a sensitive all-sky survey using the Japanese $AKARI$ satellite. The survey covers $> 99$% of the sky in four photometric bands centred at 65 $\\mu$m, 90 $\\mu$m, 140 $\\mu$m, and 160 $\\mu$m with spatial resolutions ranging from 1 to 1.5 arcmin. These data provide crucial information for the investigation and characterisation of the properties of dusty material in the Interstellar Medium (ISM), since significant portion of its energy is emitted between $\\sim$50 and 200 $\\mu$m. The large-scale distribution of interstellar clouds, their thermal dust temperatures and column densities, can be investigated with the improved spatial resolution compared to earlier all-sky survey observations. In addition to the point source distribution, the large-scale distribution of ISM cirrus emission, and its filamentary structure, are well traced. We have made the first public release of the full-sky data to provide a legacy data set for use by the astronomical community.

  17. The AKARI far-infrared all-sky survey maps

    Science.gov (United States)

    Doi, Yasuo; Takita, Satoshi; Ootsubo, Takafumi; Arimatsu, Ko; Tanaka, Masahiro; Kitamura, Yoshimi; Kawada, Mitsunobu; Matsuura, Shuji; Nakagawa, Takao; Morishima, Takahiro; Hattori, Makoto; Komugi, Shinya; White, Glenn J.; Ikeda, Norio; Kato, Daisuke; Chinone, Yuji; Etxaluze, Mireya; Cypriano, Elysandra F.

    2015-06-01

    We present a far-infrared all-sky atlas from a sensitive all-sky survey using the Japanese AKARI satellite. The survey covers > 99% of the sky in four photometric bands centred at 65 μm, 90 μm, 140 μm, and 160 μm, with spatial resolutions ranging from 1' to 1{^''.}5. These data provide crucial information on the investigation and characterisation of the properties of dusty material in the interstellar medium (ISM), since a significant portion of its energy is emitted between ˜ 50 and 200 μm. The large-scale distribution of interstellar clouds, their thermal dust temperatures, and their column densities can be investigated with the improved spatial resolution compared to earlier all-sky survey observations. In addition to the point source distribution, the large-scale distribution of ISM cirrus emission, and its filamentary structure, are well traced. We have made the first public release of the full-sky data to provide a legacy data set for use in the astronomical community.

  18. Night sky brightness at San Pedro Martir Observatory

    CERN Document Server

    Plauchu-Frayn, I; Colorado, E; Herrera, J; Cordova, A; Cesena, U; Avila, F

    2016-01-01

    We present optical UBVRI zenith night sky brightness measurements collected on eighteen nights during 2013--2016 and SQM measurements obtained daily over twenty months during 2014--2016 at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN-SPM) in Mexico. The UBVRI data is based upon CCD images obtained with the 0.84m and 2.12m telescopes, while the SQM data is obtained with a high-sensitivity, low-cost photometer. The typical moonless night sky brightness at zenith averaged over the whole period is U = 22.68, B = 23.10, V = 21.84, R = 21.04, I = 19.36, and SQM = 21.88 mag/square arcsec, once corrected for zodiacal light. We find no seasonal variation of the night sky brightness measured with the SQM. The typical night sky brightness values found at OAN-SPM are similar to those reported for other astronomical dark sites at a similar phase of the solar cycle. We find a trend of decreasing night sky brightness with decreasing solar activity during period of the observations. This trend im...

  19. Artificial neural network (ANN) method for modeling of sunset yellow dye adsorption using zinc oxide nanorods loaded on activated carbon: Kinetic and isotherm study.

    Science.gov (United States)

    Maghsoudi, M; Ghaedi, M; Zinali, A; Ghaedi, A M; Habibi, M H

    2015-01-05

    In this research, ZnO nanoparticle loaded on activated carbon (ZnO-NPs-AC) was synthesized simply by a low cost and nontoxic procedure. The characterization and identification have been completed by different techniques such as SEM and XRD analysis. A three layer artificial neural network (ANN) model is applicable for accurate prediction of dye removal percentage from aqueous solution by ZnO-NRs-AC following conduction of 270 experimental data. The network was trained using the obtained experimental data at optimum pH with different ZnO-NRs-AC amount (0.005-0.015 g) and 5-40 mg/L of sunset yellow dye over contact time of 0.5-30 min. The ANN model was applied for prediction of the removal percentage of present systems with Levenberg-Marquardt algorithm (LMA), a linear transfer function (purelin) at output layer and a tangent sigmoid transfer function (tansig) in the hidden layer with 6 neurons. The minimum mean squared error (MSE) of 0.0008 and coefficient of determination (R(2)) of 0.998 were found for prediction and modeling of SY removal. The influence of parameters including adsorbent amount, initial dye concentration, pH and contact time on sunset yellow (SY) removal percentage were investigated and optimal experimental conditions were ascertained. Optimal conditions were set as follows: pH, 2.0; 10 min contact time; an adsorbent dose of 0.015 g. Equilibrium data fitted truly with the Langmuir model with maximum adsorption capacity of 142.85 mg/g for 0.005 g adsorbent. The adsorption of sunset yellow followed the pseudo-second-order rate equation.

  20. Diagnosis of clear sky ultraviolet radiation for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lemus Deschamps, L. [Bureau of Meteorology Research Centre (Australia); Galindo, I.; Solano, R.; Elizalde, A.T.; Fonseca, J. [Centro Universitario de Investigaciones en Ciencias del Ambiente, University of Colima (Mexico)

    2002-07-01

    A discrete-ordinate radiative transfer model is employed to develop a regional clear sky ultraviolet (UV) diagnosis system. The clear sky UV radiation, weighted by the spectral sensitivity of human skin is calculated using the Total Ozone Mapping Spectrometer (TOMS) data sets. Examples of the geographical clear sky UV Index distributions are presented and the model results are compared with surface UV measurements from University of Colima for 1999. [Spanish] Utilizando un modelo de transferencia de radiacion de ordenadas discretas se desarrolla un sistema para el diagnostico de la distribucion de radiacion ultravioleta para cielo despejado en la Republica Mexicana. La radiacion para cielo despejado se obtiene utilizando la respuesta espectral de la piel humana y los datos de satelite de ozono total registrados por el espectrometro TOMS. Se presentan ejemplos del Indice de radiacion ultravioleta (UV Index) calculados con el modelo y se comparan con las mediciones en superficie obtenidas en la Universidad de Colima durante 1999.