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Sample records for lenses kepler gave

  1. Kepler

    CERN Document Server

    Caspar, Max

    1993-01-01

    A towering figure in intellectual history and one of the fathers of modern astronomy, the great mathematician Johannes Kepler (1571–1630) is best known for his discovery of the three laws of planetary motion, which paved the way for a dynamic explanation of the heavenly phenomena. At a time when the Ptolemaic view still prevailed in official circles, Kepler undertook to prove the truth of the Copernican world view and through exceptional perseverance and force of intellect achieved that goal. His epochal intellectual feats are completely and thoroughly described in this splendid work, considered the definitive biography of Kepler. Drawing on a wealth of primary sources, the author presents a fascinating and erudite picture of Kepler's scientific accomplishments, his public life (work with Tycho Brahe, the Danish astronomer; mathematical appointments at Graz, Prague, and Linz; pioneering work with calculus and optics, and more) and his personal life: childhood and youth, financial situation, his mother's tri...

  2. Kepler-9

    DEFF Research Database (Denmark)

    Holman...[], Matthew J.; Fabrycky, D. C.; Ragozzine, D.

    2010-01-01

    The Kepler spacecraft is monitoring more than 150,000 stars for evidence of planets transiting those stars. We report the detection of two Saturn-size planets that transit the same Sun-like star, based on 7 months of Kepler observations. Their 19.2- and 38.9-day periods are presently increasing...

  3. Kepler Archive Manual

    Science.gov (United States)

    Thompson, Susan E.; Fraquelli, Dorothy; Van Cleve, Jeffrey E.; Caldwell, Douglas A.

    2016-01-01

    A description of Kepler, its design, performance and operational constraints may be found in the Kepler Instrument Handbook (KIH, Van Cleve Caldwell 2016). A description of Kepler calibration and data processing is described in the Kepler Data Processing Handbook (KDPH, Jenkins et al. 2016; Fanelli et al. 2011). Science users should also consult the special ApJ Letters devoted to early Kepler results and mission design (April 2010, ApJL, Vol. 713 L79-L207). Additional technical details regarding the data processing and data qualities can be found in the Kepler Data Characteristics Handbook (KDCH, Christiansen et al. 2013) and the Data Release Notes (DRN). This archive manual specifically documents the file formats, as they exist for the last data release of Kepler, Data Release 25(KSCI-19065-002). The earlier versions of the archive manual and data release notes act as documentation for the earlier versions of the data files.

  4. KEPLER-424 b

    DEFF Research Database (Denmark)

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas

    2014-01-01

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive...

  5. How oxygen gave rise to eukaryotic sex

    NARCIS (Netherlands)

    Hörandl, Elvira; Speijer, Dave

    2018-01-01

    9years ago. The large amount of ROS coming from a bacterial endosymbiont gave rise to DNA damage and vast increases in host genome mutation rates. Eukaryogenesis and chromosome evolution represent adaptations to oxidative stress. The host, an archaeon, most probably already had repair mechanisms

  6. KEPLER SCIENCE OPERATIONS

    International Nuclear Information System (INIS)

    Haas, Michael R.; Bryson, Steve T.; Dotson, Jessie L.; Koch, David G.; Smith, Marcie; Sobeck, Charles K.; Batalha, Natalie M.; Caldwell, Douglas A.; Jenkins, Jon M.; Van Cleve, Jeffrey E.; Hall, Jennifer; Klaus, Todd C.; Middour, Chris; Thompson, Richard S.; Kolodziejczak, Jeffrey; Stober, Jeremy

    2010-01-01

    Kepler's mission design includes a comprehensive plan for commissioning and science operations. The commissioning phase completed all critical tasks and accomplished all mission objectives within a week of the pre-launch plan. Since the start of science data collection, the nominal timeline has been interrupted by two safe-mode events, several losses of fine point, and some small pointing adjustments. The most important anomalies are understood and mitigated, so Kepler's technical performance has improved significantly over this period, and the prognosis for mission success is excellent. The Kepler data archive is established and hosting data for the science team, guest observers, and the public. The first data to become publicly available include the monthly full-frame images and the light curves for targets that are dropped from the exoplanet program or released after publication. Data are placed in the archive on a quarterly basis; the Kepler Results Catalog will be released annually starting in 2011.

  7. Johannes Kepler on Christmas

    Science.gov (United States)

    Kemp, Martin

    2009-12-01

    Kepler's interpretation of the supernova of 1604, De Stella Nova, interwove the science of astronomy with astrology and theology in an attempt to determine the correct birthdate of Jesus, explains Martin Kemp.

  8. The Kepler Asteroseismic Investigation

    DEFF Research Database (Denmark)

    Kjeldsen, Hans

    2011-01-01

    The aim of asteroseismology is to probe the interiors of stars and quantify their properties, such as radius, mass, rotation and age, through observations of oscillation modes. Using the ultrahigh photometric precision and the extended length of the time series from Kepler one can perform...... asteroseismology which is orders of magnitudes more accurate than one could do just a few years ago. The Kepler asteroseismic programme is being conducted through the Kepler Asteroseismic Science Consortium (KASC), whose 400 members are organized into 13 working groups (KASC WGs) by type of variable star. The KASC...... WGs are established to ensure an efficient and structured work within KASC focusing on data analysis, stellar modelling and publication of data. The goals of the asteroseismic part of the Kepler project are to perform detailed studies of stellar interiors and to support the exoplanet investigation...

  9. On Kepler's First Law

    Indian Academy of Sciences (India)

    law of areas follows and Kepler's second law is explained. Note that all that the proof requires is that the force be a .... planation of Kepler's third law: if 2a is the major axis of the orbit (an ellipse, by the second law) and T the .... tors, but he describes it in geometrical language. Let po- sition vectors be measured with reference ...

  10. Gravitational lensing

    CERN Document Server

    Dodelson, Scott

    2017-01-01

    Gravitational lensing is a consequence of general relativity, where the gravitational force due to a massive object bends the paths of light originating from distant objects lying behind it. Using very little general relativity and no higher level mathematics, this text presents the basics of gravitational lensing, focusing on the equations needed to understand the phenomena. It then applies them to a diverse set of topics, including multiply imaged objects, time delays, extrasolar planets, microlensing, cluster masses, galaxy shape measurements, cosmic shear, and lensing of the cosmic microwave background. This approach allows undergraduate students and others to get quickly up to speed on the basics and the important issues. The text will be especially relevant as large surveys such as LSST and Euclid begin to dominate the astronomical landscape. Designed for a one semester course, it is accessible to anyone with two years of undergraduate physics background.

  11. Kepler and Mach's Principle

    Science.gov (United States)

    Barbour, Julian

    The definitive ideas that led to the creation of general relativity crystallized in Einstein's thinking during 1912 while he was in Prague. At the centenary meeting held there to mark the breakthrough, I was asked to talk about earlier great work of relevance to dynamics done at Prague, above all by Kepler and Mach. The main topics covered in this chapter are: some little known but basic facts about the planetary motions; the conceptual framework and most important discoveries of Ptolemy and Copernicus; the complete change of concepts that Kepler introduced and their role in his discoveries; the significance of them in Newton's work; Mach's realization that Kepler's conceptual revolution needed further development to free Newton's conceptual world of the last vestiges of the purely geometrical Ptolemaic world view; and the precise formulation of Mach's principle required to place GR correctly in the line of conceptual and technical evolution that began with the ancient Greek astronomers.

  12. Acoustic lenses

    International Nuclear Information System (INIS)

    Kittmer, C.A.

    1983-03-01

    Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

  13. Kepler: A Search for Terrestrial Planets - Kepler Data Characterization Handbook

    Science.gov (United States)

    Van Cleve, Jeffrey; Christiansen, J. L.; Jenkins, J. M.; Caldwell, D. A.; Barclay, T.; Bryson, S. T.; Burke, C. J.; Campbell, J.; Catanzarite, J.; Clarke, B. D.; hide

    2016-01-01

    The Kepler Data Characteristics Handbook (KDCH) provides a description of all phenomena identified in the Kepler data throughout the mission, and an explanation for how these characteristics are handled by the final version of the Kepler Data Processing Pipeline (SOC 9.3).The KDCH complements the Kepler Data Release Notes (KDRNs), which document phenomena and processing unique to a data release. The original motivation for this separation into static, explanatory text and a more journalistic set of figures and tables in the KDRN was for the user to become familiar with the Data Characteristics Handbook, then peruse the short Notes for a new quarter, referring back to the Handbook when necessary. With the completion of the Kepler mission and the final Data Release 25, both the KDCH and the DRN encompass the entire Kepler mission, so the distinction between them is in the level of exposition, not the extent of the time interval discussed.

  14. Kepler on Light and Sound

    Science.gov (United States)

    Duncan, Alistair

    The works by Johannes Kepler on light ("Paralipomena ad Vitelionem" and "Dioptrice") and sound ("Harmonices Mundi") are reviewed. The author underlines that the "Harmonices Mundi" represents a dissertation on musical theory. Kepler assumed, that the human soul got pleasure from musical harmonies received through the ear, and indeed a succession of notes at melodic intervals, because the human mind perceived the ordained mathematically harmonic relationships between the notes. The contribution of Kepler in the understanding of the phenomenon of resonance is pointed out. Some mistakes by Kepler are also examined.

  15. Kepler's first rocky planet

    DEFF Research Database (Denmark)

    Batalha, N.M.; Borucki, W.J.; Bryson, S.T.

    2011-01-01

    to its rocky composition: M P = 4.56+1.17 -1.29 M ⊕, R P = 1.416+0.033 -0.036 R ⊕, and ρP = 8.8+2.1 -2.9 g cm-3. Kepler-10b is the smallest transiting exoplanet discovered to date. Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California...

  16. Fractals and the Kepler equation

    Science.gov (United States)

    Kasten, Volker

    1992-09-01

    The application of fractal mathematics to Kepler's equation is addressed. Complex solutions to Kepler's equation are considered along with methods to determine them. The roles of regions of attraction and their boundaries, Julia quantities, Fatou quantities, and fractal quantities in these methods are discussed.

  17. Asteroseismology with Kepler and SONG

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J.

    2012-01-01

    The NASA Kepler mission was designed to characterise extra-solar planetary systems but the observing technique, photometric detection of transits, makes the mission ideally suited also for asteroseismology. Since the launch of the mission in March 2009 Kepler has provided a treasure trove...

  18. Transiting circumbinary planets Kepler-34 b and Kepler-35 b.

    Science.gov (United States)

    Welsh, William F; Orosz, Jerome A; Carter, Joshua A; Fabrycky, Daniel C; Ford, Eric B; Lissauer, Jack J; Prša, Andrej; Quinn, Samuel N; Ragozzine, Darin; Short, Donald R; Torres, Guillermo; Winn, Joshua N; Doyle, Laurance R; Barclay, Thomas; Batalha, Natalie; Bloemen, Steven; Brugamyer, Erik; Buchhave, Lars A; Caldwell, Caroline; Caldwell, Douglas A; Christiansen, Jessie L; Ciardi, David R; Cochran, William D; Endl, Michael; Fortney, Jonathan J; Gautier, Thomas N; Gilliland, Ronald L; Haas, Michael R; Hall, Jennifer R; Holman, Matthew J; Howard, Andrew W; Howell, Steve B; Isaacson, Howard; Jenkins, Jon M; Klaus, Todd C; Latham, David W; Li, Jie; Marcy, Geoffrey W; Mazeh, Tsevi; Quintana, Elisa V; Robertson, Paul; Shporer, Avi; Steffen, Jason H; Windmiller, Gur; Koch, David G; Borucki, William J

    2012-01-11

    Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars (binaries). Although long anticipated, the existence of a 'circumbinary planet' orbiting such a pair of normal stars was not definitively established until the discovery of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary planets: Kepler-34 (AB)b and Kepler-35 (AB)b, referred to here as Kepler-34 b and Kepler-35 b, respectively. Each is a low-density gas-giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289 days, whereas Kepler-35 b orbits a pair of smaller stars (89% and 81% of the Sun's mass) every 131 days. The planets experience large multi-periodic variations in incident stellar radiation arising from the orbital motion of the stars. The observed rate of circumbinary planets in our sample implies that more than ∼1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.

  19. Kepler-6b

    DEFF Research Database (Denmark)

    Dunham..[], Edward W.; Borucki, W. J.; Koch, D. G.

    2010-01-01

    We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, . The planet's mass is about 2/3 that of Jupiter, M P = 0.67 M J, and the radius is 30% larger than that of Jupiter, R P = 1.32 R J, resulting in a density of ¿P = 0.35 g cm–3, a fairly...... typical value for such a planet. The orbital period is P = 3.235 days. The host star is both more massive than the Sun, M = 1.21 M , and larger than the Sun, R = 1.39 R...

  20. Kepler planet-detection mission

    DEFF Research Database (Denmark)

    Borucki...[], William J.; Koch, David; Buchhave, Lars C. Astrup

    2010-01-01

    The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are suitable for water to exist on a planet’s surface. During the first 6 weeks of observations, Kepler...... is one of the lowest-density planets (~0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets....

  1. NASA 3D Models: Kepler

    Data.gov (United States)

    National Aeronautics and Space Administration — The Kepler Mission is specifically designed to survey a portion of our region of the Milky Way galaxy to discover Earth-sized planets in or near the habitable zones...

  2. Nyt planetsystem opdaget af Kepler

    DEFF Research Database (Denmark)

    Buchhave, Lars C. Astrup

    2010-01-01

    Ved hjælp af NASA-satellitten Kepler har astronomerne fundet to planeter, der kredser om en fjern stjerne. Der er muligvis også en tredje planet, der ikke er meget større end Jorden......Ved hjælp af NASA-satellitten Kepler har astronomerne fundet to planeter, der kredser om en fjern stjerne. Der er muligvis også en tredje planet, der ikke er meget større end Jorden...

  3. Kepler-22b

    DEFF Research Database (Denmark)

    Borucki, William J.; Koch, David G.; Batalha, Natalie

    2012-01-01

    with an asteroseismic analysis of the Kepler photometry, leading to an estimated mass and radius of 0.970 ± 0.060 M sun and 0.979 ± 0.020 R sun. The depth of 492 ± 10 ppm for the three observed transits yields a radius of 2.38 ± 0.13 Re for the planet. The system passes a battery of tests for false positives, including...... reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A full BLENDER analysis provides further validation of the planet interpretation by showing that contamination of the target by an eclipsing system would rarely mimic the observed shape of the transits. The final validation of the planet...

  4. Kepler-7b

    DEFF Research Database (Denmark)

    Latham...[], David W.; Borucki, W.J.; Koch, D.G.

    2010-01-01

    for an extrasolar planet. The orbital period is fairly long, P = 4.886 days, and the host star is not much hotter than the Sun, T eff = 6000 K. However, it is more massive and considerably larger than the Sun, M = 1.35 M and R = 1.84 R , and must be near the end of its life on the main sequence......We report on the discovery and confirmation of Kepler-7b, a transiting planet with unusually low density. The mass is less than half that of Jupiter, M P = 0.43 M J, but the radius is 50% larger, R P = 1.48 R J. The resulting density, ¿P = 0.17 g cm–3, is the second lowest reported so far...

  5. Transiting circumbinary planets Kepler-34 b and Kepler-35 b

    Energy Technology Data Exchange (ETDEWEB)

    Welsh, William F.; Orosz, Jerome A.; Carter, Joshua A.; Fabrycky, Daniel C.; Ford, Eric B.; Lissauer, Jack J.; Prša, Andrej; Quinn, Samuel N.; Ragozzine, Darin; Short, Donald R.; Torres, Guillermo; Winn, Joshua N.; Doyle, Laurance R.; Barclay, Thomas; Batalha, Natalie; Bloemen, Steven; Brugamyer, Erik; Buchhave, Lars A.; Caldwell, Caroline; Caldwell, Douglas A.; Christiansen, Jessie L.; Ciardi, David R.; Cochran, William D.; Endl, Michael; Fortney, Jonathan J.; Gautier III, Thomas N.; Gilliland, Ronald L.; Haas, Michael R.; Hall, Jennifer R.; Holman, Matthew J.; Howard, Andrew W.; Howell, Steve B.; Isaacson, Howard; Jenkins, Jon M.; Klaus, Todd C.; Latham, David W.; Li, Jie; Marcy, Geoffrey W.; Mazeh, Tsevi; Quintana, Elisa V.; Robertson, Paul; Shporer, Avi; Steffen, Jason H.; Windmiller, Gur; Koch, David G.; Borucki, William J.

    2012-01-11

    Most Sun-like stars in the Galaxy reside in gravitationally-bound pairs of stars called 'binary stars'. While long anticipated, the existence of a 'circumbinary planet' orbiting such a pair of normal stars was not definitively established until the discovery of Kepler-16. Incontrovertible evidence was provided by the miniature eclipses ('transits') of the stars by the planet. However, questions remain about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we present two additional transiting circumbinary planets, Kepler-34 and Kepler-35. Each is a low-density gas giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 orbits two Sun-like stars every 289 days, while Kepler-35 orbits a pair of smaller stars (89% and 81% of the Sun's mass) every 131 days. Due to the orbital motion of the stars, the planets experience large multi-periodic variations in incident stellar radiation. The observed rate of circumbinary planets implies > ~1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.

  6. Survey and selection of assessment methodologies for GAVE options

    International Nuclear Information System (INIS)

    Weterings, R.

    1999-05-01

    The Dutch government is interested in the possibilities for a market introduction of new gaseous and liquid energy carriers. To this purpose the GAVE-programme was recently set up. This study is carried out within the framework of the GAVE-programme and aims at the selection of methodologies for assessing the technological, economic, ecological and social perspectives of these new energy options (so-called GAVE-options). Based on the results of these assessments the Dutch ministries of Housing, Planning and Environment (VROM) and Economic Affairs (EZ) will decide at the end of 1999 about starting demonstration projects of promising energy carriers

  7. Kepler observations of Am stars

    DEFF Research Database (Denmark)

    Balona, L. A.; Ripepi, V.; Cantanzaro, G.

    2011-01-01

    We present an analysis of high-resolution spectra for two pulsating Am stars in the Kepler field. The stellar parameters derived in this way are important because parameters derived from narrow-band photometry may be affected by the strong metal lines in these stars. We analyse the Kepler time...... series of ten known Am stars and find that six of them clearly show δ Scuti pulsations. The other four appear to be non-pulsating. We derive fundamental parameters for all known pulsating Am stars from ground-based observations and also for the Kepler Am stars to investigate the location...... of the instability strip for pulsating Am stars. We find that there is not much difference between the Am-star instability strip and the δ Scuti instability strip. We find that the observed location of pulsating Am stars in the HR diagram does not agree with the location predicted from diffusion calculations. Based...

  8. Survey and selection of assessment methodologies for GAVE options; Inventarisatie en selectie van beoordelingsmethodieken voor GAVE-opties

    Energy Technology Data Exchange (ETDEWEB)

    Weterings, R. [ed.] [TNO Milieu, Energie en Procesinnovatie TNO-MEP, Apeldoorn (Netherlands)

    1999-05-01

    The Dutch government is interested in the possibilities for a market introduction of new gaseous and liquid energy carriers. To this purpose the GAVE-programme was recently set up. This study is carried out within the framework of the GAVE-programme and aims at the selection of methodologies for assessing the technological, economic, ecological and social perspectives of these new energy options (so-called GAVE-options). Based on the results of these assessments the Dutch ministries of Housing, Planning and Environment (VROM) and Economic Affairs (EZ) will decide at the end of 1999 about starting demonstration projects of promising energy carriers.

  9. Arcs from gravitational lensing

    Science.gov (United States)

    Grossman, Scott A.; Narayan, Ramesh

    1988-01-01

    The proposal made by Paczynski (1987) that the arcs of blue light found recently in two cluster cores are gravitationally lensed elongated images of background galaxies is investigated. It is shown that lenses that are circularly symmetric in projection produce pairs of arcs, in conflict with the observations. However, more realistic asymmetric lenses produce single arcs, which can become as elongated as the observed ones whenever the background galaxy is located on or close to a cusp caustic. Detailed computer simulations of lensing by clusters using a reasonable model of the mass distribution are presented. Elongated and curved lensed images longer than 10 arcsec occur in 12 percent of the simulated clusters. It is concluded that the lensing hypothesis must be taken seriously.

  10. Gravitational lensing and microlensing

    CERN Document Server

    Mollerach, Silvia

    2002-01-01

    This book provides a comprehensive and self-contained exposition of gravitational lensing phenomena. It presents the up-to-date status of gravitational lensing and microlensing, covering the cosmological applications of the observed lensing by galaxies, clusters and the large scale structures, as well as the microlensing searches in the Local Group and its applications to unveil the nature of the galactic dark matter, the search for planetary objects and the distribution of faint stars in our galaxy. Gravitational Lensing and Microlensing is pitched at the level of the graduate student interes

  11. Kepler photometry of KIC10661783

    DEFF Research Database (Denmark)

    Southworth, J.; Pavlovski, K.; Smalley, B.

    2011-01-01

    We present Kepler satellite photometry of KIC 10661783, a short-period binary star system which shows total eclipses and multiperiodic δ Scuti pulsations. A frequency analysis of the eclipse-subtracted light curve reveals at least 68 frequencies, of which 55 or more can be attributed to pulsation...

  12. Asteroseismology with NASA's Kepler Mission

    DEFF Research Database (Denmark)

    Huber, Daniel; Chaplin, W. J.; Christensen-Dalsgaard, J.

    2013-01-01

    The measurement of stellar oscillations - also called asteroseismology - is among the most powerful observational tools to study the structure and evolution of stars. The high precision photometry collected by the Kepler space telescope has revolutionized asteroseismology over the past few years ...

  13. Learning through Different Lenses

    Science.gov (United States)

    Jeweler, Sue; Barnes-Robinson, Linda

    2015-01-01

    When parents and teachers help gifted kids use the metaphor "learning through different lenses," amazing things happen: Horizons open up. Ideas are focused. Thoughts are magnified and clarified. They see the big picture. Metaphoric thinking offers new and exciting ways to see the world. Viewing the world through different lenses provides…

  14. Variations on a theme by Kepler

    CERN Document Server

    Guillemin, Victor W

    2006-01-01

    This book is based on the Colloquium Lectures presented by Shlomo Sternberg in 1990. The authors delve into the mysterious role that groups, especially Lie groups, play in revealing the laws of nature by focusing on the familiar example of Kepler motion: the motion of a planet under the attraction of the sun according to Kepler's laws. Newton realized that Kepler's second law-that equal areas are swept out in equal times-has to do with the fact that the force is directed radially to the sun. Kepler's second law is really the assertion of the conservation of angular momentum, reflecting the rot

  15. Elementary derivation of Kepler's laws

    International Nuclear Information System (INIS)

    Vogt, E.

    1995-02-01

    A simple derivation of all three so-called Kepler Laws is presented in which the orbits, bound and unbound, follow directly and immediately from conservation of energy and angular momentum. The intent is to make this crowning achievement of Newtonian Mechanics easily accessible to students in introductory physics courses. The method is also extended to simplify the derivation of the Rutherford Scattering Law. (author). 4 refs., 3 figs

  16. Kepler Fine Guidance Sensor Data

    Science.gov (United States)

    Van Cleve, Jeffrey; Campbell, Jennifer Roseanna

    2017-01-01

    The Kepler and K2 missions collected Fine Guidance Sensor (FGS) data in addition to the science data, as discussed in the Kepler Instrument Handbook (KIH, Van Cleve and Caldwell 2016). The FGS CCDs are frame transfer devices (KIH Table 7) located in the corners of the Kepler focal plane (KIH Figure 24), which are read out 10 times every second. The FGS data are being made available to the user community for scientific analysis as flux and centroid time series, along with a limited number of FGS full frame images which may be useful for constructing a World Coordinate System (WCS) or otherwise putting the time series data in context. This document will describe the data content and file format, and give example MATLAB scripts to read the time series. There are three file types delivered as the FGS data.1. Flux and Centroid (FLC) data: time series of star signal and centroid data. 2. Ancillary FGS Reference (AFR) data: catalog of information about the observed stars in the FLC data. 3. FGS Full-Frame Image (FGI) data: full-frame image snapshots of the FGS CCDs.

  17. Inverting Gravitational Lenses

    Science.gov (United States)

    Newbury, P. R.; Spiteri, R. J.

    2002-02-01

    Gravitational lensing provides a powerful tool to study a number of fundamental questions in astrophysics. Fortuitously, one can begin to explore some non-trivial issues associated with this phenomenon without a lot of very sophisticated mathematics, making an elementary treatment of this topic tractable even to senior undergraduates. In this paper, we give a relatively self-contained outline of the basic concepts and mathematics behind gravitational lensing as a recent and exciting topic for courses in mathematical modeling or scientific computing. To this end, we have designed and made available some interactive software to aid in the simulation and inversion of gravitational lenses in a classroom setting.

  18. Stress-Detection Lenses

    Science.gov (United States)

    1996-01-01

    An Ames Research Center scientist invented an infrared lens used in sunglasses to filter out ultraviolet rays. This product finds its origins in research for military enemy detection. Through a Space Act Agreement, Optical Sales Corporation introduced the Hawkeye Lenses not only as sunglasses but as plant stress detection lenses. The lenses enhance the stressed part of the leaf, which has less chlorophyll than healthy leaves, through dyes that filter out certain wavelengths of light. Plant stress is visible earlier, at a stage when something can be done to save the plants.

  19. Planet Detection: The Kepler Mission

    Science.gov (United States)

    Jenkins, Jon M.; Smith, Jeffrey C.; Tenenbaum, Peter; Twicken, Joseph D.; Van Cleve, Jeffrey

    2012-03-01

    The search for exoplanets is one of the hottest topics in astronomy and astrophysics in the twenty-first century, capturing the public's attention as well as that of the astronomical community. This nascent field was conceived in 1989 with the discovery of a candidate planetary companion to HD114762 [35] and was born in 1995 with the discovery of the first extrasolar planet 51 Peg-b [37] orbiting a main sequence star. As of March, 2011, over 500 exoplanets have been discovered* and 106 are known to transit or cross their host star, as viewed from Earth. Of these transiting planets, 15 have been announced by the Kepler Mission, which was launched into an Earth-trailing, heliocentric orbit in March, 2009 [1,4,6,15,18,20,22,31,32,34,36,43]. In addition, over 1200 candidate transiting planets have already been detected by Kepler [5], and vigorous follow-up observations are being conducted to vet these candidates. As the false-positive rate for Kepler is expected to be quite low [39], Kepler has effectively tripled the number of known exoplanets. Moreover, Kepler will provide an unprecedented data set in terms of photometric precision, duration, contiguity, and number of stars. Kepler's primary science objective is to determine the frequency of Earth-size planets transiting their Sun-like host stars in the habitable zone, that range of orbital distances for which liquid water would pool on the surface of a terrestrial planet such as Earth, Mars, or Venus. This daunting task demands an instrument capable of measuring the light output from each of over 100,000 stars simultaneously with an unprecedented photometric precision of 20 parts per million (ppm) at 6.5-h intervals. The large number of stars is required because the probability of the geometrical alignment of planetary orbits that permit observation of transits is the ratio of the size of the star to the size of the planetary orbit. For Earth-like planets in 1-astronomical unit (AU) orbits† about sun-like stars

  20. Gravitational lensing of quasars

    CERN Document Server

    Eigenbrod, Alexander

    2013-01-01

    The universe, in all its richness, diversity and complexity, is populated by a myriad of intriguing celestial objects. Among the most exotic of them are gravitationally lensed quasars. A quasar is an extremely bright nucleus of a galaxy, and when such an object is gravitationally lensed, multiple images of the quasar are produced – this phenomenon of cosmic mirage can provide invaluable insights on burning questions, such as the nature of dark matter and dark energy. After presenting the basics of modern cosmology, the book describes active galactic nuclei, the theory of gravitational lensing, and presents a particular numerical technique to improve the resolution of astronomical data. The book then enters the heart of the subject with the description of important applications of gravitational lensing of quasars, such as the measurement of the famous Hubble constant, the determination of the dark matter distribution in galaxies, and the observation of the mysterious inner parts of quasars with much higher r...

  1. Weakly oval electron lense

    International Nuclear Information System (INIS)

    Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.

    2001-01-01

    The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system

  2. Visualization of Kepler's Laws of Planetary Motion

    Science.gov (United States)

    Lu, Meishu; Su, Jun; Wang, Weiguo; Lu, Jianlong

    2017-01-01

    For this article, we use a 3D printer to print a surface similar to universal gravitation for demonstrating and investigating Kepler's laws of planetary motion describing the motion of a small ball on the surface. This novel experimental method allows Kepler's laws of planetary motion to be visualized and will contribute to improving the…

  3. Measuring Stellar Rotation Periods with Kepler

    DEFF Research Database (Denmark)

    Nielsen, M. B.; Gizon, L.; Schunker, H.

    2013-01-01

    We measure rotation periods for 12151 stars in the Kepler field, based on photometric variability caused by stellar activity. Our analysis returns stable rotation periods over at least six out of eight quarters of Kepler data. This large sample of stars enables us to study rotation periods...

  4. Which of Kepler's Stars Flare?

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    The habitability of distant exoplanets is dependent upon many factors one of which is the activity of their host stars. To learn about which stars are most likely to flare, a recent study examines tens of thousands of stellar flares observed by Kepler.Need for a Broader SampleArtists rendering of a flaring dwarf star. [NASAs Goddard Space Flight Center/S. Wiessinger]Most of our understanding of what causes a star to flare is based on observations of the only star near enough to examine in detail the Sun. But in learning from a sample size of one, a challenge arises: we must determine which conclusions are unique to the Sun (or Sun-like stars), and which apply to other stellar types as well.Based on observations and modeling, astronomers think that stellar flares result from the reconnection of magnetic field lines in a stars outer atmosphere, the corona. The magnetic activity is thought to be driven by a dynamo caused by motions in the stars convective zone.HR diagram of the Kepler stars, with flaring main-sequence (yellow), giant (red) and A-star (green) stars in the authors sample indicated. [Van Doorsselaere et al. 2017]To test whether these ideas are true generally, we need to understand what types of stars exhibit flares, and what stellar properties correlate with flaring activity. A team of scientists led by Tom Van Doorsselaere (KU Leuven, Belgium) has now used an enormous sample of flares observed by Kepler to explore these statistics.Intriguing TrendsVan Doorsselaere and collaborators used a new automated flare detection and characterization algorithm to search through the raw light curves from Quarter 15 of the Kepler mission, building a sample of 16,850 flares on 6,662 stars. They then used these to study the dependence of the flare occurrence rate, duration, energy, and amplitude on the stellar spectral type and rotation period.This large statistical study led the authors to several interesting conclusions, including:Flare star incidence rate as a a

  5. Jacobi-Maupertuis metric and Kepler equation

    Science.gov (United States)

    Chanda, Sumanto; Gibbons, Gary William; Guha, Partha

    This paper studies the application of the Jacobi-Eisenhart lift, Jacobi metric and Maupertuis transformation to the Kepler system. We start by reviewing fundamentals and the Jacobi metric. Then we study various ways to apply the lift to Kepler-related systems: first as conformal description and Bohlin transformation of Hooke’s oscillator, second in contact geometry and third in Houri’s transformation [T. Houri, Liouville integrability of Hamiltonian systems and spacetime symmetry (2016), www.geocities.jp/football_physician/publication.html], coupled with Milnor’s construction [J. Milnor, On the geometry of the Kepler problem, Am. Math. Mon. 90 (1983) 353-365] with eccentric anomaly.

  6. Kepler's Philosophy and the New Astronomy

    CERN Document Server

    Martens, Rhonda

    2009-01-01

    Johannes Kepler contributed importantly to every field he addressed. He changed the face of astronomy by abandoning principles that had been in place for two millennia, made important discoveries in optics and mathematics, and was an uncommonly good philosopher. Generally, however, Kepler's philosophical ideas have been dismissed as irrelevant and even detrimental to his legacy of scientific accomplishment. Here, Rhonda Martens offers the first extended study of Kepler's philosophical views and shows how those views helped him construct and justify the new astronomy.Martens notes that since Ke

  7. K2flix: Kepler pixel data visualizer

    Science.gov (United States)

    Barentsen, Geert

    2015-03-01

    K2flix makes it easy to inspect the CCD pixel data obtained by NASA's Kepler space telescope. The two-wheeled extended Kepler mission, K2, is affected by new sources of systematics, including pointing jitter and foreground asteroids, that are easier to spot by eye than by algorithm. The code takes Kepler's Target Pixel Files (TPF) as input and turns them into contrast-stretched animated gifs or MPEG-4 movies. K2flix can be used both as a command-line tool or using its Python API.

  8. The Kepler follow-up observation program

    DEFF Research Database (Denmark)

    Gautier...[], T.N.; Batalha, N.M.; Borucki, W. J.

    2010-01-01

    The Kepler Mission was launched on March 6, 2009 to perform a photometric survey of more than 100,000 dwarf stars to search for terrestrial-size planets with the transit technique. Follow-up observations of planetary candidates identified by detection of transit-like events are needed both...... for identification of astrophysical phenomena that mimic planetary transits and for characterization of the true planets and planetary systems found by Kepler. We have developed techniques and protocols for detection of false planetary transits and are currently conducting observations on 177 Kepler targets...

  9. Music of the heavens Kepler's harmonic astronomy

    CERN Document Server

    Stephenson, Bruce

    2014-01-01

    Valued today for its development of the third law of planetary motion, Harmonice mundi (1619) was intended by Kepler to expand on ancient efforts to discern a Creator's plan for the planetary system--an arrangement thought to be based on harmonic relationships. Challenging critics who characterize Kepler's theories of harmonic astronomy as ""mystical,"" Bruce Stephenson offers the first thorough technical analysis of the music the astronomer thought the heavens made, and the logic that led him to find musical patterns in his data. In so doing, Stephenson illuminates crucial aspects of Kepler'

  10. Triassic marine reptiles gave birth to live young.

    Science.gov (United States)

    Cheng, Yen-Nien; Wu, Xiao-Chun; Ji, Qiang

    2004-11-18

    Sauropterygians form the largest and most diverse group of ancient marine reptiles that lived throughout nearly the entire Mesozoic era (from 250 to 65 million years ago). Although thousands of specimens of this group have been collected around the world since the description of the first plesiosaur in 1821 (ref. 3), no direct evidence has been found to determine whether any sauropterygians came on shore to lay eggs (oviparity) like sea turtles, or gave birth in the water to live young (viviparity) as ichthyosaurs and mosasauroids (marine lizards) did. Viviparity has been proposed for plesiosaur, pachypleurosaur and nothosaur sauropterygians, but until now no concrete evidence has been advanced. Here we report two gravid specimens of Keichousaurus hui Young from the Middle Triassic of China. These exquisitely preserved specimens not only provide the first unequivocal evidence of reproductive mode and sexual dimorphism in sauropterygians, but also indicate that viviparity could have been expedited by the evolution of a movable pelvis in pachypleurosaurs. By extension, this has implications for the reproductive pattern of other sauropterygians and Mesozoic marine reptiles that possessed a movable pelvis.

  11. NASA 3D Models: Kepler Photometer

    Data.gov (United States)

    National Aeronautics and Space Administration — The Kepler Mission is specifically designed to survey a portion of our region of the Milky Way galaxy to discover Earth-sized planets in or near the habitable zones...

  12. Biocompatibility of Intraocular Lenses.

    Science.gov (United States)

    Özyol, Pelin; Özyol, Erhan; Karel, Fatih

    2017-08-01

    The performance of an intraocular lens is determined by several factors such as the surgical technique, surgical complications, intraocular lens biomaterial and design, and host reaction to the lens. The factor indicating the biocompatibility of an intraocular lens is the behavior of inflammatory and lens epithelial cells. Hence, the biocompatibility of intraocular lens materials is assessed in terms of uveal biocompatibility, based on the inflammatory foreign-body reaction of the eye against the implant, and in terms of capsular biocompatibility, determined by the relationship of the intraocular lens with residual lens epithelial cells within the capsular bag. Insufficient biocompatibility of intraocular lens materials may result in different clinical entities such as anterior capsule opacification, posterior capsule opacification, and lens epithelial cell ongrowth. Intraocular lenses are increasingly implanted much earlier in life in cases such as refractive lens exchange or pediatric intraocular lens implantation after congenital cataract surgery, and these lenses are expected to exhibit maximum performance for many decades. The materials used in intraocular lens manufacture should, therefore, ensure long-term uveal and capsular biocompatibility. In this article, we review the currently available materials used in the manufacture of intraocular lenses, especially with regard to their uveal and capsular biocompatibility, and discuss efforts to improve the biocompatibility of intraocular lenses.

  13. Kepler's third law and the oscillator's isochronism

    Science.gov (United States)

    Gorringe, V. M.; Leach, P. G. L.

    1993-11-01

    Two classes of differential equations which have Kepler-like and oscillatorlike elliptical orbits are shown to have generalizations of the conserved angular momentum, energy, and Laplace-Runge-Lenz vector (Jauch-Hill-Fradkin tensor for the oscillator case). Both possess a generator of self-similar transformations and the related period-semimajor axis relation is a generalization of Kepler's third law in which the constant of proportionality depends explicitly on the eccentricity of the orbit.

  14. Kepler's laws with introduction to differential calculus

    OpenAIRE

    Plakhotnyk, Makar

    2017-01-01

    We explain the solution of the following two problems: obtaining of Kepler's laws from Newton's laws (so called two bodies problem) and obtaining the fourth Newton's law (the formula for gravitation) as a corollary of Kepler's laws. This small book is devoted to the scholars, who are interested in physics and mathematics. We also make a series of digressions, where explain some technique of the higher mathematics, which are used in the proofs.

  15. Kepler

    Data.gov (United States)

    National Aeronautics and Space Administration — The centuries-old quest for other worlds like our Earth has been rejuvenated by the intense excitement and popular interest surrounding the discovery of hundreds of...

  16. Learning unit: Thin lenses

    Science.gov (United States)

    Nita, L.-S.

    2012-04-01

    Learning unit: Thin lenses "Why objects seen through lenses are sometimes upright and sometimes reversed" Nita Laura Simona National College of Arts and Crafts "Constantin Brancusi", Craiova, Romania 1. GEOMETRIC OPTICS. 13 hours Introduction (models, axioms, principles, conventions) 1. Thin lenses (Types of lenses. Defining elements. Path of light rays through lenses. Image formation. Required physical quantities. Lens formulas). 2. Lens systems (Non-collated lenses. Focalless systems). 3. Human eye (Functioning as an optical system. Sight defects and their corrections). 4. Optical instruments (Characteristics exemplified by a magnifying glass. Paths of light rays through a simplified photo camera. Path of light rays through a classical microscope) (Physics curriculum for the IXth grade/ 2011). This scenario exposes a learning unit based on experimental sequences (defining specific competencies), as a succession of lessons started by noticing a problem whose solution assumes the setup of an experiment under laboratory conditions. Progressive learning of theme objectives are realised with sequential experimental steps. The central cognitive process is the induction or the generalization (development of new knowledge based on observation of examples or counterexamples of the concept to be learnt). Pupil interest in theme objectives is triggered by problem-situations, for example: "In order to better see small objects I need a magnifying glass. But when using a magnifier, small object images are sometimes seen upright and sometimes seen reversed!" Along the way, pupils' reasoning will converge to the idea: "The image of an object through a lens depends on the relative distances among object, lens, and observer". Associated learning model: EXPERIMENT Specific competencies: derived from the experiment model, in agreement with the following learning unit steps I. Evoking - Anticipation: Size of the problem, formulation of hypotheses and planning of experiment. II

  17. Kepler AutoRegressive Planet Search

    Science.gov (United States)

    Feigelson, Eric

    NASA's Kepler mission is the source of more exoplanets than any other instrument, but the discovery depends on complex statistical analysis procedures embedded in the Kepler pipeline. A particular challenge is mitigating irregular stellar variability without loss of sensitivity to faint periodic planetary transits. This proposal presents a two-stage alternative analysis procedure. First, parametric autoregressive ARFIMA models, commonly used in econometrics, remove most of the stellar variations. Second, a novel matched filter is used to create a periodogram from which transit-like periodicities are identified. This analysis procedure, the Kepler AutoRegressive Planet Search (KARPS), is confirming most of the Kepler Objects of Interest and is expected to identify additional planetary candidates. The proposed research will complete application of the KARPS methodology to the prime Kepler mission light curves of 200,000: stars, and compare the results with Kepler Objects of Interest obtained with the Kepler pipeline. We will then conduct a variety of astronomical studies based on the KARPS results. Important subsamples will be extracted including Habitable Zone planets, hot super-Earths, grazing-transit hot Jupiters, and multi-planet systems. Groundbased spectroscopy of poorly studied candidates will be performed to better characterize the host stars. Studies of stellar variability will then be pursued based on KARPS analysis. The autocorrelation function and nonstationarity measures will be used to identify spotted stars at different stages of autoregressive modeling. Periodic variables with folded light curves inconsistent with planetary transits will be identified; they may be eclipsing or mutually-illuminating binary star systems. Classification of stellar variables with KARPS-derived statistical properties will be attempted. KARPS procedures will then be applied to archived K2 data to identify planetary transits and characterize stellar variability.

  18. Surface wettability enhancement of silicone hydrogel lenses by processing with polar plastic molds.

    Science.gov (United States)

    Lai, Y C; Friends, G D

    1997-06-05

    In the quest for hydrogel contact lenses with improved extended wear capability, the use of siloxane moieties in the lens materials was investigated. However, the introduction of hydrophobic siloxane groups gave rise to wettability and lipidlike deposit problems. It was found that when polysiloxane-based compositions for hydrogels were processed with polar plastic molds, such as those fabricated from an acrylonitrile-based polymer, the hydrogel lenses fabricated were wettable, with minimized lipidlike deposits. These findings were supported by the wettability of silicone hydrogel films, silicon, and nitrogen element contents near lens surfaces, as well as the results from clinical assessment of silicone hydrogel lenses.

  19. DA white dwarfs in the Kepler field

    Science.gov (United States)

    Doyle, T. F.; Howell, S. B.; Petit, V.; Lépine, S.

    2017-01-01

    We present 16 new, and confirm 7 previously identified, DA white dwarfs in the Kepler field through ground-based spectroscopy with the Hale 200″, Kitt Peak 4-m, and Bok 2.3-m telescopes. Using atmospheric models, we determine their effective temperatures and surface gravities to constrain their position with respect to the ZZ Ceti (DA pulsator) instability strip, and look for the presence or absence of pulsation with Kepler's unprecedented photometry. Our results are as follows. (I) From our measurements of temperature and surface gravity, 12 of the 23 DA white dwarfs from this work fall well outside of the instability strip. The Kepler photometry available for 11 of these WDs allows us to confirm that none are pulsating. One of these 11 happens to be a presumed binary, KIC 11604781, with a period of ˜5 d. (II) The remaining 11 DA white dwarfs are instability strip candidates, potentially falling within the current, empirical instability strip, after accounting for uncertainties. These WDs will help constrain the strip's location further, as eight are near the blue edge and three are near the red edge of the instability strip. Four of these WDs do not have Kepler photometry, so ground-based photometry is needed to determine the pulsation nature of these white dwarfs. The remaining seven have Kepler photometry available, but do not show any periodicity on typical WD pulsation time-scales.

  20. Mining the Kepler Data using Machine Learning

    Science.gov (United States)

    Walkowicz, Lucianne; Howe, A. R.; Nayar, R.; Turner, E. L.; Scargle, J.; Meadows, V.; Zee, A.

    2014-01-01

    Kepler's high cadence and incredible precision has provided an unprecedented view into stars and their planetary companions, revealing both expected and novel phenomena and systems. Due to the large number of Kepler lightcurves, the discovery of novel phenomena in particular has often been serendipitous in the course of searching for known forms of variability (for example, the discovery of the doubly pulsating elliptical binary KOI-54, originally identified by the transiting planet search pipeline). In this talk, we discuss progress on mining the Kepler data through both supervised and unsupervised machine learning, intended to both systematically search the Kepler lightcurves for rare or anomalous variability, and to create a variability catalog for community use. Mining the dataset in this way also allows for a quantitative identification of anomalous variability, and so may also be used as a signal-agnostic form of optical SETI. As the Kepler data are exceptionally rich, they provide an interesting counterpoint to machine learning efforts typically performed on sparser and/or noisier survey data, and will inform similar characterization carried out on future survey datasets.

  1. Additive manufacturing of tunable lenses

    Science.gov (United States)

    Schlichting, Katja; Novak, Tobias; Heinrich, Andreas

    2017-02-01

    Individual additive manufacturing of optical systems based on 3D Printing offers varied possibilities in design and usage. In addition to the additive manufacturing procedure, the usage of tunable lenses allows further advantages for intelligent optical systems. Our goal is to bring the advantages of additive manufacturing together with the huge potential of tunable lenses. We produced tunable lenses as a bundle without any further processing steps, like polishing. The lenses were designed and directly printed with a 3D Printer as a package. The design contains the membrane as an optical part as well as the mechanical parts of the lens, like the attachments for the sleeves which contain the oil. The dynamic optical lenses were filled with an oil. The focal length of the lenses changes due to a change of the radius of curvature. This change is caused by changing the pressure in the inside of the lens. In addition to that, we designed lenses with special structures to obtain different areas with an individual optical power. We want to discuss the huge potential of this technology for several applications. Further, an appropriate controlling system is needed. Wéll show the possibilities to control and regulate the optical power of the lenses. The lenses could be used for illumination tasks, and in the future, for individual measurement tasks. The main advantage is the individuality and the possibility to create an individual design which completely fulfills the requirements for any specific application.

  2. Kepler Asteroseismology of Red-giant Stars

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J.

    2012-01-01

    The Kepler mission, launched in March 2009, has revolutionized asteroseismology, providing detailed observations of thousands of stars. This has allowed in-depth analyses of stars ranging from compact hot subdwarfs to red giants, and including the detection of solar-like oscillations in hundreds...... of stars on or near the main sequence. Here I mainly consider solar-like oscillations in red giants, where Kepler observations are yielding results of a perhaps unexpected richness. In addition to giving a brief overview of the observational and numerical results for these stars, I present a simple...

  3. The solution of the generalized Kepler's equation

    Science.gov (United States)

    López, Rosario; Hautesserres, Denis; San-Juan, Juan Félix

    2018-01-01

    In the context of general perturbation theories, the main problem of the artificial satellite analyses the motion of an orbiter around an Earth-like planet, only perturbed by its equatorial bulge or J2 effect. By means of a Lie transform and the Krylov-Bogoliubov-Mitropolsky method, a first-order theory in closed form of the eccentricity is produced. During the evaluation of the theory, it is necessary to solve a generalization of the classical Kepler's equation. In this work, the application of a numerical technique and three initial guesses to the generalized Kepler's equation are discussed.

  4. Kepler and the Long Period Variables

    Directory of Open Access Journals (Sweden)

    Hartig E.

    2015-01-01

    Full Text Available High precision Kepler photometry is used to explore the details of AGB light curves. Since AGB variability has a typical time scale on order of a year we present methods for the removal of long term trends and quarterly changes in Kepler data. While undergoing long period variations of many magnitudes, the light curves are shown to be smooth at the millimagnitude level over much shorter time intervals. No flares or other rapid events were detected down to the sub-day time scale.

  5. RHIC electron lenses upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Binello, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Costanzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Pikin, A. I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Shrey, T. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tan, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  6. Planet Hunters: Kepler by Eye

    Science.gov (United States)

    Schwamb, Megan E.; Lintott, C.; Fischer, D.; Smith, A. M.; Boyajian, T. S.; Brewer, J. M.; Giguere, M. J.; Lynn, S.; Parrish, M.; Schawinski, K.; Schmitt, J.; Simpson, R.; Wang, J.

    2014-01-01

    Planet Hunters (http://www.planethunters.org), part of the Zooniverse's (http://www.zooniverse.org) collection of online citizen science projects, uses the World Wide Web to enlist the general public to identify transits in the pubic Kepler light curves. Planet Hunters utilizes human pattern recognition to identify planet transits that may be missed by automated detection algorithms looking for periodic events. Referred to as ‘crowdsourcing’ or ‘citizen science’, the combined assessment of many non-expert human classifiers with minimal training can often equal or best that of a trained expert and in many cases outperform the best machine-learning algorithm. Visitors to the Planet Hunters' website are presented with a randomly selected ~30-day light curve segment from one of Kepler’s ~160,000 target stars and are asked to draw boxes to mark the locations of visible transits in the web interface. 5-10 classifiers review each 30-day light curve segment. Since December 2010, more than 260,000 volunteers world wide have participated, contributing over 20 million classifications. We have demonstrated the success of a citizen science approach with the project’s more than 20 planet candidates, the discovery of PH1b, a transiting circumbinary planet in a quadruple star system, and the discovery of PH2-b, a confirmed Jupiter-sized planet in the habitable zone of a Sun-like star. I will provide an overview of Planet Hunters, highlighting several of project's most recent exoplanet and astrophysical discoveries. Acknowledgements: MES was supported in part by a NSF AAPF under award AST-1003258 and a American Philosophical Society Franklin Grant. We acknowledge support from NASA ADAP12-0172 grant to PI Fischer.

  7. Magnetic electron lenses

    CERN Document Server

    1982-01-01

    No single volume has been entirely devoted to the properties of magnetic lenses, so far as I am aware, although of course all the numerous textbooks on electron optics devote space to them. The absence of such a volume, bringing together in­ formation about the theory and practical design of these lenses, is surprising, for their introduction some fifty years ago has created an entirely new family of commercial instruments, ranging from the now traditional transmission electron microscope, through the reflection and transmission scanning microscopes, to co­ lumns for micromachining and microlithography, not to mention the host of experi­ mental devices not available commercially. It therefore seemed useful to prepare an account of the various aspects of mag­ netic lens studies. These divide naturally into the five chapters of this book: the theoretical background, in which the optical behaviour is described and formu­ lae given for the various aberration coefficients; numerical methods for calculat­ ing...

  8. Halo-lensing or Self-lensing? Locating the MACHO Lenses

    Science.gov (United States)

    Nelson, C. A.; Cook, K. H.; Popowski, P.; Drake, A. J.; Marshall, S. L.; Griest, K.; Vandehei, T.; Alcock, C.; Allsman, R. A.; Axelrod, T. S.; Freeman, K. C.; Peterson, B. A.; Alves, D. R.; Becker, A. C.; Stubbs, C. W.; Tomaney, A. B.; Bennett, D. P.; Geha, M.; Lehner, M. J.; Minniti, D.; Pratt, M. R.; Quinn, P. J.; Sutherland, W.; Welch, D.; MACHO Collaboration

    2000-12-01

    There are two principle geometrical arrangements which may explain Large Magellanic Cloud (LMC) microlensing: a) halo-lensing, in which the lensed object is part of the Milky Way galactic halo and b) self-lensing, in which the lensed object is part of the LMC. Self-lensing in turn may be broken into two categories: LMC-LMC self-lensing, in which both the source and the lens reside in the LMC and background self-lensing, in which the lens is a star in the LMC and the source star is drawn from some population behind the LMC. Models suggest the contribution of LMC-LMC self-lensing is small, so the nature of LMC microlensing may be estimated from the location of the microlensing source stars. If the source stars are in the LMC then microlensing is dominated by halo-lensing; conversely if the source stars are located behind the LMC then microlensing is dominated by self-lensing. Since background populations reside behind the LMC, we expect them to be both redder and fainter then the average population of the LMC. We attempt to determine if the MACHO source stars come from such a background population by comparing the HST color-magnitude diagram (CMD) of source stars to the CMD of the average population of the LMC and looking for the effects of extra reddening and extinction. The microlensing source stars are identified by deriving accurate centroids in the ground-based MACHO images using difference image analysis (DIA) and then transforming the DIA coordinates to the HST frame. Preliminary results suggest that halo-lensing accounts for ≳ 40% of the observed microlensing results. Support provided by NASA, DOE, NSF and NPSC.

  9. Gravitational lenses and cosmological evolution

    International Nuclear Information System (INIS)

    Peacock, J.A.

    1982-01-01

    The effect of gravitational lensing on the apparent cosmological evolution of extragalactic radio sources is investigated. Models for a lens population consisting of galaxies and clusters of galaxies are constructed and used to calculate the distribution of amplification factors caused by lensing. Although many objects at high redshifts are predicted to have flux densities altered by 10 to 20 per cent relative to a homogeneous universe, flux conservation implies that de-amplification is as common as amplification. The effects on cosmological evolution as inferred from source counts and redshift data are thus relatively small; the slope of the counts is not large enough for intrinsically rare lensing events of high amplitude to corrupt observed samples. Lensing effects may be of greater importance for optically selected quasars, where lenses of mass as low as approximately 10 -4 solar mass can cause large amplifications. (author)

  10. Gravitational lenses and. cosmological evolution

    Science.gov (United States)

    Peacock, J. A.

    1982-06-01

    The effect of gravitational lensing on the apparent evolution of extragalactic radio sources is investigated. Models for a lens population consisting of galaxies and clusters of galaxies are constructed used to calculate the distribution of amplification factors caused by lensing ,. Although many objects at high redshifts are predicted to have flux densities altered by 10-20 per cent relative to a homogeneous universe, flux conservation implies that de-amplification is as common as amplification. The effect on cosmological evolution as inferred from source counts and redshift data are thus relatively small; the slope of the counts is not large enough for intrinsically rare lensing events of high amplitude to corrupt observed sample Lensing effects may be of greater importance for optically selected quasar where lenses of mass as low as ˜10-4 Msun can cause large amplifications.

  11. KEPLER-1647B: THE LARGEST AND LONGEST-PERIOD KEPLER TRANSITING CIRCUMBINARY PLANET

    Energy Technology Data Exchange (ETDEWEB)

    Kostov, Veselin B. [NASA Goddard Space Flight Center, Mail Code 665, Greenbelt, MD 20771 (United States); Orosz, Jerome A.; Welsh, William F.; Short, Donald R. [Department of Astronomy, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States); Doyle, Laurance R. [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Principia College, IMoP, One Maybeck Place, Elsah, IL 62028 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Haghighipour, Nader [Institute for Astronomy, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Quarles, Billy [Department of Physics and Physical Science, The University of Nebraska at Kearney, Kearney, NE 68849 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas as Austin, Austin, TX 78712-0259 (United States); Ford, Eric B. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 428A Davey Lab, University Park, PA 16802 (United States); Gregorio, Joao [Atalaia Group and Crow-Observatory, Portalegre (Portugal); Hinse, Tobias C. [Korea Astronomy and Space Science Institute (KASI), Advanced Astronomy and Space Science Division, Daejeon 305-348 (Korea, Republic of); Isaacson, Howard [Department of Astronomy, University of California Berkeley, 501 Campbell Hall, Berkeley, CA 94720 (United States); Jenkins, Jon M. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Jensen, Eric L. N. [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Kane, Stephen [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States); Kull, Ilya, E-mail: veselin.b.kostov@nasa.gov [Department of Astronomy and Astrophysics, Tel Aviv University, 69978 Tel Aviv (Israel); and others

    2016-08-10

    We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of known short-period planets orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has a very long orbital period (∼1100 days) and was at conjunction only twice during the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-1647b is not only the longest-period transiting CBP at the time of writing, but also one of the longest-period transiting planets. With a radius of 1.06 ± 0.01 R {sub Jup}, it is also the largest CBP to date. The planet produced three transits in the light curve of Kepler-1647 (one of them during an eclipse, creating a syzygy) and measurably perturbed the times of the stellar eclipses, allowing us to measure its mass, 1.52 ± 0.65 M {sub Jup}. The planet revolves around an 11-day period eclipsing binary consisting of two solar-mass stars on a slightly inclined, mildly eccentric ( e {sub bin} = 0.16), spin-synchronized orbit. Despite having an orbital period three times longer than Earth’s, Kepler-1647b is in the conservative habitable zone of the binary star throughout its orbit.

  12. KEPLER-1647B: THE LARGEST AND LONGEST-PERIOD KEPLER TRANSITING CIRCUMBINARY PLANET

    International Nuclear Information System (INIS)

    Kostov, Veselin B.; Orosz, Jerome A.; Welsh, William F.; Short, Donald R.; Doyle, Laurance R.; Fabrycky, Daniel C.; Haghighipour, Nader; Quarles, Billy; Cochran, William D.; Endl, Michael; Ford, Eric B.; Gregorio, Joao; Hinse, Tobias C.; Isaacson, Howard; Jenkins, Jon M.; Jensen, Eric L. N.; Kane, Stephen; Kull, Ilya

    2016-01-01

    We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of known short-period planets orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has a very long orbital period (∼1100 days) and was at conjunction only twice during the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-1647b is not only the longest-period transiting CBP at the time of writing, but also one of the longest-period transiting planets. With a radius of 1.06 ± 0.01 R Jup , it is also the largest CBP to date. The planet produced three transits in the light curve of Kepler-1647 (one of them during an eclipse, creating a syzygy) and measurably perturbed the times of the stellar eclipses, allowing us to measure its mass, 1.52 ± 0.65 M Jup . The planet revolves around an 11-day period eclipsing binary consisting of two solar-mass stars on a slightly inclined, mildly eccentric ( e bin = 0.16), spin-synchronized orbit. Despite having an orbital period three times longer than Earth’s, Kepler-1647b is in the conservative habitable zone of the binary star throughout its orbit.

  13. Equations Governing Kepler's Laws of Planetary Motion

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Equations Governing Kepler's Laws of Planetary Motion. Renuka Ravindran. General Article Volume 14 Issue 12 December 2009 pp 1166-1170. Fulltext. Click here to view fulltext PDF. Permanent link:

  14. Johannes Kepler and the Rudolphine Tables

    Indian Academy of Sciences (India)

    Admin

    science in which planetary predictions typically erred by several degrees on the sky; the legacy of the Rudolphine Tables was a prediction scheme nearly 50 times more accurate. For Kepler these tables were the proof of the pudding, the substantiation of his laws of planetary motion. He called them “my chief astronomical ...

  15. Johannes Kepler and the Rudolphine Tables

    Indian Academy of Sciences (India)

    Admin

    He had neglected to show Tycho's heirs the title page before it was printed, and they objected to wording implying that he had to correct his mentor's data. The second printing (left) was hastily prepared at Prague, but Kepler found the typography so bad he had the third one (right) printed at Ulm, presumably at his expense.

  16. Exoplanet Population Distribution from Kepler Data

    Science.gov (United States)

    Traub, Wesley A.

    2015-08-01

    The underlying population of exoplanets around stars in the Kepler sample can be inferred by binning the Kepler planets in radius and period, invoking an empirical noise model, assuming a model exoplanet distribution function, randomly assigning planets to each of the Kepler target stars, asking whether each planet’s transit signal could be detected by Kepler, binning the resulting simulated detections, comparing the simulations with the observed data sample, and iterating on the model parameters until a satisfactory fit is obtained. The process is designed to simulate Kepler’s observing procedure. The key assumption is that the distribution function is continuous and the product of separable functions of period and radius. Any additional suspected biases in the sample can be handled by adjusting the noise model. The first advantage of this overall procedure is that the actual detection process is simulated as closely as possible, on a target by target basis, so the resulting estimated population should be closer to the actual population than by any other method of analysis. The second advantage is that the resulting distribution function can be extended to values of period and radius that go beyond the sample space, including, for example, application to estimating eta-sub-Earth, and also estimating the expected science yields of future direct-imaging exoplanet missions such as WFIRST-AFTA.

  17. Constraining the oblateness of Kepler planets

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wei [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Huang, Chelsea X. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Zhou, George [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Lin, D. N. C., E-mail: weizhu@astronomy.ohio-state.edu [UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2014-11-20

    We use Kepler short-cadence light curves to constrain the oblateness of planet candidates in the Kepler sample. The transits of rapidly rotating planets that are deformed in shape will lead to distortions in the ingress and egress of their light curves. We report the first tentative detection of an oblate planet outside the solar system, measuring an oblateness of 0.22{sub −0.11}{sup +0.11} for the 18 M{sub J} mass brown dwarf Kepler 39b (KOI 423.01). We also provide constraints on the oblateness of the planets (candidates) HAT-P-7b, KOI 686.01, and KOI 197.01 to be <0.067, <0.251, and <0.186, respectively. Using the Q' values from Jupiter and Saturn, we expect tidal synchronization for the spins of HAT-P-7b, KOI 686.01, and KOI 197.01, and for their rotational oblateness signatures to be undetectable in the current data. The potentially large oblateness of KOI 423.01 (Kepler 39b) suggests that the Q' value of the brown dwarf needs to be two orders of magnitude larger than that of the solar system gas giants to avoid being tidally spun down.

  18. Subaru Weak Lensing Measurements of Four Strong Lensing Clusters: Are Lensing Clusters Over-Concentrated?

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, Masamune; Hennawi, Joseph F.; Gladders, Michael D.; Dahle, Haakon; Natarajan, Priyamvada; Dalal, Neal; Koester, Benjamin P.; Sharon, Keren; Bayliss, Matthew

    2009-01-29

    We derive radial mass profiles of four strong lensing selected clusters which show prominent giant arcs (Abell 1703, SDSS J1446+3032, SDSS J1531+3414, and SDSS J2111-0115), by combining detailed strong lens modeling with weak lensing shear measured from deep Subaru Suprime-cam images. Weak lensing signals are detected at high significance for all four clusters, whose redshifts range from z = 0.28 to 0.64. We demonstrate that adding strong lensing information with known arc redshifts significantly improves constraints on the mass density profile, compared to those obtained from weak lensing alone. While the mass profiles are well fitted by the universal form predicted in N-body simulations of the {Lambda}-dominated cold dark matter model, all four clusters appear to be slightly more centrally concentrated (the concentration parameters c{sub vir} {approx} 8) than theoretical predictions, even after accounting for the bias toward higher concentrations inherent in lensing selected samples. Our results are consistent with previous studies which similarly detected a concentration excess, and increases the total number of clusters studied with the combined strong and weak lensing technique to ten. Combining our sample with previous work, we find that clusters with larger Einstein radii are more anomalously concentrated. We also present a detailed model of the lensing cluster Abell 1703 with constraints from multiple image families, and find the dark matter inner density profile to be cuspy with the slope consistent with -1, in agreement with expectations.

  19. Kepler AutoRegressive Planet Search

    Science.gov (United States)

    Caceres, Gabriel Antonio; Feigelson, Eric

    2016-01-01

    The Kepler AutoRegressive Planet Search (KARPS) project uses statistical methodology associated with autoregressive (AR) processes to model Kepler lightcurves in order to improve exoplanet transit detection in systems with high stellar variability. We also introduce a planet-search algorithm to detect transits in time-series residuals after application of the AR models. One of the main obstacles in detecting faint planetary transits is the intrinsic stellar variability of the host star. The variability displayed by many stars may have autoregressive properties, wherein later flux values are correlated with previous ones in some manner. Our analysis procedure consisting of three steps: pre-processing of the data to remove discontinuities, gaps and outliers; AR-type model selection and fitting; and transit signal search of the residuals using a new Transit Comb Filter (TCF) that replaces traditional box-finding algorithms. The analysis procedures of the project are applied to a portion of the publicly available Kepler light curve data for the full 4-year mission duration. Tests of the methods have been made on a subset of Kepler Objects of Interest (KOI) systems, classified both as planetary `candidates' and `false positives' by the Kepler Team, as well as a random sample of unclassified systems. We find that the ARMA-type modeling successfully reduces the stellar variability, by a factor of 10 or more in active stars and by smaller factors in more quiescent stars. A typical quiescent Kepler star has an interquartile range (IQR) of ~10 e-/sec, which may improve slightly after modeling, while those with IQR ranging from 20 to 50 e-/sec, have improvements from 20% up to 70%. High activity stars (IQR exceeding 100) markedly improve. A periodogram based on the TCF is constructed to concentrate the signal of these periodic spikes. When a periodic transit is found, the model is displayed on a standard period-folded averaged light curve. Our findings to date on real

  20. Hydrodynamic Simulations of Kepler's Supernova Remnant

    Science.gov (United States)

    Sullivan, Jessica; Blondin, John; Borkowski, Kazik; Reynolds, Stephen

    2018-01-01

    Kepler’s supernova remnant contains unusual features that strongly suggest an origin in a single-degenerate Type Ia explosion, including anisotropic circumstellar medium (CSM), a strong brightness gradient, and spatially varying expansion proper motions. We present 3Dhydrodynamic simulations to test a picture in which Kepler's progenitor binary emitted a strong asymmetric wind, densest in the orbital plane, while the system moved at high velocity through the ISM. We simulate the creation of the presupernova environment as well as the supernova blast wave, using the VH-1 grid-based hydrodynamics code. We first modeled an anisotropic wind to create an asymmetric bowshock around the progenitor, then the blast wave from thesupernova. The final simulation places both previous model pieces onto a single grid and allows the blast wave to expand into the bowshock. Models were completed on a Yin-Yang grids with matching angular resolutions. By manipulating parameters that control the asymmetry of the system, we attempted to find conditions that recreated the current state of Kepler. We analyzed these models by comparing images of Kepler from the Chandra X-ray Observatory to line-of-sight projections from the model results. We also present comparisons of simulated expansion velocities with recent observations of X-ray proper motions from Chandra images. We were able to produce models that contained similar features to those seen in Kepler. We find the greatest resemblance to Kepler images with a presupernova wind with an equator-to-pole density contrast of 3 and a moderately disk-like CSM at a 5° angle between equatorial plane and system motion.

  1. Likely transiting exocomets detected by Kepler

    Science.gov (United States)

    Rappaport, S.; Vanderburg, A.; Jacobs, T.; LaCourse, D.; Jenkins, J.; Kraus, A.; Rizzuto, A.; Latham, D. W.; Bieryla, A.; Lazarevic, M.; Schmitt, A.

    2018-02-01

    We present the first good evidence for exocomet transits of a host star in continuum light in data from the Kepler mission. The Kepler star in question, KIC 3542116, is of spectral type F2V and is quite bright at Kp = 10. The transits have a distinct asymmetric shape with a steeper ingress and slower egress that can be ascribed to objects with a trailing dust tail passing over the stellar disc. There are three deeper transits with depths of ≃ 0.1 per cent that last for about a day, and three that are several times more shallow and of shorter duration. The transits were found via an exhaustive visual search of the entire Kepler photometric data set, which we describe in some detail. We review the methods we use to validate the Kepler data showing the comet transits, and rule out instrumental artefacts as sources of the signals. We fit the transits with a simple dust-tail model, and find that a transverse comet speed of ˜35-50 km s-1 and a minimum amount of dust present in the tail of ˜1016 g are required to explain the larger transits. For a dust replenishment time of ˜10 d, and a comet lifetime of only ˜300 d, this implies a total cometary mass of ≳3 × 1017 g, or about the mass of Halley's comet. We also discuss the number of comets and orbital geometry that would be necessary to explain the six transits detected over the 4 yr of Kepler prime-field observations. Finally, we also report the discovery of a single comet-shaped transit in KIC 11084727 with very similar transit and host-star properties.

  2. Transiting Planets from Kepler, K2 & TESS

    Science.gov (United States)

    Lissauer, Jack

    2018-01-01

    NASA's Kepler spacecraft, launched in 2009, has been a resounding success. More than 4000 planet candidates have been identified using data from Kepler primary mission, which ended in 2013, and greater than 2000 of these candidates have been verified as bona fide exoplanets. After the loss of two reaction wheels ended the primary mission, the Kepler spacecraft was repurposed in 2014 to observe many fields on the sky for short periods. This new mission, dubbed K2, has led to the discovery of greater than 600 planet candidates, approximately 200 of which have been verified to date; most of these exoplanets are closer to us than the majority of exoplanets discovered by the primary Kepler mission. TESS, launching in 2018, will survey most of the sky for exoplanets, with emphasis on those orbiting nearby and/or bright host stars, making these planets especially well-suited for follow-up observations with other observatories to characterize atmospheric compositions and other properties. More than one-third of the planet candidates found by NASA's are associated with target stars that have more than one planet candidate, and such 'multis' account for the majority of candidates that have been verified as true planets. The large number of multis tells us that flat multiplanet systems like our Solar System are common. Virtually all of the candidate planetary systems are stable, as tested by numerical integrations that assume a physically motivated mass-radius relationship. Statistical studies performed on these candidate systems reveal a great deal about the architecture of planetary systems, including the typical spacing of orbits and flatness. The characteristics of several of the most interesting confirmed Kepler & K2 multi-planet systems will also be discussed.

  3. Pulsar lensing geometry

    Science.gov (United States)

    Liu, Siqi; Pen, Ue-Li; Macquart, J.-P.; Brisken, Walter; Deller, Adam

    2016-05-01

    We test the inclined sheet pulsar scintillation model (Pen & Levin) against archival very long baseline interferometry (VLBI) data on PSR 0834+06 and show that its scintillation properties can be precisely reproduced by a model in which refraction occurs on two distinct lens planes. These data strongly favour a model in which grazing-incidence refraction instead of diffraction off turbulent structures is the primary source of pulsar scattering. This model can reproduce the parameters of the observed diffractive scintillation with an accuracy at the percent level. Comparison with new VLBI proper motion results in a direct measure of the ionized interstellar medium (ISM) screen transverse velocity. The results are consistent with ISM velocities local to the PSR 0834+06 sight-line (through the Galaxy). The simple 1-D structure of the lenses opens up the possibility of using interstellar lenses as precision probes for pulsar lens mapping, precision transverse motions in the ISM, and new opportunities for removing scattering to improve pulsar timing. We describe the parameters and observables of this double screen system. While relative screen distances can in principle be accurately determined, a global conformal distance degeneracy exists that allows a rescaling of the absolute distance scale. For PSR B0834+06, we present VLBI astrometry results that provide (for the first time) a direct measurement of the distance of the pulsar. For most of the recycled millisecond pulsars that are the targets of precision timing observations, the targets where independent distance measurements are not available. The degeneracy presented in the lens modelling could be broken if the pulsar resides in a binary system.

  4. THE ATMOSPHERES OF THE HOT-JUPITERS KEPLER-5b AND KEPLER-6b OBSERVED DURING OCCULTATIONS WITH WARM-SPITZER AND KEPLER

    Energy Technology Data Exchange (ETDEWEB)

    Desert, Jean-Michel; Charbonneau, David; Fressin, Francois; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Madhusudhan, Nikku [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Knutson, Heather A. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Deming, Drake [Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Brown, Timothy M. [Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States); Caldwell, Douglas [SETI Institute, Mountain View, CA 94043 (United States); Ford, Eric B. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Gilliland, Ronald L. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Marcy, Geoffrey W. [Berkeley Astronomy Department, University of California, Berkeley, CA 94720 (United States); Seager, Sara, E-mail: jdesert@cfa.harvard.edu [Massachusetts Institute of Technology, Cambridge, MA 02159 (United States)

    2011-11-01

    This paper reports the detection and the measurements of occultations of the two transiting hot giant exoplanets Kepler-5b and Kepler-6b by their parent stars. The observations are obtained in the near-infrared with Warm-Spitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of constraining the eccentricities of these systems and of obtaining broadband emergent photometric data for individual planets. For both targets, the occultations are detected at the 3{sigma} level at each wavelength with mid-occultation times consistent with circular orbits. The brightness temperatures of these planets are deduced from the infrared observations and reach T{sub Spitzer} = 1930 {+-} 100 K and T{sub Spitzer} = 1660 {+-} 120 K for Kepler-5b and Kepler-6b, respectively. We measure optical geometric albedos A{sub g} in the Kepler bandpass and find A{sub g} = 0.12 {+-} 0.04 for Kepler-5b and A{sub g} = 0.11 {+-} 0.04 for Kepler-6b, leading to upper an limit for the Bond albedo of A{sub B} {<=} 0.17 in both cases. The observations for both planets are best described by models for which most of the incident energy is redistributed on the dayside, with only less than 10% of the absorbed stellar flux redistributed to the nightside of these planets.

  5. The Kepler Science Data Processing Pipeline Source Code Road Map

    Science.gov (United States)

    Wohler, Bill; Jenkins, Jon M.; Twicken, Joseph D.; Bryson, Stephen T.; Clarke, Bruce Donald; Middour, Christopher K.; Quintana, Elisa Victoria; Sanderfer, Jesse Thomas; Uddin, Akm Kamal; Sabale, Anima; hide

    2016-01-01

    We give an overview of the operational concepts and architecture of the Kepler Science Processing Pipeline. Designed, developed, operated, and maintained by the Kepler Science Operations Center (SOC) at NASA Ames Research Center, the Science Processing Pipeline is a central element of the Kepler Ground Data System. The SOC consists of an office at Ames Research Center, software development and operations departments, and a data center which hosts the computers required to perform data analysis. The SOC's charter is to analyze stellar photometric data from the Kepler spacecraft and report results to the Kepler Science Office for further analysis. We describe how this is accomplished via the Kepler Science Processing Pipeline, including, the software algorithms. We present the high-performance, parallel computing software modules of the pipeline that perform transit photometry, pixel-level calibration, systematic error correction, attitude determination, stellar target management, and instrument characterization.

  6. Photometer Performance Assessment in Kepler Science Data Processing

    Science.gov (United States)

    Li, Jie; Allen, Christopher; Bryson, Stephen T.; Caldwell, Douglas A.; Chandrasekaran, Hema; Clarke, Bruce D.; Gunter, Jay P.; Jenkins, Jon M.; Klaus, Todd C.; Quintana, Elisa V.; hide

    2010-01-01

    This paper describes the algorithms of the Photometer Performance Assessment (PPA) software component in the science data processing pipeline of the Kepler mission. The PPA performs two tasks: One is to analyze the health and performance of the Kepler photometer based on the long cadence science data down-linked via Ka band approximately every 30 days. The second is to determine the attitude of the Kepler spacecraft with high precision at each long cadence. The PPA component is demonstrated to work effectively with the Kepler flight data.

  7. First Kepler Results on RR Lyrae Stars

    DEFF Research Database (Denmark)

    Kolenberg, K.; Szabó, R.; Kurtz, D. W.

    2010-01-01

    We present the first results of our analyses of selected RR Lyrae stars for which data have been obtained by the Kepler Mission. As expected, we find a significant fraction of the RRab stars to show the Blazhko effect, a still unexplained phenomenon that manifests itself as periodic amplitude...... and phase modulations of the light curve, on timescales of typically tens to hundreds of days. The long time span of the Kepler Mission of 3.5 yr and the unprecedentedly high precision of its data provide a unique opportunity for the study of RR Lyrae stars. Using data of a modulated star observed...... in the first roll as a showcase, we discuss the data, our analyses, findings, and their implications for our understanding of RR Lyrae stars and the Blazhko effect. With at least 40% of the RR Lyrae stars in our sample showing modulation, we confirm the high incidence rate that was only found in recent high...

  8. Exosat observations of the Kepler supernova remnant

    International Nuclear Information System (INIS)

    Smith, A.; Peacock, A.; Arnaud, M.; Ballet, J.; Rothenflug, R.

    1989-01-01

    The medium-energy experiment on board Exosat was used to measure the X-ray spectrum of the Kepler supernova remnant over the range 1.5-10 keV. An Fe emission line was clearly resolved with an energy of about 6.5 keV and equivalent width of about 1.8 keV. This was superposed on a continuum with a temperature of 5.0(+3.8, -1.9) keV. The medium-energy spectrum is shown to be consistent with a model in which the Kepler SNR is presently in a Sedov phase of evolution, the 5 keV continuum arises from the shocked interstellar/circumstellar medium, and thermal (but not ionization) equilibrium exists between electrons and ions behind the primary shock front. However, in this case, an overabundance of iron by more than 6 times cosmic is required. 28 refs

  9. Spectroscopic follow up of Kepler planet candidates

    DEFF Research Database (Denmark)

    Latham..[], D. W.; Cochran, W. D.; Marcy, G.W.

    2010-01-01

    and not planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using......Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from...... spectroscopic orbits. The most precious resource for this work is HIRES on Keck I, to be joined by HARPS-North on the William Herschel Telescope when that new spectrometer comes on line in two years. Because a large fraction of the planet candidates are in fact stellar systems involving eclipsing stars...

  10. Spectroscopic follow up of Kepler planet candidates

    DEFF Research Database (Denmark)

    Latham..[], D. W.; Cochran, W. D.; Marcy, G.W.

    2010-01-01

    Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from...... spectroscopic orbits. The most precious resource for this work is HIRES on Keck I, to be joined by HARPS-North on the William Herschel Telescope when that new spectrometer comes on line in two years. Because a large fraction of the planet candidates are in fact stellar systems involving eclipsing stars...... and not planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using...

  11. Automatic Classification of Kepler Planetary Transit Candidates

    OpenAIRE

    McCauliff, Sean D.; Jenkins, Jon M.; Catanzarite, Joseph; Burke, Christopher J.; Coughlin, Jeffrey L.; Twicken, Joseph D.; Tenenbaum, Peter; Seader, Shawn; Li, Jie; Cote, Miles

    2014-01-01

    In the first three years of operation the Kepler mission found 3,697 planet candidates from a set of 18,406 transit-like features detected on over 200,000 distinct stars. Vetting candidate signals manually by inspecting light curves and other diagnostic information is a labor intensive effort. Additionally, this classification methodology does not yield any information about the quality of planet candidates; all candidates are as credible as any other candidate. The torrent of exoplanet disco...

  12. Modelling secondary eclipses of Kepler exoplanets

    Directory of Open Access Journals (Sweden)

    Hambálek Lubomír

    2015-01-01

    Full Text Available We have selected several Kepler objects with potentially the deepest secondary eclipses. By combination of many single phased light-curves (LCs we have produced a smooth LC with a larger SNR and made the secondary eclipses more distinct. This allowed us to measure the depth of primary and secondary minimum with greater accuracy and then to determine stellar and planetary radii by simplex modelling.

  13. Johannes Kepler - And the New Astronomy

    Science.gov (United States)

    Voelkel, James R.

    1999-11-01

    Johannes Kepler (1571-1630) is remembered as one of the greatest medieval astronomers in the tradition of Copernicus and Galileo, a man who made major contributions to physics, astronomy, and mathematics. Born in Germany and trained as a theologian, Kepler did not hesitate to challenge church doctrine by supporting the iconoclastic theory of a Sun-centered solar system. As Imperial Mathematician to the Holy Roman Emperor, he conducted careful observations of the night sky, which led to his discovery of the three Laws of Planetary Motion and the orbit of Mars. He also devised the Rudolphine Tables on planetary movements, and made key improvements to the telescope. Voelkel vividly describes the scientific achievements, providing enough background in physics and trigonometry so even beginners can enjoy this book. The author also gives us a captivating account of Kepler's tumultuous life, plagued by misery, disease, and fervent religious prosecution by the Catholic Church.Oxford Portraits in Science is an ongoing series of scientific biographies for young adults. Written by top scholars and writers, each biography examines the personality of its subject as well as the thought process leading to his or her discoveries. These illustrated biographies combine accessible technical information with compelling personal stories to portray the scientists whose work has shaped our understanding of the natural world.

  14. Automatic Classification of Kepler Planetary Transit Candidates

    Science.gov (United States)

    McCauliff, Sean D.; Jenkins, Jon M.; Catanzarite, Joseph; Burke, Christopher J.; Coughlin, Jeffrey L.; Twicken, Joseph D.; Tenenbaum, Peter; Seader, Shawn; Li, Jie; Cote, Miles

    2015-06-01

    In the first three years of operation, the Kepler mission found 3697 planet candidates (PCs) from a set of 18,406 transit-like features detected on more than 200,000 distinct stars. Vetting candidate signals manually by inspecting light curves and other diagnostic information is a labor intensive effort. Additionally, this classification methodology does not yield any information about the quality of PCs; all candidates are as credible as any other. The torrent of exoplanet discoveries will continue after Kepler, because a number of exoplanet surveys will have an even broader search area. This paper presents the application of machine-learning techniques to the classification of the exoplanet transit-like signals present in the Kepler light curve data. Transit-like detections are transformed into a uniform set of real-numbered attributes, the most important of which are described in this paper. Each of the known transit-like detections is assigned a class of PC; astrophysical false positive; or systematic, instrumental noise. We use a random forest algorithm to learn the mapping from attributes to classes on this training set. The random forest algorithm has been used previously to classify variable stars; this is the first time it has been used for exoplanet classification. We are able to achieve an overall error rate of 5.85% and an error rate for classifying exoplanets candidates of 2.81%.

  15. Cosmology with weak lensing surveys

    International Nuclear Information System (INIS)

    Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan

    2008-01-01

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  16. Kepler: A Search for Terrestrial Planets. K2 Handbook

    Science.gov (United States)

    Van Cleve, Jeffrey; Bryson, Steve

    2017-01-01

    The Kepler spacecraft was repurposed for the K2 mission a year after the failure of the second of Kepler's four reaction wheels in 2013 May. The purpose of this document, the K2 Handbook (K2H), is to describe features of K2 operations, performance, data analysis, and archive products which are common to most K2 campaigns, but different in degree or kind from the corresponding features of the Kepler mission.The K2 Handbook is meant to be read with the following companion documents, which are all publicly available:1. Kepler Instrument Handbook (KSCI-19033) provides information about the design, performance and operational constraints of the instrument and an overview of the types of pixel data that are available.2. Kepler Data Processing Handbook (KSCI-19081) describes how pixels downloaded from the spacecraft are converted by the Kepler Data Processing Pipeline into the data products available at the MAST archive3. Kepler Archive Manual (KDMC-100008) describes the format and content of the data products and how to search for them.4. Kepler Data Characteristics Handbook (KSCI-19040) describes recurring non-astrophysical features of the Kepler data due to instrument signatures, spacecraft events or solar activity and explains how these characteristics are handled by the Kepler pipeline.5. The Ecliptic Plane Input Catalog describes the provenance of the positions and Kepler magnitudes used for target management and aperature photometry.6. K2 Data Release Notes (DRN) are on-line documents available on the K2 science website which describe the data inventory, instrumental signatures and events peculiar to individual observing campaigns.

  17. The architecture and formation of the Kepler-30 planetary system

    Science.gov (United States)

    Panichi, F.; Goździewski, K.; Migaszewski, C.; Szuszkiewicz, E.

    2018-04-01

    We study the orbital architecture, physical characteristics of planets, formation and long-term evolution of the Kepler-30 planetary system, detected and announced in 2012 by the KEPLER team. We show that the Kepler-30 system belongs to a particular class of very compact and quasi-resonant, yet long-term stable planetary systems. We re-analyse the light curves of the host star spanning Q1-Q17 quarters of the KEPLER mission. A huge variability of the Transit Timing Variations (TTV) exceeding 2 days is induced by a massive Jovian planet located between two Neptune-like companions. The innermost pair is near to the 2:1 mean motion resonance (MMR), and the outermost pair is close to higher order MMRs, such as 17:7 and 7:3. Our re-analysis of photometric data allows us to constrain, better than before, the orbital elements, planets' radii and masses, which are 9.2 ± 0.1, 536 ± 5, and 23.7 ± 1.3 Earth masses for Kepler-30b, Kepler-30c and Kepler-30d, respectively. The masses of the inner planets are determined within ˜1% uncertainty. We infer the internal structures of the Kepler-30 planets and their bulk densities in a wide range from (0.19 ± 0.01) g.cm-3 for Kepler-30d, (0.96 ± 0.15) g.cm-3 for Kepler-30b, to (1.71 ± 0.13) g.cm-3 for the Jovian planet Kepler-30c. We attempt to explain the origin of this unique planetary system and a deviation of the orbits from exact MMRs through the planetary migration scenario. We anticipate that the Jupiter-like planet plays an important role in determining the present dynamical state of this system.

  18. Use of Scleral Lenses and Miniscleral Lenses After Penetrating Keratoplasty.

    Science.gov (United States)

    Barnett, Melissa; Lien, Vivian; Li, Jennifer Y; Durbin-Johnson, Blythe; Mannis, Mark J

    2016-05-01

    To examine the clinical outcomes of scleral lenses for visual rehabilitation after penetrating keratoplasty (PK). A retrospective review was conducted for 34 patients (48 eyes) who had a history of prior PK and were fit with scleral lenses between October 2009 and December 2013 at the UC Davis Eye Center. The most common initial indication for PK was keratoconus in 27 eyes (56%). Thirty-three eyes (69%) had previously been fit with other types of contact lenses, with small-diameter rigid gas-permeable lenses being the most common. The improvement in best-corrected visual acuity with a scleral lens compared with prior spectacle refraction or other contact lens was a mean of two best-corrected visual acuity lines. Forty-four eyes (91.7%) achieved functional vision with best scleral lens-corrected visual acuities of 20/40 or better. Patients who continued wearing scleral lenses were significantly more likely to report "good" subjective vision compared with patients who abandoned scleral lens wear (P=0.009), although change in objective best-corrected visual acuity did not differ significantly. There were no cases of infectious keratitis. Six eyes (12.5%) developed graft rejection; 3 were able to resume scleral lens wear. Nineteen eyes (39.5%) discontinued scleral lens wear for various reasons, the most common reason for discontinuation of lens wear was difficulty with scleral lens insertion or removal (8 eyes, 42.1%). Scleral lenses are effective and safe in patients who have had PK. There was a mean gain in visual acuity, with the majority of patients achieving 20/40 vision or better. The patient's subjective perception of vision was a significant factor in determining whether scleral lens wear was continued or abandoned.

  19. Scleral lenses: a literature review.

    Science.gov (United States)

    Schornack, Muriel M

    2015-01-01

    To present a comprehensive review of current and historical literature on scleral lenses. A comprehensive search of several databases from each database's earliest inception to May 23, 2014 was conducted by an experienced librarian with input from the author to locate articles related to scleral lens design, fabrication, prescription, and management. A total of 899 references were identified, 184 of which were directly related to scleral lenses. References of interest were organized by date, topic, and study design. Most of articles published before 1983 presented lens design and fabrication techniques or indications for scleral lens therapy. Case reviews published after 1983 identified major indications for scleral lenses (corneal ectasia, ocular surface disease, and refractive error) and visual and functional outcomes of scleral lens wear. Statistically significant improvements in visual acuity, vision-related quality of life, and ocular surface integrity were reported. Reviews of ocular and systemic conditions suggested that comprehensive management strategies for these conditions could include scleral lenses. Early work investigating scleral lens fitting characteristics, optical qualities, and potential physiological impact on anterior ocular structures have been published in the past 5 years. Indications for scleral lens wear are well-established. Developing areas of research on the physiologic impact of scleral lens wear on the ocular surface, the use of technology to improve scleral lens vision and fit, and the impact of these devices on the quality of life should further enhance our understanding of scleral lenses in the future.

  20. The Kepler-10 planetary system revisited by HARPS-N

    DEFF Research Database (Denmark)

    Dumusque, Xavier; Bonomo, Aldo S.; Haywood, Raphaelle D.

    2014-01-01

    Kepler-10b was the first rocky planet detected by the Kepler satellite and confirmed with radial velocity follow-up observations from Keck-HIRES. The mass of the planet was measured with a precision of around 30%, which was insufficient to constrain models of its internal structure and compositio...

  1. The Scattering Outcomes of Kepler Circumbinary Planets: Planet Mass Ratio

    Science.gov (United States)

    Gong, Yan-Xiang; Ji, Jianghui

    2017-11-01

    Recent studies reveal that the free eccentricities of Kepler-34b and Kepler-413b are much larger than their forced eccentricities, implying that scattering events may take place in their formation. The observed orbital configuration of Kepler-34b cannot be well reproduced in disk-driven migration models, whereas a two-planet scattering scenario can play a significant role of shaping the planetary configuration. These studies indicate that circumbinary planets discovered by Kepler may have experienced scattering process. In this work, we extensively investigate the scattering outcomes of circumbinary planets focusing on the effects of planet mass ratio. We find that the planetary mass ratio and the the initial relative locations of planets act as two important parameters that affect the eccentricity distribution of the surviving planets. As an application of our model, we discuss the observed orbital configurations of Kepler-34b and Kepler-413b. We first adopt the results from the disk-driven models as the initial conditions, then simulate the scattering process that occurs in the late evolution stage of circumbinary planets. We show that the present orbital configurations of Kepler-34b and Kepler-413b can be well reproduced when considering a two unequal-mass planet ejection model. Our work further suggests that some of the currently discovered circumbinary single-planet systems may be survivors of original multiple-planet systems. The disk-driven migration and scattering events occurring in the late stage both play an irreplaceable role in sculpting the final systems.

  2. Kepler's cosmological synthesis astrology, mechanism and the soul

    CERN Document Server

    Boner, Patrick J

    2013-01-01

    Spanning the course of his career, this book brings new light to Kepler's vitalistic views and their central place in his world picture. It challenges our view of Kepler as a nascent mechanical philosopher who fell back on an older form of physics.

  3. 12000 rotation periods of Kepler stars (Nielsen+, 2013)

    DEFF Research Database (Denmark)

    Nielsen, M. B.; Gizon, L.; Schunker, H.

    2013-01-01

    Rotation periods of 12253 stars in the Kepler field. The periods are determined by the brightness variations, from star spots or active regions, in the light curves of the white light photometry obtained by the Kepler spacecraft. The median absolute deviation from the median (MAD) of the periods...

  4. The Scattering Outcomes of Kepler Circumbinary Planets: Planet Mass Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yan-Xiang; Ji, Jianghui, E-mail: yxgong@pmo.ac.cn, E-mail: jijh@pmo.ac.cn [CAS Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2017-11-01

    Recent studies reveal that the free eccentricities of Kepler-34b and Kepler-413b are much larger than their forced eccentricities, implying that scattering events may take place in their formation. The observed orbital configuration of Kepler-34b cannot be well reproduced in disk-driven migration models, whereas a two-planet scattering scenario can play a significant role of shaping the planetary configuration. These studies indicate that circumbinary planets discovered by Kepler may have experienced scattering process. In this work, we extensively investigate the scattering outcomes of circumbinary planets focusing on the effects of planet mass ratio . We find that the planetary mass ratio and the the initial relative locations of planets act as two important parameters that affect the eccentricity distribution of the surviving planets. As an application of our model, we discuss the observed orbital configurations of Kepler-34b and Kepler-413b. We first adopt the results from the disk-driven models as the initial conditions, then simulate the scattering process that occurs in the late evolution stage of circumbinary planets. We show that the present orbital configurations of Kepler-34b and Kepler-413b can be well reproduced when considering a two unequal-mass planet ejection model. Our work further suggests that some of the currently discovered circumbinary single-planet systems may be survivors of original multiple-planet systems. The disk-driven migration and scattering events occurring in the late stage both play an irreplaceable role in sculpting the final systems.

  5. Atmospheric parameters of 82 red giants in the Kepler field

    NARCIS (Netherlands)

    Thygesen, A.O.; Frandsen, S.; Bruntt, H.; Kallinger, T.; Andersen, M.F.; Elsworth, Y.P.; Hekker, S.; Karoff, C.; Stello, D.; Brogaard, K.; J. Burke, C.; Caldwell, D.A.; Christiansen, J.L.

    2012-01-01

    Context. Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims. We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82 red giants that are targets for the Kepler mission. Methods.

  6. Atmospheric parameters of 82 red giants in the Kepler field

    DEFF Research Database (Denmark)

    Overaa Thygesen, Anders; Frandsen, Søren; Bruntt, Hans

    2012-01-01

    Context. Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims. We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82 red giants that are targets for the Kepler mission. Methods...... elements were measured using equivalent widths of the spectral lines. Results. We identify discrepancies in log g and [Fe/H], compared to the parameters based on photometric indices in the Kepler Input Catalogue (larger than 2.0 dex for log g and [Fe/H] for individual stars). The Teff found from...... parameters and element abundances of 82 red giants. The large discrepancies between the spectroscopic log g and [Fe/H] and values in the Kepler Input Catalogue emphasize the need for further detailed spectroscopic follow-up of the Kepler targets in order to produce reliable results from the asteroseismic...

  7. Aspheric lenses for terahertz imaging.

    Science.gov (United States)

    Lo, Yat Hei; Leonhardt, Rainer

    2008-09-29

    We present novel designs for aspheric lenses used in terahertz (THz) imaging. As different surfaces result in different beam shaping properties and in different losses from reflection and absorption, the resultant imaging resolution (i.e. the focal spot size) depends critically on the design approach. We evaluate the different lens designs using Kirchhoff's scalar diffraction theory, and test the predictions experimentally. We also show that our lenses can achieve sub-wavelength resolution. While our lens designs are tested with THz radiation, the design considerations are applicable also to other regions of the electro-magnetic spectrum.

  8. Gravitational lensing by exotic objects

    Science.gov (United States)

    Asada, Hideki

    2017-11-01

    This paper reviews a phenomenological approach to the gravitational lensing by exotic objects such as the Ellis wormhole lens, where the exotic lens objects may follow a non-standard form of the equation of state or may obey a modified gravity theory. A gravitational lens model is proposed in the inverse powers of the distance, such that the Schwarzschild lens and exotic lenses can be described in a unified manner as a one parameter family. As observational implications, the magnification, shear, photo-centroid motion and time delay in this lens model are discussed.

  9. Calibrating gyrochronology using Kepler asteroseismic targets

    Science.gov (United States)

    Angus, Ruth; Aigrain, Suzanne; Foreman-Mackey, Daniel; McQuillan, Amy

    2015-06-01

    Among the available methods for dating stars, gyrochronology is a powerful one because it requires knowledge of only the star's mass and rotation period. Gyrochronology relations have previously been calibrated using young clusters, with the Sun providing the only age dependence, and are therefore poorly calibrated at late ages. We used rotation period measurements of 310 Kepler stars with asteroseismic ages, 50 stars from the Hyades and Coma Berenices clusters and 6 field stars (including the Sun) with precise age measurements to calibrate the gyrochronology relation, whilst fully accounting for measurement uncertainties in all observable quantities. We calibrated a relation of the form P = An × (B - V - c)b, where P is rotation period in days, A is age in Myr, B and V are magnitudes and a, b and n are the free parameters of our model. We found a = 0.40^{+0.3}_{-0.05}, b = 0.31^{+0.05}_{-0.02} and n = 0.55^{+0.02}_{-0.09}. Markov Chain Monte Carlo methods were used to explore the posterior probability distribution functions of the gyrochronology parameters and we carefully checked the effects of leaving out parts of our sample, leading us to find that no single relation between rotation period, colour and age can adequately describe all the subsets of our data. The Kepler asteroseismic stars, cluster stars and local field stars cannot all be described by the same gyrochronology relation. The Kepler asteroseismic stars may be subject to observational biases; however, the clusters show unexpected deviations from the predicted behaviour, providing concerns for the overall reliability of gyrochronology as a dating method.

  10. RADIAL VELOCITY MONITORING OF KEPLER HEARTBEAT STARS

    International Nuclear Information System (INIS)

    Shporer, Avi; Fuller, Jim; Isaacson, Howard; Hambleton, Kelly; Prša, Andrej; Thompson, Susan E.; Kurtz, Donald W.; Howard, Andrew W.; O’Leary, Ryan M.

    2016-01-01

    Heartbeat stars (HB stars) are a class of eccentric binary stars with close periastron passages. The characteristic photometric HB signal evident in their light curves is produced by a combination of tidal distortion, heating, and Doppler boosting near orbital periastron. Many HB stars continue to oscillate after periastron and along the entire orbit, indicative of the tidal excitation of oscillation modes within one or both stars. These systems are among the most eccentric binaries known, and they constitute astrophysical laboratories for the study of tidal effects. We have undertaken a radial velocity (RV) monitoring campaign of Kepler HB stars in order to measure their orbits. We present our first results here, including a sample of 22 Kepler HB systems, where for 19 of them we obtained the Keplerian orbit and for 3 other systems we did not detect a statistically significant RV variability. Results presented here are based on 218 spectra obtained with the Keck/HIRES spectrograph during the 2015 Kepler observing season, and they have allowed us to obtain the largest sample of HB stars with orbits measured using a single instrument, which roughly doubles the number of HB stars with an RV measured orbit. The 19 systems measured here have orbital periods from 7 to 90 days and eccentricities from 0.2 to 0.9. We show that HB stars draw the upper envelope of the eccentricity–period distribution. Therefore, HB stars likely represent a population of stars currently undergoing high eccentricity migration via tidal orbital circularization, and they will allow for new tests of high eccentricity migration theories.

  11. The astronomical revolution Copernicus, Kepler, Borelli

    CERN Document Server

    Koyre, Alexandre

    2013-01-01

    Originally published in English in 1973. This volume traces the development of the revolution which so drastically altered man's view of the universe in the sixteenth and seventeenth centuries. The ""astronomical revolution"" was accomplished in three stages, each linked with the work of one man. With Copernicus, the sun became the centre of the universe. With Kepler, celestial dynamics replaced the kinematics of circles and spheres used by Copernicus. With Borelli the unification of celestial and terrestrial physics was completed by abandonment of the circle in favour the straight line to inf

  12. Gravitational Lensing of Supernova Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Mena, Olga; /Fermilab /Rome U.; Mocioiu, Irina; /Penn State U.; Quigg, Chris; /Fermilab

    2006-10-01

    The black hole at the center of the galaxy is a powerful lens for supernova neutrinos. In the very special circumstance of a supernova near the extended line of sight from Earth to the galactic center, lensing could dramatically enhance the neutrino flux at Earth and stretch the neutrino pulse.

  13. The Optical Gravitational Lensing Experiment

    Science.gov (United States)

    Udalski, A.; Szymanski, M.; Kaluzny, J.; Kubiak, M.; Mateo, Mario

    1992-01-01

    The technical features are described of the Optical Gravitational Lensing Experiment, which aims to detect a statistically significant number of microlensing events toward the Galactic bulge. Clusters of galaxies observed during the 1992 season are listed and discussed and the reduction methods are described. Future plans are addressed.

  14. Scientific visualization of gravitational lenses

    International Nuclear Information System (INIS)

    Magallon, M.

    1999-01-01

    Concepts related to gravitational lenses are discussed and applied to develop an interactive visualization tool that allow us to investigate them. Optimization strategies were performed to elaborate the tool. Some results obtained from the application of the tool are shown [es

  15. Optics Demonstrations Using Cylindrical Lenses

    Science.gov (United States)

    Ivanov, Dragia; Nikolov, Stefan

    2015-01-01

    In this paper we consider the main properties of cylindrical lenses and propose several demonstrational experiments that can be performed with them. Specifically we use simple glasses full of water to demonstrate some basic geometrical optics principles and phenomena. We also present some less standard experiments that can be performed with such…

  16. Polarization optics of GRIN lenses

    Science.gov (United States)

    Camacho, Javier; Tentori, Diana

    2001-01-01

    In this paper we show that the matrix representation for a linear retarder, given by Jones calculus, can be successfully applied to describe the birefringence properties of GRIN lenses for meridional rays. The usefulness of this description is experimentally verified by comparing the output pattern of a GRIN lens obtained in a linear polariscope with the predicted conoscopic pattern.

  17. Weak lensing and dark energy

    International Nuclear Information System (INIS)

    Huterer, Dragan

    2002-01-01

    We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy

  18. Weak lensing and cosmological investigation

    CERN Document Server

    Acquaviva, V

    2005-01-01

    In the last few years the scientific community has been dealing with the challenging issue of identifying the dark energy component. We regard weak gravitational lensing as a brand new, and extremely important, tool for cosmological investigation in this field. In fact, the features imprinted on the cosmic microwave background radiation by the lensing from the intervening distribution of matter represent a pretty unbiased estimator, and can thus be used for putting constraints on different dark energy models. This is true in particular for the magnetic-type B-modes of CMB polarization, whose unlensed spectrum at large multipoles (l approximately=1000) is very small even in presence of an amount of gravitational waves as large as currently allowed by the experiments: therefore, on these scales the lensing phenomenon is the only responsible for the observed power, and this signal turns out to be a faithful tracer of the dark energy dynamics. We first recall the formal apparatus of the weak lensing in extended t...

  19. Exploring exoplanet populations with NASA's Kepler Mission.

    Science.gov (United States)

    Batalha, Natalie M

    2014-09-02

    The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star type, and insolation flux. The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first 3 y of data, 100 planets of which are in the habitable zone. The catalog has a high reliability rate (85-90% averaged over the period/radius plane), which is improving as follow-up observations continue. Dynamical (e.g., velocimetry and transit timing) and statistical methods have confirmed and characterized hundreds of planets over a large range of sizes and compositions for both single- and multiple-star systems. Population studies suggest that planets abound in our galaxy and that small planets are particularly frequent. Here, I report on the progress Kepler has made measuring the prevalence of exoplanets orbiting within one astronomical unit of their host stars in support of the National Aeronautics and Space Administration's long-term goal of finding habitable environments beyond the solar system.

  20. EDITORIAL: Focus on Gravitational Lensing

    Science.gov (United States)

    Jain, Bhuvnesh

    2007-11-01

    Gravitational lensing emerged as an observational field following the 1979 discovery of a doubly imaged quasar lensed by a foreground galaxy. In the 1980s and '90s dozens of other multiply imaged systems were observed, as well as time delay measurements, weak and strong lensing by galaxies and galaxy clusters, and the discovery of microlensing in our galaxy. The rapid pace of advances has continued into the new century. Lensing is currently one of best techniques for finding and mapping dark matter over a wide range of scales, and also addresses broader cosmological questions such as understanding the nature of dark energy. This focus issue of New Journal of Physics presents a snapshot of current research in some of the exciting areas of lensing. It provides an occasion to look back at the advances of the last decade and ahead to the potential of the coming years. Just about a decade ago, microlensing was discovered through the magnification of stars in our galaxy by invisible objects with masses between that of Jupiter and a tenth the mass of the Sun. Thus a new component of the mass of our galaxy, dubbed MACHOs, was established (though a diffuse, cold dark matter-like component is still needed to make up most of the galaxy mass). More recently, microlensing led to another exciting discovery—of extra-solar planets with masses ranging from about five times that of Earth to that of Neptune. We can expect many more planets to be discovered through ongoing surveys. Microlensing is the best technique for finding Earth mass planets, though it is not as productive overall as other methods and does not allow for follow up observations. Beyond planet hunting, microlensing has enabled us to observe previously inaccessible systems, ranging from the surfaces of other stars to the accretion disks around the black holes powering distant quasars. Galaxies and galaxy clusters at cosmological distances can produce dramatic lensing effects: multiple images of background galaxies

  1. Asteroseismology of 1523 misclassified red giants using Kepler data

    DEFF Research Database (Denmark)

    Yu, Jie; Huber, Daniel; Bedding, Timothy R.

    2016-01-01

    We analysed solar-like oscillations in 1523 Kepler red giants which have previously been misclassified as subgiants, with predicted nu(max) values [based on the Kepler Input Catalogue (KIC)] between 280 and 700 mu Hz. We report the discovery of 626 new oscillating red giants in our sample......, in addition to 897 oscillators that were previously characterized by Hekker et al. from one quarter of Kepler data. Our sample increases the known number of oscillating low-luminosity red giants by 26 per cent (up to similar to 1900 stars). About three quarters of our sample are classified as ascending red...

  2. The high albedo of the hot Jupiter Kepler-7b

    DEFF Research Database (Denmark)

    Demory, B.-O.; Seager, S.; Madhusudhan, N.

    2011-01-01

    Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations....... The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7 b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass...

  3. Chemical Abundances of M-Dwarfs from the Apogee Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186

    Energy Technology Data Exchange (ETDEWEB)

    Souto, D.; Cunha, K. [Observatório Nacional, Rua General José Cristino, 77, 20921-400 São Cristóvão, Rio de Janeiro, RJ (Brazil); García-Hernández, D. A.; Zamora, O.; Prieto, C. Allende; Jönsson, H.; Pérez, A. E. García [Instituto de Astrofísica de Canarias (IAC), Vía Lactea S/N, E-38205, La Laguna, Tenerife (Spain); Smith, V. V. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Mahadevan, S. [Department of Astronomy and Astrophysics, The Pennsylvania State University (United States); Blake, C. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Johnson, J. A.; Pinsonneault, M. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Holtzman, J. [New Mexico State University, Las Cruces, NM 88003 (United States); Majewski, S. R.; Sobeck, J. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Shetrone, M. [University of Texas at Austin, McDonald Observatory (United States); Teske, J. [Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC 20015 (United States); Nidever, D. [Department of Astronomy, University of Michigan, Ann Arbor, MI, 48104 (United States); Schiavon, R. [Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF (United Kingdom); and others

    2017-02-01

    We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution ( R ∼ 22,500) H -band spectra from the SDSS-IV–APOGEE survey. Chemical abundances of 13 elements—C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe—are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H{sub 2}O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest sub-solar metallicities: [Fe/H]{sub Kepler-138} = −0.09 ± 0.09 dex and [Fe/H]{sub Kepler-186} = −0.08 ± 0.10 dex. The measured metallicities resulting from this high-resolution analysis are found to be higher by ∼0.1–0.2 dex than previous estimates from lower-resolution spectra. The C/O ratios obtained for the two planet-hosting stars are near-solar, with values of 0.55±0.10 for Kepler-138 and 0.52±0.12 for Kepler-186. Kepler-186 exhibits a marginally enhanced [Si/Fe] ratio.

  4. Vascular-targeted photodynamic therapy of gastric antral vascular ectasia (GAVE).

    Science.gov (United States)

    Qiu, Haixia; Mao, Yongping; Zeng, Jing; Wang, Ying; Zhang, Jiaying; Huang, Naiyang; Liu, Qingsen; Yang, Yunsheng; Linghu, Enqiang; Gu, Ying

    2017-01-01

    Vascular-targeted photodynamic therapy (V-PDT) has been used for several benign vascular diseases. The aim of this pilot study was to demonstrate the potential benefits of VPDT in the treatment of gastric antral vascular ectasia (GAVE). Data from patients with GAVE (n=5) who underwent endoscopic V-PDT were analyzed retrospectively. Pre- and post-V-PDT clinical and endoscopic features, hemoglobin levels, and transfusion requirement were compared. The five GAVE patients received one to four sessions of V-PDT. The hemoglobin levels of all five patients increased steadily following V-PDT. Within 6-48months of follow-up, gastrointestinal bleeding and melena disappeared in all five patients and none of the patients needed a transfusion. Endoscopy examinations showed that the dilated vessels had disappeared without scar formation. No significant side effects or adverse reactions were reported. This preliminary study indicates the good selectivity, safety, and efficacy of V-PDT in the treatment of patients with GAVE. Larger prospective studies are needed to further confirm the feasibility of using V-PDT to treat patients with GAVE. Copyright © 2016. Published by Elsevier B.V.

  5. Homogeneous Photodynamical Analysis of Kepler's Multiply-Transiting Systems

    Science.gov (United States)

    Ragozzine, Darin

    To search for planets more like our own, NASA s Kepler Space Telescope ( Kepler ) discovered thousands of exoplanet candidates that cross in front of ( transit ) their parent stars (e.g., Twicken et al. 2016). The Kepler exoplanet data represent an incredible observational leap forward as evidenced by hundreds of papers with thousands of citations. In particular, systems with multiple transiting planets combine the determination of physical properties of exoplanets (e.g., radii), the context provided by the system architecture, and insights from orbital dynamics. Such systems are the most information-rich exoplanetary systems (Ragozzine & Holman 2010). Thanks to Kepler s revolutionary dataset, understanding these Multi-Transiting Systems (MTSs) enables a wide variety of major science questions. In conclusion, existing analyses of MTSs are incomplete and suboptimal and our efficient and timely proposal will provide significant scientific gains ( 100 new mass measurements and 100 updated mass measurements). Furthermore, our homogeneous analysis enables future statistical analyses, including those necessary to characterize the small planet mass-radius relation with implications for understanding the formation, evolution, and habitability of planets. The overarching goal of this proposal is a complete homogeneous investigation of Kepler MTSs to provide detailed measurements (or constraints) on exoplanetary physical and orbital properties. Current investigations do not exploit the full power of the Kepler data; here we propose to use better data (Short Cadence observations), better methods (photodynamical modeling), and a better statistical method (Bayesian Differential Evolution Markov Chain Monte Carlo) in a homogenous analysis of all 700 Kepler MTSs. These techniques are particularly valuable for understanding small terrestrial planets. We propose to extract the near-maximum amount of information from these systems through a series of three research objectives

  6. The California- Kepler Survey. II. Precise Physical Properties of 2025 Kepler Planets and Their Host Stars

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, John Asher; Cargile, Phillip A.; Sinukoff, Evan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Petigura, Erik A.; Howard, Andrew W. [California Institute of Technology, Pasadena, CA, 91125 (United States); Fulton, Benjamin J.; Hirsch, Lea A. [Institute for Astronomy, University of Hawai‘i at Mānoa, Honolulu, HI 96822 (United States); Marcy, Geoffrey W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Hebb, Leslie [Hobart and William Smith Colleges, Geneva, NY 14456 (United States); Morton, Timothy D.; Winn, Joshua N. [Department of Astrophysical Sciences, Peyton Hall, 4 Ivy Lane, Princeton, NJ 08540 (United States); Weiss, Lauren M. [Institut de Recherche sur les Exoplanètes, Université de Montréal, Montréal, QC (Canada); Rogers, Leslie A., E-mail: petigura@caltech.edu [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)

    2017-09-01

    We present stellar and planetary properties for 1305 Kepler Objects of Interest hosting 2025 planet candidates observed as part of the California- Kepler Survey. We combine spectroscopic constraints, presented in Paper I, with stellar interior modeling to estimate stellar masses, radii, and ages. Stellar radii are typically constrained to 11%, compared to 40% when only photometric constraints are used. Stellar masses are constrained to 4%, and ages are constrained to 30%. We verify the integrity of the stellar parameters through comparisons with asteroseismic studies and Gaia parallaxes. We also recompute planetary radii for 2025 planet candidates. Because knowledge of planetary radii is often limited by uncertainties in stellar size, we improve the uncertainties in planet radii from typically 42% to 12%. We also leverage improved knowledge of stellar effective temperature to recompute incident stellar fluxes for the planets, now precise to 21%, compared to a factor of two when derived from photometry.

  7. Asteroseismic inversions in the Kepler era: application to the Kepler Legacy sample

    Science.gov (United States)

    Buldgen, Gaël; Reese, Daniel; Dupret, Marc-Antoine

    2017-10-01

    In the past few years, the CoRoT and Kepler missions have carried out what is now called the space photometry revolution. This revolution is still ongoing thanks to K2 and will be continued by the Tess and Plato2.0 missions. However, the photometry revolution must also be followed by progress in stellar modelling, in order to lead to more precise and accurate determinations of fundamental stellar parameters such as masses, radii and ages. In this context, the long-lasting problems related to mixing processes in stellar interior is the main obstacle to further improvements of stellar modelling. In this contribution, we will apply structural asteroseismic inversion techniques to targets from the Kepler Legacy sample and analyse how these can help us constrain the fundamental parameters and mixing processes in these stars. Our approach is based on previous studies using the SOLA inversion technique [1] to determine integrated quantities such as the mean density [2], the acoustic radius, and core conditions indicators [3], and has already been successfully applied to the 16Cyg binary system [4]. We will show how this technique can be applied to the Kepler Legacy sample and how new indicators can help us to further constrain the chemical composition profiles of stars as well as provide stringent constraints on stellar ages.

  8. KEPLER ECLIPSING BINARY STARS. III. CLASSIFICATION OF KEPLER ECLIPSING BINARY LIGHT CURVES WITH LOCALLY LINEAR EMBEDDING

    International Nuclear Information System (INIS)

    Matijevič, Gal; Prša, Andrej; Orosz, Jerome A.; Welsh, William F.; Bloemen, Steven; Barclay, Thomas

    2012-01-01

    We present an automated classification of 2165 Kepler eclipsing binary (EB) light curves that accompanied the second Kepler data release. The light curves are classified using locally linear embedding, a general nonlinear dimensionality reduction tool, into morphology types (detached, semi-detached, overcontact, ellipsoidal). The method, related to a more widely used principal component analysis, produces a lower-dimensional representation of the input data while preserving local geometry and, consequently, the similarity between neighboring data points. We use this property to reduce the dimensionality in a series of steps to a one-dimensional manifold and classify light curves with a single parameter that is a measure of 'detachedness' of the system. This fully automated classification correlates well with the manual determination of morphology from the data release, and also efficiently highlights any misclassified objects. Once a lower-dimensional projection space is defined, the classification of additional light curves runs in a negligible time and the method can therefore be used as a fully automated classifier in pipeline structures. The classifier forms a tier of the Kepler EB pipeline that pre-processes light curves for the artificial intelligence based parameter estimator.

  9. Simple derivations of Kepler's first law: use of complex variables

    International Nuclear Information System (INIS)

    Xu Donghui

    2012-01-01

    By making use of complex variables, simple derivations of Kepler's first law are introduced. Such derivations might be of interest for undergraduate students in an introductory physics course. (paper)

  10. Introducing Triquetrum, A Possible Future for Kepler and Ptolemy II

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Christopher [University of California, Berkeley; Billings, Jay Jay [ORNL

    2016-01-01

    Triquetrum is an open platform for managing and executing scientific workflows that is under development as an Eclipse project. Both Triquetrum and Kepler use Ptolemy II as their execution engine. Triquetrum presents opportunities and risks for the Kepler community. The opportunities include a possibly larger community for interaction and a path for Kepler to move from Kepler's one-off ant-based build environment towards a more common OSGi-based environment and a way to maintain a stable Ptolemy II core. The risks include the fact that Triquetrum is a fork of Ptolemy II that would result in package name changes and other possible changes. In addition, Triquetrum is licensed under the Eclipse Public License v1.0, which includes a patent clause that could conflict with the University of California patent clause. This paper describes these opportunities and risks.

  11. Gravitational lensing by rotating wormholes

    Science.gov (United States)

    Jusufi, Kimet; Ã-vgün, Ali

    2018-01-01

    In this paper the deflection angle of light by a rotating Teo wormhole spacetime is calculated in the weak limit approximation. We mainly focus on the weak deflection angle by revealing the gravitational lensing as a partially global topological effect. We apply the Gauss-Bonnet theorem (GBT) to the optical geometry osculating the Teo-Randers wormhole optical geometry to calculate the deflection angle. Furthermore we find the same result using the standard geodesic method. We have found that the deflection angle can be written as a sum of two terms, namely the first term is proportional to the throat of the wormhole and depends entirely on the geometry, while the second term is proportional to the spin angular momentum parameter of the wormhole. A direct observation using lensing can shed light and potentially test the nature of rotating wormholes by comparing with the black holes systems.

  12. A system of catoptric lenses

    International Nuclear Information System (INIS)

    McFarland, P.J.; Rambauske, W.R.

    1973-01-01

    Description is given of a system of catoptric lenses for combining energies provided by a certain number of sources, e.g. optical energies provided by a certain number of lasers. This system comprises sets of mirrors the reflecting surfaces of which have their focuses spaced from a common axis. The mirrors of all these sets are arranged on a common frame, which makes aperture-locking impossible. This can be applied to thermonuclear fusion [fr

  13. INITIAL DATA RELEASE OF THE KEPLER-INT SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Greiss, S.; Steeghs, D.; Gaensicke, B. T. [Department of Physics, Astronomy and Astrophysics group, University of Warwick, CV4 7AL Coventry (United Kingdom); Martin, E. L. [INTA-CSIC Centro de Astrobiologia, Carretera de Ajalvir km 4, 28550 Torrejon de Ardoz (Spain); Groot, P. J.; Verbeek, K.; Jonker, P. G.; Scaringi, S. [Department of Astrophysics/IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Irwin, M. J.; Gonzalez-Solares, E. [Cambridge Astronomy Survey Unit, Institute of Astronomy, University of Cambridge, Madingley Road, CB3 0HA Cambridge (United Kingdom); Greimel, R. [Institut fuer Physik, Karl-Franzen Universitaet Graz, Universitaetsplatz 5, 8010 Graz (Austria); Knigge, C. [School of Physics and Astronomy, University of Southampton, Southampton, Hampshire SO17 1BJ (United Kingdom); Ostensen, R. H. [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Drew, J. E.; Farnhill, H. [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Drake, J.; Wright, N. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ripepi, V. [INAF-Osservatorio Astronomico di Capodimonte, via Moiariello 16, Naples I-80131 (Italy); Southworth, J. [Astrophysics Group, Keele University, Newcastle-under-Lyme ST5 5BG (United Kingdom); Still, M., E-mail: s.greiss@warwick.ac.uk [NASA Ames Research Center, M/S 244-40, Moffett Field, CA 94035 (United States); and others

    2012-07-15

    This paper describes the first data release of the Kepler-INT Survey (KIS) that covers a 116 deg{sup 2} region of the Cygnus and Lyra constellations. The Kepler field is the target of the most intensive search for transiting planets to date. Despite the fact that the Kepler mission provides superior time-series photometry, with an enormous impact on all areas of stellar variability, its field lacks optical photometry complete to the confusion limit of the Kepler instrument necessary for selecting various classes of targets. For this reason, we follow the observing strategy and data reduction method used in the IPHAS and UVEX galactic plane surveys in order to produce a deep optical survey of the Kepler field. This initial release concerns data taken between 2011 May and August, using the Isaac Newton Telescope on the island of La Palma. Four broadband filters were used, U, g, r, i, as well as one narrowband one, H{alpha}, reaching down to a 10{sigma} limit of {approx}20th mag in the Vega system. Observations covering {approx}50 deg{sup 2}, thus about half of the field, passed our quality control thresholds and constitute this first data release. We derive a global photometric calibration by placing the KIS magnitudes as close as possible to the Kepler Input Catalog (KIC) photometry. The initial data release catalog containing around 6 million sources from all the good photometric fields is available for download from the KIS Web site (www.astro.warwick.ac.uk/research/kis/) as well as via MAST (KIS magnitudes can be retrieved using the MAST enhanced target search page http://archive.stsci.edu/kepler/kepler{sub f}ov/search.php and also via Casjobs at MAST Web site http://mastweb.stsci.edu/kplrcasjobs/).

  14. Preparation of Kepler light curves for asteroseismic analyses

    DEFF Research Database (Denmark)

    García, R.A.; Hekker, Saskia; Stello, Dennis

    2011-01-01

    The Kepler mission is providing photometric data of exquisite quality for the asteroseismic study of different classes of pulsating stars. These analyses place particular demands on the pre-processing of the data, over a range of time-scales from minutes to months. Here, we describe processing...... procedures developed by the Kepler Asteroseismic Science Consortium to prepare light curves that are optimized for the asteroseismic study of solar-like oscillating stars in which outliers, jumps and drifts are corrected....

  15. Ground-based observations of Kepler asteroseismic targets

    DEFF Research Database (Denmark)

    Uyttterhoeven , K.; Karoff, Christoffer

    2010-01-01

    We present the ground-based activities within the different working groups of the Kepler Asteroseismic Science Consortium (KASC). The activities aim at the systematic characterization of the 5000+ KASC targets, and at the collection of ground-based follow-up time-series data of selected promising...... Kepler pulsators. So far, 36 different instruments at 31 telescopes on 23 different observatories in 12 countries are in use, and a total of more than 530 observing nights has been awarded....

  16. INITIAL DATA RELEASE OF THE KEPLER-INT SURVEY

    International Nuclear Information System (INIS)

    Greiss, S.; Steeghs, D.; Gänsicke, B. T.; Martín, E. L.; Groot, P. J.; Verbeek, K.; Jonker, P. G.; Scaringi, S.; Irwin, M. J.; González-Solares, E.; Greimel, R.; Knigge, C.; Østensen, R. H.; Drew, J. E.; Farnhill, H.; Drake, J.; Wright, N. J.; Ripepi, V.; Southworth, J.; Still, M.

    2012-01-01

    This paper describes the first data release of the Kepler-INT Survey (KIS) that covers a 116 deg 2 region of the Cygnus and Lyra constellations. The Kepler field is the target of the most intensive search for transiting planets to date. Despite the fact that the Kepler mission provides superior time-series photometry, with an enormous impact on all areas of stellar variability, its field lacks optical photometry complete to the confusion limit of the Kepler instrument necessary for selecting various classes of targets. For this reason, we follow the observing strategy and data reduction method used in the IPHAS and UVEX galactic plane surveys in order to produce a deep optical survey of the Kepler field. This initial release concerns data taken between 2011 May and August, using the Isaac Newton Telescope on the island of La Palma. Four broadband filters were used, U, g, r, i, as well as one narrowband one, Hα, reaching down to a 10σ limit of ∼20th mag in the Vega system. Observations covering ∼50 deg 2 , thus about half of the field, passed our quality control thresholds and constitute this first data release. We derive a global photometric calibration by placing the KIS magnitudes as close as possible to the Kepler Input Catalog (KIC) photometry. The initial data release catalog containing around 6 million sources from all the good photometric fields is available for download from the KIS Web site (www.astro.warwick.ac.uk/research/kis/) as well as via MAST (KIS magnitudes can be retrieved using the MAST enhanced target search page http://archive.stsci.edu/kepler/kepler_fov/search.php and also via Casjobs at MAST Web site http://mastweb.stsci.edu/kplrcasjobs/).

  17. KEPLER OBSERVATIONS OF TRANSITING HOT COMPACT OBJECTS

    International Nuclear Information System (INIS)

    Rowe, Jason F.; Borucki, William J.; Koch, David; Lissauer, Jack J.; Howell, Steve B.; Basri, Gibor; Marcy, Geoff; Batalha, Natalie; Brown, Timothy M.; Caldwell, Douglas; Jenkins, Jon; Cochran, William D.; Dunham, Edward; Dupree, Andrea K.; Latham, David W.; Sasselov, Dimitar; Fortney, Jonathan J.; Gautier, Thomas N.; Gilliland, Ronald L.; Monet, David G.

    2010-01-01

    Kepler photometry has revealed two unusual transiting companions: one orbiting an early A-star and the other orbiting a late B-star. In both cases, the occultation of the companion is deeper than the transit. The occultation and transit with follow-up optical spectroscopy reveal a 9400 K early A-star, KOI-74 (KIC 6889235), with a companion in a 5.2 day orbit with a radius of 0.08 R sun and a 10,000 K late B-star KOI-81 (KIC 8823868) that has a companion in a 24 day orbit with a radius of 0.2 R sun . We infer a temperature of 12,250 K for KOI-74b and 13,500 K for KOI-81b. We present 43 days of high duty cycle, 30 minute cadence photometry, with models demonstrating the intriguing properties of these objects, and speculate on their nature.

  18. Solving Kepler's equation using implicit functions

    Science.gov (United States)

    Mortari, Daniele; Elipe, Antonio

    2014-01-01

    A new approach to solve Kepler's equation based on the use of implicit functions is proposed here. First, new upper and lower bounds are derived for two ranges of mean anomaly. These upper and lower bounds initialize a two-step procedure involving the solution of two implicit functions. These two implicit functions, which are non-rational (polynomial) Bézier functions, can be linear or quadratic, depending on the derivatives of the initial bound values. These are new initial bounds that have been compared and proven more accurate than Serafin's bounds. The procedure reaches machine error accuracy with no more that one quadratic and one linear iterations, experienced in the "tough range", where the eccentricity is close to one and the mean anomaly to zero. The proposed method is particularly suitable for space-based applications with limited computational capability.

  19. Kepler constraints on planets near hot Jupiters.

    Science.gov (United States)

    Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

    2012-05-22

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  20. Kepler constraints on planets near hot Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Fabrycky, Daniel C.; /UC, Santa Cruz, Astron. Astrophys.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames; Welsh, William F.; /San Diego State U., Astron. Dept.; Borucki, William J.; /NASA, Ames; Boss, Alan P.; /Carnegie Inst., Wash., D.C., DTM; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

    2012-05-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2:1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  1. Computing on Knights and Kepler Architectures

    International Nuclear Information System (INIS)

    Bortolotti, G; Caberletti, M; Ferraro, A; Giacomini, F; Manzali, M; Maron, G; Salomoni, D; Crimi, G; Zanella, M

    2014-01-01

    A recent trend in scientific computing is the increasingly important role of co-processors, originally built to accelerate graphics rendering, and now used for general high-performance computing. The INFN Computing On Knights and Kepler Architectures (COKA) project focuses on assessing the suitability of co-processor boards for scientific computing in a wide range of physics applications, and on studying the best programming methodologies for these systems. Here we present in a comparative way our results in porting a Lattice Boltzmann code on two state-of-the-art accelerators: the NVIDIA K20X, and the Intel Xeon-Phi. We describe our implementations, analyze results and compare with a baseline architecture adopting Intel Sandy Bridge CPUs.

  2. Absolute densities in exoplanetary systems. Photodynamical modelling of Kepler-138.

    Science.gov (United States)

    Almenara, J. M.; Díaz, R. F.; Dorn, C.; Bonfils, X.; Udry, S.

    2018-04-01

    In favourable conditions, the density of transiting planets in multiple systems can be determined from photometry data alone. Dynamical information can be extracted from light curves, providing modelling is done self-consistently, i.e. using a photodynamical model, which simulates the individual photometric observations instead of the more generally used transit times. We apply this methodology to the Kepler-138 planetary system. The derived planetary bulk densities are a factor of two more precise than previous determinations, and we find a discrepancy in the stellar bulk density with respect to a previous study. This leads, in turn, to a discrepancy in the determination of masses and radii of the star and the planets. In particular, we find that interior planet, Kepler-138 b, has a size in between Mars and the Earth. Given our mass and density estimates, we characterize the planetary interiors using a generalized Bayesian inference model. This model allows us to quantify for interior degeneracy and calculate confidence regions of interior parameters such as thicknesses of the core, the mantle, and ocean and gas layers. We find that Kepler-138 b and Kepler-138 d have significantly thick volatile layers, and that the gas layer of Kepler-138 b is likely enriched. On the other hand, Kepler-138 c can be purely rocky.

  3. 30 CFR 18.30 - Windows and lenses.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Windows and lenses. 18.30 Section 18.30 Mineral... § 18.30 Windows and lenses. (a) MSHA may waive testing of materials for windows or lenses except headlight lenses. When tested, material for windows or lenses shall meet the test requirements prescribed in...

  4. Planck 2015 results. XV. Gravitational lensing

    CERN Document Server

    Ade, P.A.R.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Church, S.; 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.; Désert, F.-X.; Diego, J.M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; 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.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P.B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P.M.; Macías-Pérez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P.G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Nørgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G.W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J.P.; Reach, W.T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; White, M.; Yvon, D.; Zacchei, A.

    2016-01-01

    We present the most significant measurement of the cosmic microwave background (CMB) lensing potential to date (at a level of 40 sigma), using temperature and polarization data from the Planck 2015 full-mission release. Using a polarization-only estimator we detect lensing at a significance of 5 sigma. We cross-check the accuracy of our measurement using the wide frequency coverage and complementarity of the temperature and polarization measurements. Public products based on this measurement include an estimate of the lensing potential over approximately 70% of the sky, an estimate of the lensing potential power spectrum in bandpowers for the multipole range 40lensing potential power spectrum and that found in the best-fitting LCDM model based on the Planck temperature and polarization power spectra. Using the lensing likelihood alone we obtain a percent-level measurement of ...

  5. Scleral lenses in the management of keratoconus.

    Science.gov (United States)

    Schornack, Muriel M; Patel, Sanjay V

    2010-01-01

    To describe the use of Jupiter scleral lenses (Medlens Innovations, Front Royal, VA; and Essilor Contact Lenses, Inc., Dallas, TX) in the management of keratoconus. We performed a single-center retrospective chart review of our initial 32 patients with keratoconus evaluated for scleral lens wear. All patients were referred for scleral lens evaluation after exhausting other nonsurgical options for visual correction. Diagnostic lenses were used in the initial fitting process. If adequate fit could not be achieved with standard lenses, custom lenses were designed in consultation with the manufacturers' specialists. The following measures were evaluated for each patient: ability to tolerate and handle lenses, visual acuity with scleral lenses, number of lenses, and visits needed to complete the fitting process. Fifty-two eyes of 32 patients were evaluated for scleral lens wear. Of these, 12 patients (20 eyes) decided not to pursue scleral lens wear after initial evaluation. One patient (2 eyes) abandoned the fitting process after cataract surgery. The remaining 19 patients (30 eyes) were fit successfully. The average number of lenses ordered per eye was 1.5. The fitting process required an average of 2.8 visits. Standard lenses were prescribed for 23 eyes, and custom designs were needed for 7 eyes. Median best-corrected visual acuity improved from 20/40 (mean, 20/76) before scleral lens fitting to 20/20 (mean, 20/30) after fitting. Follow-up ranged from 3 to 32 months. Jupiter scleral lenses provide acceptable visual acuity and comfort in patients with keratoconus. The availability of diagnostic lenses facilitates the fitting process.

  6. The Kepler Dichotomy in Planetary Disks: Linking Kepler Observables to Simulations of Late-stage Planet Formation

    Science.gov (United States)

    Moriarty, John; Ballard, Sarah

    2016-11-01

    NASA’s Kepler Mission uncovered a wealth of planetary systems, many with planets on short-period orbits. These short-period systems reside around 50% of Sun-like stars and are similarly prevalent around M dwarfs. Their formation and subsequent evolution is the subject of active debate. In this paper, we simulate late-stage, in situ planet formation across a grid of planetesimal disks with varying surface density profiles and total mass. We compare simulation results with observable characteristics of the Kepler sample. We identify mixture models with different primordial planetesimal disk properties that self-consistently recover the multiplicity, radius, period and period ratio, and duration ratio distributions of the Kepler planets. We draw three main conclusions. (1) We favor a “frozen-in” narrative for systems of short-period planets, in which they are stable over long timescales, as opposed to metastable. (2) The “Kepler dichotomy,” an observed phenomenon of the Kepler sample wherein the architectures of planetary systems appear to either vary significantly or have multiple modes, can naturally be explained by formation within planetesimal disks with varying surface density profiles. Finally, (3) we quantify the nature of the “Kepler dichotomy” for both GK stars and M dwarfs, and find that it varies with stellar type. While the mode of planet formation that accounts for high multiplicity systems occurs in 24% ± 7% of planetary systems orbiting GK stars, it occurs in 63% ± 16% of planetary systems orbiting M dwarfs.

  7. The Kepler DB, a Database Management System for Arrays, Sparse Arrays and Binary Data

    Science.gov (United States)

    McCauliff, Sean; Cote, Miles T.; Girouard, Forrest R.; Middour, Christopher; Klaus, Todd C.; Wohler, Bill

    2010-01-01

    The Kepler Science Operations Center stores pixel values on approximately six million pixels collected every 30-minutes, as well as data products that are generated as a result of running the Kepler science processing pipeline. The Kepler Database (Kepler DB) management system was created to act as the repository of this information. After one year of ight usage, Kepler DB is managing 3 TiB of data and is expected to grow to over 10 TiB over the course of the mission. Kepler DB is a non-relational, transactional database where data are represented as one dimensional arrays, sparse arrays or binary large objects. We will discuss Kepler DB's APIs, implementation, usage and deployment at the Kepler Science Operations Center.

  8. Braneworld Black Hole Gravitational Lensing

    International Nuclear Information System (INIS)

    Liang Jun

    2017-01-01

    A class of braneworld black holes, which I called as Bronnikov–Melnikov–Dehen (BMD) black holes, are studied as gravitational lenses. I obtain the deflection angle in the strong deflection limit, and further calculate the angular positions and magnifications of relativistic images as well as the time delay between different relativistic images. I also compare the results with those obtained for Schwarzschild and two braneworld black holes, i.e., the tidal Reissner-Nordström (R-N) and the Casadio–Fabbri–Mazzacurati (CFM) black holes. (paper)

  9. The Scales of Gravitational Lensing

    Directory of Open Access Journals (Sweden)

    Francesco De Paolis

    2016-03-01

    Full Text Available After exactly a century since the formulation of the general theory of relativity, the phenomenon of gravitational lensing is still an extremely powerful method for investigating in astrophysics and cosmology. Indeed, it is adopted to study the distribution of the stellar component in the Milky Way, to study dark matter and dark energy on very large scales and even to discover exoplanets. Moreover, thanks to technological developments, it will allow the measure of the physical parameters (mass, angular momentum and electric charge of supermassive black holes in the center of ours and nearby galaxies.

  10. DENSITY AND ECCENTRICITY OF KEPLER PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yanqin [Department of Astronomy and Astrophysics, University of Toronto, ON M5S 3H4 (Canada); Lithwick, Yoram [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2013-07-20

    We analyze the transit timing variations (TTV) obtained by the Kepler mission for 22 sub-Jovian planet pairs (19 published, 3 new) that lie close to mean motion resonances. We find that the TTV phases for most of these pairs lie close to zero, consistent with an eccentricity distribution that has a very low root-mean-squared value of e {approx} 0.01; but about a quarter of the pairs possess much higher eccentricities, up to e {approx} 0.1-0.4. For the low-eccentricity pairs, we are able to statistically remove the effect of eccentricity to obtain planet masses from TTV data. These masses, together with those measured by radial velocity, yield a best-fit mass-radius relation M {approx} 3 M{sub Circled-Plus }(R/R{sub Circled-Plus }). This corresponds to a constant surface escape velocity of {approx}20 km s{sup -1}. We separate the planets into two distinct groups: ''mid-sized'' (those greater than 3 R{sub Circled-Plus }) and 'compact' (those smaller). All mid-sized planets are found to be less dense than water and therefore must contain extensive H/He envelopes that are comparable in mass to that of their cores. We argue that these planets have been significantly sculpted by photoevaporation. Surprisingly, mid-sized planets, a minority among Kepler candidates, are discovered exclusively around stars more massive than 0.8 M{sub Sun }. The compact planets, on the other hand, are often denser than water. Combining our density measurements with those from radial velocity studies, we find that hotter compact planets tend to be denser, with the hottest ones reaching rock density. Moreover, hotter planets tend to be smaller in size. These results can be explained if the compact planets are made of rocky cores overlaid with a small amount of hydrogen, {<=}1% in mass, with water contributing little to their masses or sizes. Photoevaporation has exposed bare rocky cores in cases of the hottest planets. Our conclusion that these planets are likely

  11. Kepler-68: Three Planets, One with a Density between that of Earth and Ice Giants

    NARCIS (Netherlands)

    Gilliland, R.L.; Marcy, G.W.; Rowe, J.F.; Rogers, L.; Torres, G.; Fressin, F.; Lopez, E.D.; Buchhave, L.A.; Christensen-Dalsgaard, J.; Désert, J.M.; Henze, C.E.; Isaacson, H.; Jenkins, J.M.; Lissauer, J.J.; Chaplin, W.J.; Basu, S.; Metcalfe, T.S.; Elsworth, Y.; Handberg, R.; Hekker, S.; Huber, D.; Karoff, C.; Kjeldsen, H.; Lund, M.N.; Lundkvist, M.; Miglio, A.; Charbonneau, D.; Ford, E.B.; Fortney, J.J.; Haas, M.R.; Howard, A.W.; Howell, S.B.; Ragozzine, D.; Thompson, S.E.

    2013-01-01

    NASA's Kepler Mission has revealed two transiting planets orbiting Kepler-68. Follow-up Doppler measurements have established the mass of the innermost planet and revealed a third Jovian-mass planet orbiting beyond the two transiting planets. Kepler-68b, in a 5.4 day orbit, has Mp_{\\rm

  12. VizieR Online Data Catalog: Catalog of Kepler flare stars (Van Doorsselaere+, 2017)

    Science.gov (United States)

    van Doorsselaere, T.; Shariati, H.; Debosscher, J.

    2017-11-01

    With an automated detection method, we have identified stellar flares in the long cadence observations of Kepler during quarter 15. We list each flare time for the respective Kepler objects. Furthermore, we list the flare amplitude and decay time after fitting the flare light curve with an exponential decay. Flare start times in long cadence data of Kepler during quarter 15. (1 data file).

  13. Discovery and Rossiter-McLauglin effect of exoplanet kepler-8b

    DEFF Research Database (Denmark)

    Jenkins...[], Jon M.; Borucki, W.J.; Koch, D. G.

    2010-01-01

    We report on the discovery and the Rossiter-McLaughlin (R-M) effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius R P ...

  14. Take off with NASA's Kepler Mission!: The Search for Other "Earths"

    Science.gov (United States)

    Koch, David; DeVore, Edna K.; Gould, Alan; Harman, Pamela

    2009-01-01

    Humans have long wondered about life in the universe. Are we alone? Is Earth unique? What is it that makes our planet a habitable one, and are there others like Earth? NASA's Kepler Mission seeks the answers to these questions. Kepler is a space-based, specially designed 0.95 m aperture telescope. Launching in 2009, Kepler is NASA's first mission…

  15. The kinematical structure of gravitationally lensed arcs

    NARCIS (Netherlands)

    Moller, O; Noordermeer, E

    2006-01-01

    In this paper, the expected properties of the velocity fields of strongly lensed arcs behind galaxy clusters are investigated. The velocity profile along typical lensed arcs is determined by ray-tracing light rays from a model source galaxy through parametric cluster toy models consisting of

  16. Modern scleral lenses part I: clinical features.

    NARCIS (Netherlands)

    Visser, E.S.; Visser, R.; Lier, H.J.J. van; Otten, H.M.

    2007-01-01

    PURPOSE: To evaluate the indications for modern scleral lenses and their clinical performance in patients who were fitted with scleral lenses at the authors' practices. METHODS: In this cross-sectional survey, all the necessary data were obtained at the first follow-up visit during the 5-month study

  17. Soft Lenses | Kuming | South African Medical Journal

    African Journals Online (AJOL)

    A series of cases fitted with Bionite soft lenses is described. Good results were obtained in bullous keratopathy, dry eyes, early and moderately advanced Stevens-Johnson syndrome and pemphigoid, and some cases of indolent corneal ulcers. The lenses appear to be a most effective replacement for tarsorrhaphy, haptic ...

  18. The Albedo of Kepler's Small Worlds

    Science.gov (United States)

    Jansen, Tiffany; Kipping, David

    2018-01-01

    The study of exoplanet phase curves has been established as a powerful tool for measuring the atmospheric properties of other worlds. To first order, phase curves have the same amplitude as occultations, yet far greater temporal baselines enabling substantial improvements in sensitivity. Even so, only a relatively small fraction of Kepler planets have detectable phase curves, leading to a population dominated by hot-Jupiters. One way to boost sensitivity further is to stack different planets of similar types together, giving rise to an average phase curve for a specific ensemble. In this work, we measure the average albedo, thermal redistribution efficiency, and greenhouse boosting factor from the average phase curves of 115 Neptunian and 50 Terran (solid) worlds. We construct ensemble phase curve models for both samples accounting for the reflection and thermal components and regress our models assuming a global albedo, redistribution factor and greenhouse factor in a Bayesian framework. We find modest evidence for a detected phase curve in the Neptunian sample, although the albedo and thermal properties are somewhat degenerate meaning we can only place an upper limit on the albedo of Ag < 0.23 and greenhouse factor of f < 1.40 to 95% confidence. As predicted theoretically, this confirms hot-Neptunes are darker than Neptune and Uranus. Additionally, we place a constraint on the albedo of solid, Terran worlds of Ag < 0.42 and f < 1.60 to 95% confidence, compatible with a dark Lunar-like surface.

  19. Confirmation of Kepler Planet Candidates around Giants

    Science.gov (United States)

    Sato, Bun-ei

    2014-01-01

    Detecting planetary transits is extremely valuable not only because it makes an independent confirmation of a planet from Doppler method but also because the photometric transits yield unambiguous information on planet masses and radii, and thus mean density and interior structure, and obliquity of planetary orbits. Planets around giants and subgiants have been intensively surveyed over the decade by precise radial velocity (RV) measurements, mainly from the viewpoint of planet searches around intermediate-mass (1.5-5M⊙) stars. The planets show remarkable properties in their masses and orbital parameters. Unfortunately, however, it is quite difficult to detect transiting ones around such evolved stars because of the large sizes of the host stars. Therefore, our understanding of properties of planets around intermediate-mass stars are still far behind from those around solar-like stars. In S13B, we made the first RV follow-up observations with HDS for the transiting planet candidates around giants found by Kepler space telescope, and identified promising candidates of true transiting planets. Here we propose to take additional RV data for them with HDS in order to make sure that the RV periodicity is the same as the transit one.

  20. Management and Systems Engineering of the Kepler Mission

    Science.gov (United States)

    Fanson, James; Livesay, Leslie; Frerking, Margaret; Cooke, Brian

    2010-01-01

    Kepler is the National Aeronautics and Space Administration's (NASA's) first mission capable of detecting Earth-size planets orbiting in the habitable zones around stars other than the sun. Selected for implementation in 2001 and launched in 2009, Kepler seeks to determine whether Earth-like planets are common or rare in the galaxy. The investigation requires a large, space-based photometer capable of simultaneously measuring the brightnesses of 100,000 stars at part-per-million level of precision. This paper traces the development of the mission from the perspective of project management and systems engineering and describes various methodologies and tools that were found to be effective. The experience of the Kepler development is used to illuminate lessons that can be applied to future missions.

  1. Classical dynamical systems with the symmetry of the Kepler problem

    International Nuclear Information System (INIS)

    Karloukovski, V.I.

    1978-01-01

    The Hamiltonian dynamical systems of the form of H=1/2G 1 p 2 +1/2G 2 (xp) 2 +G 3 (xp)+U, where Gsub(j) and U are functions of r= √ x 2 , are investigated. The notion of the strict Kepler symmetry is introduced to single out the cases where there is the Runge-Lenz vector quadratic in the momentum. All dynamical systems with this property are found. They depend on an arbitrary function of the distance to the centrum of symmetry and two arbitrary interaction constants. The equations of motion are solved and it is shown explicitly that the orbits are closed. Cases when the strict Kepler symmetry is related to an underlying E(3) symmetry are noted. The breaking of the strict Kepler symmetry and its relation to the precession of the perihelium are discussed

  2. DISCOVERY OF A ZZ CETI IN THE KEPLER MISSION FIELD

    International Nuclear Information System (INIS)

    Hermes, J. J.; Winget, D. E.; Mullally, Fergal; Howell, Steve B.; Oestensen, R. H.; Bloemen, S.; Williams, Kurtis A.; Telting, John; Southworth, John; Everett, Mark

    2011-01-01

    We report the discovery of the first identified pulsating DA white dwarf, WD J1916+3938 (Kepler ID 4552982), in the field of the Kepler mission. This ZZ Ceti star was first identified through ground-based, time-series photometry, and follow-up spectroscopy confirms that it is a hydrogen-atmosphere white dwarf with T eff = 11,129 ± 115 K and log g = 8.34 ± 0.06, placing it within the empirical ZZ Ceti instability strip. The object shows up to 0.5% amplitude variability at several periods between 800 and 1450 s. Extended Kepler observations of WD J1916+3938 could yield the best light curve, to date, of any pulsating white dwarf, allowing us to directly study the interior of an evolved object representative of the fate of the majority of stars in our Galaxy.

  3. Scanning Miniature Microscopes without Lenses

    Science.gov (United States)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  4. No Metallicity Correlation Associated with the Kepler Dichotomy

    Science.gov (United States)

    Munoz Romero, Carlos E.; Kempton, Eliza M.-R.

    2018-03-01

    NASA’s Kepler mission has discovered thousands of planetary systems, ∼20% of which are found to host multiple transiting planets. This relative paucity (compared to the high fraction of single transiting systems) is postulated to result from a distinction in the architecture between multi-transiting systems and those hosting a single transiting planet: a phenomenon usually referred to as the Kepler dichotomy. In this paper, we investigate the hypothesis that external giant planets are the main cause behind the over-abundance of single- relative to multi-transiting systems, which would be signaled by higher metallicities in the former sample. To this end, we perform a statistical analysis on the stellar metallicity distribution with respect to planet multiplicity in the Kepler data. We perform our analysis on a variety of samples taken from a population of 1166 Kepler main-sequence planetary hosts, using precisely determined metallicities from the California-Kepler survey and Swift et al. Contrary to some predictions, we do not find a significant difference between the stellar metallicities of the single- and multiple-transiting planet systems. However, we do find a 55% upper bound for systems with a single non-giant planet that could also host a hidden giant planet, based on metallicity considerations. While the presence of external giant planets might be one factor behind the Kepler dichotomy, our results also favor alternative explanations. We suggest that additional radial velocity and direct imaging measurements are necessary to constrain the presence of gas giants in systems with a single transiting planet.

  5. From emblems to diagrams: Kepler's new pictorial language of scientific representation.

    Science.gov (United States)

    Chen-Morris, Raz

    2009-01-01

    Kepler's treatise on optics of 1604 furnished, along with technical solutions to problems in medieval perspective, a mathematically-based visual language for the observation of nature. This language, based on Kepler's theory of retinal pictures, ascribed a new role to geometrical diagrams. This paper examines Kepler's pictorial language against the backdrop of alchemical emblems that flourished in and around the court of Rudolf II in Prague. It highlights the cultural context in which Kepler's optics was immersed, and the way in which Kepler attempted to demarcate his new science from other modes of the investigation of nature.

  6. Kepler-16 Circumbinary System Validates Quantum Celestial Mechanics

    Directory of Open Access Journals (Sweden)

    Potter F.

    2012-01-01

    Full Text Available We report the application of quantum celestial mechanics (QCM to the Kepler-16 cir- cumbinary system which has a single planet orbiting binary stars with the important system parameters known to within one percent. Other gravitationally bound systems such as the Solar System of planets and the Jovian satellite systems have large uncertain- ties in their total angular momentum. Therefore, Kepler-16 allows us for the first time to determine whether the QCM predicted angular momentum per mass quantization is valid.

  7. Asteroseismology of Kepler ZZ Ceti Stars with Fully Evolutionary Models

    Science.gov (United States)

    Romero, A. D.; Córsico, A. H.; Castanheira, B. G.; De Gerónimo, F. C.; Kepler, S. O.; Althaus, L. G.; Koester, D.; Kawka, A.; Gianninas, A.; Bonato, C.

    2017-03-01

    Recently the Kepler spacecraft observed ZZ Ceti stars giving the opportunity to study their variability for long baselines. We present a study of pulsational properties of two ZZ Ceti stars observed with the Kepler spacecraft: GD 1212 and SDSS J113655.17+040952.6, based on a grid of full evolutionary models of DA white dwarf stars, characterized by detailed and consistent inner chemical profiles. For J113655.17+040952 we found values of gravity and effective temperature in good agreement with spectroscopy. For GD 1212 the asteroseismological fits show a stellar mass higher than the spectroscopic value, but in agreement with the determinations from photometry coupled with parallax.

  8. Characterization of small planets with Kepler and HARPS-N

    Directory of Open Access Journals (Sweden)

    Bonomo A. S.

    2015-01-01

    Full Text Available The high-accuracy and high-precision HARPS-N spectrograph has been installed at the italian Telescopio Nazionale Galileo in La Palma approximately two years and a half ago. Eighty nights per year of Guaranteed Time of Observation are mostly dedicated to the radial-velocity (RV follow up of Kepler small-size planetary candidates to establish their nature and to determine accurately their masses. We report on recent results of this ongoing RV campaign, including the recent characterization of the planetary system Kepler-101.

  9. Exoplanet Science from NASA’s Kepler Mission

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason [Northwestern University

    2012-09-12

    NASA's exoplanet mission is the world's premier instrument for the discovery and study of planets orbiting distant stars. As the nominal mission comes to a close, Kepler has discovered nearly 2500 planet candidates, confirmed dozens of multi-planet systems, provided important insights into the orbital architectures of planetary systems, identified specific systems that challenge theories of planet formation and dynamical evolution, has revolutionized our understanding of stellar interiors, and is gearing to measure the frequency of Earth-like planets in the habitable zones of Sun-like stars in its extended mission phase. I present the most recent results from the Kepler mission.

  10. Kepler and the origins of pre-Newtonian mass

    Science.gov (United States)

    Hecht, Eugene

    2017-02-01

    The technical concept of "mass" is traced from its medieval origins in theology up to, but not including, Newton's Principia. Building on the advances of the Middle Ages, Kepler conceived, albeit in rudimentary form, the fundamental physical ideas of mass, "inertia," and gravitational "mutual attraction." These splendid concepts were later developed and carried forward into Newton's era by several 17th-century natural philosophers. Unlike his three planetary laws, Kepler's physics has long gone unappreciated by the scientific community. Nonetheless, it formed the conceptual foundation for much of classical dynamics.

  11. Non-adiabatic study of the Kepler subgiant KIC 6442183

    Directory of Open Access Journals (Sweden)

    Grosjean M.

    2015-01-01

    Full Text Available Thanks to the precision of Kepler observations, [3] were able to measure the linewidth and amplitude of individual modes (including mixed modes in several subgiant power spectra. We perform a forward modelling of a Kepler subgiant based on surface properties and observed frequencies. Non-adiabatic computations including a time- dependent treatment of convection give the lifetimes of radial and non-radial modes. Next, combining the lifetimes and inertias with a stochastic excitation model gives the amplitudes of the modes. We can now directly compare theoretical and observed linewidths and amplitudes of mixed-modes to obtain new constraints on our theoretical models.

  12. Evidence for compact binary systems around Kepler red giants

    DEFF Research Database (Denmark)

    Colman, Isabel L.; Huber, Daniel; Bedding, Timothy R.

    2017-01-01

    We present an analysis of 168 oscillating red giants from NASA's Kepler mission that exhibit anomalous peaks in their Fourier amplitude spectra. These peaks result from ellipsoidal variations that are indicative of binary star systems, at frequencies such that the orbit of any stellar companion...... in the sample as chance alignments using a combination of pixel Fourier analysis and difference imaging. We find that in the remaining 81 cases, the anomalous peaks are indistinguishable from the target star to within 4 arcsec, suggesting a physical association. We examine a GALAXIA model of the Kepler field...

  13. Modern scleral lenses part I: clinical features.

    Science.gov (United States)

    Visser, Esther-Simone; Visser, Rients; van Lier, Henk J J; Otten, Henny M

    2007-01-01

    To evaluate the indications for modern scleral lenses and their clinical performance in patients who were fitted with scleral lenses at the authors' practices. In this cross-sectional survey, all the necessary data were obtained at the first follow-up visit during the 5-month study period. There were four types of scleral lenses: spherical, front-surface toric, back-surface toric, and bitoric. The preformed scleral lens fitting technique developed at Visser Contact Lens Practice was used in all patients. The lenses were cut by precise Sub Micron Lathing from a Boston Equalens II blank at Procornea. Visual acuity and slitlamp findings were recorded. A specially designed classification for scleral lens fitting was used to investigate clinical performance. The largest proportion of the 178 patients (284 eyes) were diagnosed with keratoconus (143 [50.4%] eyes) followed by postpenetrating keratoplasty (56 [19.7%] eyes). The remaining diagnoses were irregular astigmatism, keratitis sicca, corneal dystrophy, and multiple diagnoses. The ratio of spherical to back-surface toric designs was 1:1.1. Clinical examination showed sharp increases in visual acuity (median increase, 0.45) and safe physiologic responses of the anterior eye. All the patients could continue to wear scleral lenses, with 79.2% with the same lens parameters. Several types of corneal abnormality were managed successfully with modern scleral lenses. The main indication was optical correction of an irregular corneal surface. Satisfactory clinical performance meant that all the patients could continue to wear their scleral lenses.

  14. Investigations of Galaxy Clusters Using Gravitational Lensing

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Matthew P. [Northern Illinois Univ., DeKalb, IL (United States)

    2014-08-01

    In this dissertation, we discuss the properties of galaxy clusters that have been determined using strong and weak gravitational lensing. A galaxy cluster is a collection of galaxies that are bound together by the force of gravity, while gravitational lensing is the bending of light by gravity. Strong lensing is the formation of arcs or rings of light surrounding clusters and weak lensing is a change in the apparent shapes of many galaxies. In this work we examine the properties of several samples of galaxy clusters using gravitational lensing. In Chapter 1 we introduce astrophysical theory of galaxy clusters and gravitational lensing. In Chapter 2 we examine evidence from our data that galaxy clusters are more concentrated than cosmology would predict. In Chapter 3 we investigate whether our assumptions about the number of galaxies in our clusters was valid by examining new data. In Chapter 4 we describe a determination of a relationship between mass and number of galaxies in a cluster at higher redshift than has been found before. In Chapter 5 we describe a model of the mass distribution in one of the ten lensing systems discovered by our group at Fermilab. Finally in Chapter 6 we summarize our conclusions.

  15. SOPHIE velocimetry of Kepler transit candidates: a joint photometric, spectroscopic and dynamical analysis of the Kepler-117 system

    Directory of Open Access Journals (Sweden)

    Bruno G.

    2015-01-01

    Full Text Available We present the analysis of the multi-planetary system Kepler-117, which is part of our program of observations of Kepler planets. This system is composed of a ~ 30 MEarth planet in a ~ 19 days orbit and a ~ 2 MJ planet orbiting in ~ 51 days. Both the orbits have low eccentricity. The planets are not close to an exact low-order mean motion resonance, but exhibit significant transit timing variations (TTVs nevertheless. We perform a combined Markov Chain Monte Carlo fit on all the available data: the Kepler photometry, the TTVs, the radial velocities we obtained with SOPHIE/OHP and the stellar parameters. The prime result is that the modelling of the TTVs allows to increase the precision on the system parameters which are not constrained by the radial velocities alone.

  16. Modern scleral lenses: Mini versus large.

    Science.gov (United States)

    Fadel, Daddi

    2017-08-01

    The evolution of scleral lenses has led to new formulations of scleral fitting concepts and designs. The diameters of modern scleral lenses have been overhauled too and they are smaller comparing to the original ones. Nowadays, prescription of mini-sclerals supposedly seems in major extension and it appears indeed the necessity of some practitioner to differentiate the smaller mini-scleral lenses from larger mini-scleral lenses empathizing that they are the "smaller" ones. Therefore, it is maybe, necessary a definition of mini-scleral lenses referring to the landing zone width in relation to the horizontal visible iris diameter (HVID) and the limbus extension. The choice of the total diameter is crucial for a successful fitting and it depends majorly on patient's topographic patterns and anatomic factors. However, there are other important criteria for the selection of the scleral lens diameter based on oxygen supply, bubbles formation, mechanical stress on a toric sclera, ocular surface disease protection, entity of the vault over the cornea and distribution of the lens weight on the sclera. The advantages of mini-scleral lenses are various nonetheless in some cases large lenses are necessary. This paper presents a review of the benefits and disadvantages of both mini and large scleral lenses analyzing the conditions in which it may be better to prefer one diameter to another. A suggestion may be that to start fitting the smallest lens as possible, depending on the dimension of HVID and limbus width and consider larger lenses only when issues occur. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  17. 'Colored' and Decorative Contact Lenses: A Prescription Is a Must

    Science.gov (United States)

    ... these looks with decorative contact lenses (sometimes called “fashion,” “costume,” or “colored” contact lenses). These lenses don’ ... Wear Decorative or “Colored” Contact Lenses An entertainment industry artist from American Horror Story and the FDA ...

  18. Nanofocusing refractive X-ray lenses

    International Nuclear Information System (INIS)

    Boye, Pit

    2010-01-01

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  19. Nanofocusing refractive X-ray lenses

    Energy Technology Data Exchange (ETDEWEB)

    Boye, Pit

    2010-02-05

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  20. Tevatron Electron Lenses: Design and Operation

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; /Fermilab; Bishofberger, Kip; /Los Alamos; Kamerdzhiev, Vsevolod; /Fermilab; Kozub, Sergei; /Serpukhov, IHEP; Kufer, Matthew; Kuznetsov, Gennady; Martinez, Alexander; Olson, Marvin; Pfeffer, Howard; Saewert, Greg; Scarpine, Vic; /Fermilab /SLAC /Fermilab /Serpukhov, IHEP /Novosibirsk, IYF /Serpukhov, IHEP /Fermilab

    2008-08-01

    The beam-beam effects have been the dominating sources of beam loss and lifetime limitations in the Tevatron proton-antiproton collider [1]. Electron lenses were originally proposed for compensation of electromagnetic long-range and head-on beam-beam interactions of proton and antiproton beams [2]. Results of successful employment of two electron lenses built and installed in the Tevatron are reported in [3,4,5]. In this paper we present design features of the Tevatron electron lenses (TELs), discuss the generation of electron beams, describe different modes of operation and outline the technical parameters of various subsystems.

  1. Thin Film Coating Technology For Ophthalmic Lenses

    Science.gov (United States)

    Guenther, K. H.

    1986-05-01

    Coating of ophthalmic lenses is an application of high-vacuum coating technology which must satisfy not only physical and technical requirements but also customer demands with respect to aesthetics, color fidelity, and exchangeability of coated ophthalmic lenses. Because this application caters specifically to the consumer market, ophthalmic lenses are subject to certain fashion trends which frequently require quick adaptation of the coating technique. The state-of-the-art of ophthalmic lens coating is reviewed in this paper, with particular emphasis on the durability requirements in daily use by untrained consumers as well as on the applicable testing methods.

  2. Cosmological applications of strong gravitational lensing

    DEFF Research Database (Denmark)

    Paraficz, Danuta

    value of the energy density of the two above components, together with measuring the Hubble constant that determines the age of the Universe, is a major goal of modern astrophysics. An interesting method for estimating these parameters is strong gravitational lensing of quasars (QSOs). As shown...... by Refsdal (1964), H0, !m and !! can be measured based on the time delay ("t) between multiply lensed images of QSOs, because "t depends on H0 and on the distances to lens and source, hence!m and !!. Determination of cosmological parameters using gravitational lensing suffers from some degeneracies......, but it is based on well understood physics and unlike distance ladder methods there are no calibration issues. Moreover, it has an advantage over some of the leading methods (such as Type Ia SNe) in that it is a purely cosmological approach. In this thesis, the property of strong gravitational lensing - time...

  3. Characterisation of adaptive fluidic silicone membrane lenses

    CSIR Research Space (South Africa)

    Schneider, F

    2009-09-01

    Full Text Available In this paper the auhtors compare the performance and optical quality of two types of adaptive fluidic silicone-membrane lenses. The membranes feature either a homogeneous thickness, or they are shaped resulting in an inhomogeneous cross...

  4. Disposable contact lenses in penetrating keratoplasty.

    Science.gov (United States)

    Arora, R; Gupta, S; Taneja, M; Raina, U K; Mehta, D K

    2000-07-01

    To evaluate the therapeutic efficacy of disposable contact lenses in management of complications after keratoplasty. Twenty-eight patients with various post keratoplasty complications were fit with disposable contact lenses (45% Vifilcon A and 55% water content). Indications for lens use included persistent epithelial defects, wound leak, graft edema, dry eye and protection of normal corneal epithelium. Success was obtained with the therapeutic use of disposable lenses in 20 of the 28 cases. The best results were seen in maintenance and restoration of healthy ocular surface and small wound leaks. Stromal graft edema with no epithelial involvement was the major area of therapeutic failure. Disposable contact lenses are an attractive low cost option in the management of complications after keratoplasty. They are particularly useful in maintaining a healthy ocular surface, providing symptomatic relief and avoiding resurgery in patients with small wound leaks.

  5. Gravitational Lensing Mass Mapping with Gaussian Processes

    Science.gov (United States)

    Schneider, Michael; Ng, Karen; Dawson, William; Marshall, Phil; Meyers, Joshua; Bard, Deborah

    2018-01-01

    We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a Gaussian Process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed cosmological lensing shear maps and a reconstruction of the mass distribution of the merging galaxy cluster Abell 781 using galaxy ellipticities measured with the Deep Lens Survey. Given interim posterior samples of lensing shear or convergence fields on the sky, we describe an algorithm to infer cosmological parameters via lens field marginalization. In the most general formulation of our algorithm we make no assumptions about weak shear orGaussian-distributed shape noise or shears. Because we require solutions and matrix determinants of a linear system of dimension that scales with the number of galaxies, we present computational performance metrics with approximate algorithms that introduce sparsity in the Gaussian Process kernel.

  6. Student Ideas about Kepler's Laws and Planetary Orbital Motions

    Science.gov (United States)

    Yu, Ka Chun; Sahami, Kamran; Denn, Grant

    2010-01-01

    We present the analysis of oral interviews with 112 undergraduate nonmajor students during the first week of a General Education Introduction to Astronomy class before they had received any instruction. The students were asked questions relating to Kepler's three Laws of Motion, as well as their understanding of what keeps planets in orbit around…

  7. Dynamical investigation of modulated Kepler RR Lyrae stars

    Directory of Open Access Journals (Sweden)

    Plachy E.

    2015-01-01

    Full Text Available We performed a non-linear dynamical analysis on the Blazhko modulation for the first time. Our results suggest that the detection of chaotic nature behind the phenomenon is limited by the instrumental effects and the data processing problems of the Kepler pipeline concerning high-amplitude variable stars.

  8. Kepler and the Physics of the Heavenly Bodies

    Indian Academy of Sciences (India)

    Admin

    The year 1609 was also notable for the publication of yet another book Commentaries on the. Motions of Mars. It was the outcome of two decades of hard work by Kepler. He had at his disposal the most accurate observational data of those times. The task of fitting the right type of orbit to the planets' motion kept him engaged ...

  9. Acoustic glitches in solar-type stars from Kepler

    DEFF Research Database (Denmark)

    Mazumdar, A.; Monteiro, M. J. P. F. G.; Ballot, J

    2012-01-01

    We report the measurement of the acoustic locations of layers of sharp variation in sound speed in the interiors of 19 solar-type stars observed by the Kepler mission. The oscillatory signal in the frequencies arising due to the acoustic glitches at the base of the convection zone and the second...... with representative models of the stars....

  10. A Simple Derivation of Kepler's Laws without Solving Differential Equations

    Science.gov (United States)

    Provost, J.-P.; Bracco, C.

    2009-01-01

    Proceeding like Newton with a discrete time approach of motion and a geometrical representation of velocity and acceleration, we obtain Kepler's laws without solving differential equations. The difficult part of Newton's work, when it calls for non-trivial properties of ellipses, is avoided by the introduction of polar coordinates. Then a simple…

  11. Eta-Sub-Earth Projection from Kepler Data

    Science.gov (United States)

    Traub, Wesley A.

    2012-01-01

    Outline of talk: (1) The Kepler database (2) Biases (3) The radius distribution (4) The period distribution (5) Projecting from the sam ple to the population (6) Extrapolating the period distribution (7) The Habitable Zone (8) Calculating the number of terrestrial, HZ plan ets (10) Conclusions

  12. Five kepler target stars that show multiple transiting exoplanet candidates

    DEFF Research Database (Denmark)

    Steffen..[], Jason H.; Batalha, N. M.; Broucki, W J.

    2010-01-01

    We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets...

  13. A history of astronomy from Thales to Kepler

    CERN Document Server

    Dreyer, J L E

    1953-01-01

    A masterpiece of historical insight and scientific accuracy, this is the definitive work on Greek astronomy and the Copernican Revolution. Beginning with the ancient Egyptians, it ranges from the Pythagoreans and Plato to medieval European and Islamic cosmologies, concluding with detailed surveys of the works of Copernicus, Brahe, and Kepler.

  14. Kepler-7b: A Transiting Planet With Unusually Low Density

    Science.gov (United States)

    2010-04-20

    and surface gravity of Teff = 5944 K and log g = 4.27 (cgs) to Kepler-7, corresponding to a late-F or early-G dwarf . Stellar gravities in this part of...Kurucz, R. L. 1992, in IAU Symp. 149, The Stellar Populations of Galaxies , ed. B. Barbuy & A. Renzini (Dordrecht: Kluwer), 225 Monet, D. G., et al. 2010

  15. Stability of the Kepler-11 system and its origin

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, Nikhil; Wu, Yanqin [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

    2014-11-01

    A significant fraction of Kepler systems are closely packed, largely coplanar, and circular. We study the stability of a six-planet system, Kepler-11, to gain insights on the dynamics and formation history of such systems. Using a technique called 'frequency maps' as fast indicators of long-term stability, we explore the stability of the Kepler-11 system by analyzing the neighborhood space around its orbital parameters. Frequency maps provide a visual representation of chaos and stability, and their dependence on orbital parameters. We find that the current system is stable, but lies within a few percent of several dynamically dangerous two-body mean-motion resonances. Planet eccentricities are restricted below a small value, ∼0.04, for long-term stability, but planet masses can be more than twice their reported values (thus allowing for the possibility of mass loss by past photoevaporation). Based on our frequency maps, we speculate on the origin of instability in closely packed systems. We then proceed to investigate how the system could have been assembled. The stability constraints on Kepler-11 (mainly eccentricity constraints) suggest that if the system were assembled in situ, a dissipation mechanism must have been at work to neutralize the eccentricity excitation. On the other hand, if migration was responsible for assembling the planets, there has to be little differential migration among the planets to avoid them either getting trapped into mean motion resonances, or crashing into each other.

  16. A POTENTIAL SUPER-VENUS IN THE KEPLER-69 SYSTEM

    International Nuclear Information System (INIS)

    Kane, Stephen R.; Gelino, Dawn M.; Barclay, Thomas

    2013-01-01

    Transiting planets have greatly expanded and diversified the exoplanet field. These planets provide greater access to characterization of exoplanet atmospheres and structure. The Kepler mission has been particularly successful in expanding the exoplanet inventory, even to planets smaller than the Earth. The orbital period sensitivity of the Kepler data is now extending into the habitable zones of their host stars, and several planets larger than the Earth have been found to lie therein. Here we examine one such proposed planet, Kepler-69c. We provide new orbital parameters for this planet and an in-depth analysis of the habitable zone. We find that, even under optimistic conditions, this 1.7 R ⊕ planet is unlikely to be within the habitable zone of Kepler-69. Furthermore, the planet receives an incident flux of 1.91 times the solar constant, which is similar to that received by Venus. We thus suggest that this planet is likely a super-Venus rather than a super-Earth in terms of atmospheric properties and habitability, and we propose follow-up observations to disentangle the ambiguity.

  17. Characterization of red giant stars in the public Kepler data

    NARCIS (Netherlands)

    Hekker, S.; Gilliland, R.L.; Elsworth, Y.; Chaplin, W.J.; de Ridder, J.; Stello, D.; Kallinger, T.; Ibrahim, K.A.; Klaus, T.C.; Li, J.

    2011-01-01

    The first public release of long-cadence stellar photometric data collected by the NASA Kepler mission has now been made available. In this paper, we characterize the red giant (G-K) stars in this large sample in terms of their solar-like oscillations. We use published methods and well-known scaling

  18. Verifying asteroseismically determined parameters of Kepler stars using Hipparcos parallaxes

    DEFF Research Database (Denmark)

    Aguirre, Victor Silva; Chaplin, W.J.; Bedding, T.R.

    2012-01-01

    observables and multi-band photometry, the technique allows us to obtain masses, radii, effective temperatures, bolometric fluxes, and hence distances for field stars in a self-consistent manner. We apply our method to 22 solar-like oscillators in the Kepler short-cadence sample, that have accurate Hipparcos...

  19. Preparation of Kepler light curves for asteroseismic analyses

    NARCIS (Netherlands)

    García, R.A.; Hekker, S.; Stello, D.; Gutiérrez-Soto, J.; Handberg, R.; Huber, D.; Karoff, C.; Uytterhoeven, K.; Appourchaux, T.; Chaplin, W.J.; Elsworth, Y.; Mathur, S.; Ballot, J.; Christensen-Dalsgaard, J.; Gilliland, R.L.; Houdek, G.; Jenkins, J.M.; Kjeldsen, H.; McCauliff, S.; Metcalfe, T.; Middour, C.K.; Molenda-Zakowicz, J.; Monteiro, M.J.P.F.G.; Smith, J.C.; Thompson, M.J.

    2011-01-01

    The Kepler mission is providing photometric data of exquisite quality for the asteroseismic study of different classes of pulsating stars. These analyses place particular demands on the pre-processing of the data, over a range of time-scales from minutes to months. Here, we describe processing

  20. Kepler observations of the variability in B-type stars

    DEFF Research Database (Denmark)

    Balona, Luis A.; Pigulski, A.; De Cat, P.

    2011-01-01

    The analysis of the light curves of 48 B-type stars observed by Kepler is presented. Among these are 15 pulsating stars, all of which show low frequencies, characteristic of slowly pulsating B (SPB) stars. Seven of these stars also show a few weak, isolated high frequencies and they could...

  1. Kepler and the Physics of the Heavenly Bodies

    Indian Academy of Sciences (India)

    Admin

    should have 2, Jupiter has 4, Saturn should have 8 and so on). Since no satellites were known for Mars (and Saturn), all the other ideas in his books too were probably shelved. Very few, like the well-known author Jonathan Swift, admired Kepler. Swift used the idea of two satellites of. Mars in his book Gulliver's Travels ...

  2. Thirty Meter Telescopes and Gravitational Lensing

    OpenAIRE

    Carlberg, R. G.

    2004-01-01

    Diffraction limited 30m class telescopes will play an important role in gravitational lensing studies, coming online in approximately 2015. As imaging telescopes they will complement the ~6m JWST, probing to smaller angular scales in greatly magnified objects near critical lines and for measuring shear of objects below the JWST angular scale, such as luminous super-star clusters at high redshift. The high source density will allow more detailed mass mapping in the weak lensing regime and will...

  3. Comments on the Gravitational lensing Magnification

    OpenAIRE

    Takashi, HAMANA; Astronomical Institute, Tohoku University

    1998-01-01

    We rederive a relation between gravitational lensing magnification relative to the standard Friedmann distance and one relative to the Dyer-Roeder distance by investigating the null geodesic deviation equation. We show that the relation comes from a natural consequence of the definition of the lensing magnification matrices and is not based on the averaging of the magnifications, which has conventionally been used to derive it. We therefore conclude that the relation is true for each individu...

  4. Comments on the gravitational lensing magnification

    OpenAIRE

    Hamana, Takashi

    1998-01-01

    We rederive a relation between gravitational lensing magnification relative to the standard Friedmann distance and one relative to the Dyer-Roeder distance by investigating the null geodesic deviation equation. We show that the relation comes from a natural consequence of the definition of the lensing magnification matrices and is not based on the averaging of the magnifications, which has conventionally been used to derive it. We therefore conclude that the relation is true for each individu...

  5. Planck 2015 results: XV. Gravitational lensing

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.

    2016-01-01

    We present the most significant measurement of the cosmic microwave background (CMB) lensing potential to date (at a level of 40σ), using temperature and polarization data from the Planck 2015 full-mission release. Using a polarization-only estimator, we detect lensing at a significance of 5σ. We......-scale temperature anisotropies, detecting a cross-correlation at the 3σ level, as expected because of dark energy in the concordance ΛCDM model....

  6. Electron Lenses for particle collimation in LHC

    CERN Document Server

    Shiltsev, V

    2008-01-01

    Electron Lenses built and installed in Tevatron have proven themselves as safe and very reliable instruments which can be effectively used in hadron collider operation for a number of applications, including compensation of beam-beam effects , DC beam removal from abort gaps , as a diagnostic tool. In this presentation we – following original proposal – consider in more detail a possibility of using electron lenses with hollow electron beam for ion and proton collimation in LHC.

  7. Revised Unfilling Procedure for Solid Lithium Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Leveling, A.; /Fermilab

    2003-06-03

    A procedure for unfilling used lithium lenses to has been described in Pbar Note 664. To date, the procedure has been used to disassemble lenses 20, 21, 17, 18, and 16. As a result of this work, some parts of the original procedure were found to be time consuming and ineffective. Modifications to the original procedure have been made to streamline the process and are discussed in this note. The revised procedure is included in this note.

  8. Postpartum Care Services and Birth Features of The Women Who Gave Birth in Burdur in 2009

    Directory of Open Access Journals (Sweden)

    Binali Catak

    2011-10-01

    Full Text Available AIM: In the study, it is aimed to evaluate postpartum care services and the delivery characteristics of the women who gave birth in Burdur in 2009. MATERIAL AND METHODS: In the study, the data is used about \\\\\\"Birth and Postpartum Care\\\\\\" of the research \\\\\\" Birth, Postpartum Care Services, and Nutritional Status of Children of the women who are giving birth in Burdur in 2009 \\\\\\". The population of the planned cross-sectional study are women who gave birth in Burdur in 2009. For the determination of the population, a list of women who gave birth in 2009 were used which was requested from family physicians. The reported number of women was 2318. The sample size representing the population to be reached was calculated as 1179. The data were collected using face-to-face interviews and were analyzed using SPSS package program. RESULTS: The mean age of the women was 27.1 (± 5.5 with an average size of households 4.3 (± 1.2. 22.1% of the women live with large families and 64.4% live in the village. 8.0% of the women were relatives with their husbands, 52.8% have arranged marriage and 1.3% have no official marriage. 1 in every 4 women is housewive, 1.8% have no formal education, 76.4% have no available social and 7.1% have no available health insurance. The average number of pregnancies of women is 2.1 (± 1.2 and number of children is 1.8 (± 0.8. Spontaneous abortion, induced abortion, stillbirth and death rate of children under 5 years of age are respectively 16.4%, 6.6%, 2.7%, 3.4%. 99.8% of the women have given birth in hospital, % 67.3 had medical supervision, 62.8% had cesarean birth. The average days of hospital stay after birth is 1.9 (± 3.1. 4.8% of the women after being discharged from the hospital have not received Postpartum Care (DSB. Of the women who have received DSB service, 2.2% had taken this service at home by family physician / family health stuff, 33.9% by obstetrician in practice. 92.2% of the women 1 time, 15

  9. Predicting gravitational lensing by stellar remnants

    Science.gov (United States)

    Harding, Alexander J.; Stefano, R. Di; Lépine, S.; Urama, J.; Pham, D.; Baker, C.

    2018-03-01

    Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper, we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, five black holes, and ≈35 000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here, we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With Hubble Space Telescope, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets.

  10. MARVELS Radial Velocity Solutions to Seven Kepler Eclipsing Binaries

    Science.gov (United States)

    Heslar, Michael Francis; Thomas, Neil B.; Ge, Jian; Ma, Bo; Herczeg, Alec; Reyes, Alan; SDSS-III MARVELS Team

    2016-01-01

    Eclipsing binaries serve momentous purposes to improve the basis of understanding aspects of stellar astrophysics, such as the accurate calculation of the physical parameters of stars and the enigmatic mass-radius relationship of M and K dwarfs. We report the investigation results of 7 eclipsing binary candidates, initially identified by the Kepler mission, overlapped with the radial velocity observations from the SDSS-III Multi-Object APO Radial-Velocity Exoplanet Large-Area Survey (MARVELS). The RV extractions and spectroscopic solutions of these eclipsing binaries were generated by the University of Florida's 1D data pipeline with a median RV precision of ~60-100 m/s, which was utilized for the DR12 data release. We performed the cross-reference fitting of the MARVELS RV data and the Kepler photometric fluxes obtained from the Kepler Eclipsing Binary Catalog (V2) and modelled the 7 eclipsing binaries in the BinaryMaker3 and PHOEBE programs. This analysis accurately determined the absolute physical and orbital parameters of each binary. Most of the companion stars were determined to have masses of K and M dwarf stars (0.3-0.8 M⊙), and allowed for an investigation into the mass-radius relationship of M and K dwarfs. Among the cases are KIC 9163796, a 122.2 day period "heartbeat star", a recently-discovered class of eccentric binaries known for tidal distortions and pulsations, with a high eccentricity (e~0.75) and KIC 11244501, a 0.29 day period, contact binary with a double-lined spectrum and mass ratio (q~0.45). We also report on the possible reclassification of 2 Kepler eclipsing binary candidates as background eclipsing binaries based on the analysis of the flux measurements, flux ratios of the spectroscopic and photometric solutions, the differences in the FOVs, the image processing of Kepler, and RV and spectral analysis of MARVELS.

  11. PLANET HUNTERS: ASSESSING THE KEPLER INVENTORY OF SHORT-PERIOD PLANETS

    International Nuclear Information System (INIS)

    Schwamb, Megan E.; Lintott, Chris J.; Lynn, Stuart; Smith, Arfon M.; Simpson, Robert J.; Fischer, Debra A.; Giguere, Matthew J.; Brewer, John M.; Parrish, Michael; Schawinski, Kevin

    2012-01-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of ≥2 R ⊕ planets on short-period ( ⊕ Planet Hunters ≥85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler ≥4 R ⊕ planets suggests that the Kepler inventory of ≥4 R ⊕ short-period planets is nearly complete.

  12. Gravitationally Lensed Quasars in Gaia: II. Discovery of 24 Lensed Quasars

    Science.gov (United States)

    Lemon, Cameron A.; Auger, Matthew W.; McMahon, Richard G.; Ostrovski, Fernanda

    2018-04-01

    We report the discovery, spectroscopic confirmation and preliminary characterisation of 24 gravitationally lensed quasars identified using Gaia observations. Candidates were selected in the Pan-STARRS footprint with quasar-like WISE colours or as photometric quasars from SDSS, requiring either multiple detections in Gaia or a single Gaia detection near a morphological galaxy. The Pan-STARRS grizY images were modelled for the most promising candidates and 60 candidate systems were followed up with the William Herschel Telescope. 13 of the lenses were discovered as Gaia multiples and 10 as single Gaia detections near galaxies. We also discover 1 lens identified through a quasar emission line in an SDSS galaxy spectrum. The lenses have median image separation 2.13″ and the source redshifts range from 1.06 to 3.36. 4 systems are quadruply-imaged and 20 are doubly-imaged. Deep CFHT data reveal an Einstein ring in one double system. We also report 12 quasar pairs, 10 of which have components at the same redshift and require further follow-up to rule out the lensing hypothesis. We compare the properties of these lenses and other known lenses recovered by our search method to a complete sample of simulated lenses to show the lenses we are missing are mainly those with small separations and higher source redshifts. The initial Gaia data release only catalogues all images of ˜ 30% of known bright lensed quasars, however the improved completeness of Gaia data release 2 will help find all bright lensed quasars on the sky.

  13. Relative radiosensitivity of rat lenses as a function of age

    International Nuclear Information System (INIS)

    Merriam, G.R. Jr.; Szechter, A.

    1975-01-01

    The effect of age on the development of radiation cataracts in rat lenses has been investigated using the Columbia--Sherman rat as an experiment model. A detailed pattern of age dependence was obtained at several different dose levels. In general at dose levels from 200 to 300 rads the lens changes occurred sooner and progressed faster in the adult lenses than in young lenses. In the dose range from 300 rads to 900 rads opacities developed sooner in the young lenses but progression was faster and severe opacities developed sooner in adult lenses. Above 900 rads opacities developed sooner and progressed faster in the young lenses. (U.S.)

  14. Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler

    DEFF Research Database (Denmark)

    Howard, Andrew W.; Marcy, Geoffrey W.; Bryson, Stephen T.

    2012-01-01

    We report the distribution of planets as a function of planet radius, orbital period, and stellar effective temperature for orbital periods less than 50 days around solar-type (GK) stars. These results are based on the 1235 planets (formally "planet candidates") from the Kepler mission that include...... of transit, R /a. We consider first Kepler target stars within the "solar subset" having T eff = 4100-6100 K, log g = 4.0-4.9, and Kepler magnitude Kp

  15. TransitSOM: Self-Organizing Map for Kepler and K2 transits

    Science.gov (United States)

    Armstrong, D. J.; Pollacco, D.; Santerne, A.

    2017-03-01

    A self-organizing map (SOM) can be used to identify planetary candidates from Kepler and K2 datasets with accuracies near 90% in distinguishing known Kepler planets from false positives. TransitSOM classifies a Kepler or K2 lightcurve using a self-organizing map (SOM) created and pre-trained using PyMVPA (ascl:1703.009). It includes functions for users to create their own SOMs.

  16. DESIGN OF THE MULTIORDER INTRAOCULAR LENSES

    Directory of Open Access Journals (Sweden)

    V. G. Kolobrodov

    2015-01-01

    Full Text Available Intraocular lenses (IOLs are used to replace the natural crystalline lens of the eye. Just few basic designs of IOLs are used clinically. Multiorder diffractive lenses (MODL which operate simultaneously in several diffractive orders were proposed to decrease the chromatic aberration. Properties analysis of MODL showed a possibility to use them to develop new designs of IOLs. The purpose of this paper was to develop a new method of designing of multiorder intraocular lenses with decreased chromatic aberration. The theoretical research of the lens properties was carried out. The diffraction efficiency dependence with the change of wavelength was studied. A computer simulation of MODL in a schematic model of the human eye was carried out. It is found the capability of the multiorder diffractive lenses to focus polychromatic light into a segment on the optical axis with high diffraction efficiency. At each point of the segment is present each component of the spectral range, which will build a color image in combination. The paper describes the new design method of intraocular lenses with reduced chromaticism and with endless adaptation. An optical system of an eye with an intraocular lens that provides sharp vision of objects located at a distance of 700 mm to infinity is modeled.

  17. Modern scleral contact lenses: A review.

    Science.gov (United States)

    van der Worp, Eef; Bornman, Dina; Ferreira, Daniela Lopes; Faria-Ribeiro, Miguel; Garcia-Porta, Nery; González-Meijome, José M

    2014-08-01

    Scleral contact lenses (ScCL) have gained renewed interest during the last decade. Originally, they were primarily used for severely compromised eyes. Corneal ectasia and exposure conditions were the primary indications. However, the indication range of ScCL in contact lens practices seems to be expanding, and it now increasingly includes less severe and even non-compromised eyes, too. All lenses that partly or entirely rest on the sclera are included under the name ScCL in this paper; although the Scleral Lens Education Society recommends further classification. When a lens partly rests on the cornea (centrally or peripherally) and partly on the sclera, it is called a corneo-scleral lens. A lens that rests entirely on the sclera is classified as a scleral lens (up to 25 mm in diameter maximum). When there is full bearing on the sclera, further distinctions of the scleral lens group include mini-scleral and large-scleral lenses. This manuscript presents a review of the current applications of different ScCL (all types), their fitting methods, and their clinical outcomes including potential adverse events. Adverse events with these lenses are rare, but the clinician needs to be aware of them to avoid further damage in eyes that often are already compromised. The use of scleral lenses for non-pathological eyes is discussed in this paper. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  18. CMB-lensing beyond the Born approximation

    International Nuclear Information System (INIS)

    Marozzi, Giovanni; Fanizza, Giuseppe; Durrer, Ruth; Dio, Enea Di

    2016-01-01

    We investigate the weak lensing corrections to the cosmic microwave background temperature anisotropies considering effects beyond the Born approximation. To this aim, we use the small deflection angle approximation, to connect the lensed and unlensed power spectra, via expressions for the deflection angles up to third order in the gravitational potential. While the small deflection angle approximation has the drawback to be reliable only for multipoles ℓ ∼< 2500, it allows us to consistently take into account the non-Gaussian nature of cosmological perturbation theory beyond the linear level. The contribution to the lensed temperature power spectrum coming from the non-Gaussian nature of the deflection angle at higher order is a new effect which has not been taken into account in the literature so far. It turns out to be the leading contribution among the post-Born lensing corrections. On the other hand, the effect is smaller than corrections coming from non-linearities in the matter power spectrum, and its imprint on CMB lensing is too small to be seen in present experiments.

  19. Plasma lenses for focusing relativistic electron beams

    International Nuclear Information System (INIS)

    Govil, R.; Wheeler, S.; Leemans, W.

    1997-01-01

    The next generation of colliders require tightly focused beams with high luminosity. To focus charged particle beams for such applications, a plasma focusing scheme has been proposed. Plasma lenses can be overdense (plasma density, n p much greater than electron beam density, n b ) or underdense (n p less than 2 n b ). In overdense lenses the space-charge force of the electron beam is canceled by the plasma and the remaining magnetic force causes the electron beam to self-pinch. The focusing gradient is nonlinear, resulting in spherical aberrations. In underdense lenses, the self-forces of the electron beam cancel, allowing the plasma ions to focus the beam. Although for a given beam density, a uniform underdense lens produces smaller focusing gradients than an overdense lens, it produces better beam quality since the focusing is done by plasma ions. The underdense lens can be improved by tapering the density of the plasma for optimal focusing. The underdense lens performance can be enhanced further by producing adiabatic plasma lenses to avoid the Oide limit on spot size due to synchrotron radiation by the electron beam. The plasma lens experiment at the Beam Test Facility (BTF) is designed to study the properties of plasma lenses in both overdense and underdense regimes. In particular, important issues such as electron beam matching, time response of the lens, lens aberrations and shot-to-shot reproducibility are being investigated

  20. Asteroseismology of solar-type stars with Kepler: III. Ground-based data

    DEFF Research Database (Denmark)

    Karoff, Christoffer; Molenda-Żakowicz , J.

    2010-01-01

    We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler Asteroseis......We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler...

  1. Limits On Undetected Planets in the Six Transiting Planets Kepler-11 System

    Science.gov (United States)

    Lissauer, Jack

    2017-01-01

    The Kepler-11 has five inner planets ranging from approx. 2 - 1 times as massive Earth in a tightly-packed configuration, with orbital periods between 10 and 47 days. A sixth planet, Kepler-11 g, with a period of118 days, is also observed. The spacing between planets Kepler-11 f and Kepler-11 g is wide enough to allow room for a planet to orbit stably between them. We compare six and seven planet fits to measured transit timing variations (TTVs) of the six known planets. We find that in most cases an additional planet between Kepler-11 f and Kepler-11 g degrades rather than enhances the fit to the TTV data, and where the fit is improved, the improvement provides no significant evidence of a planet between Kepler-11 f and Kepler-11 g. This implies that any planet in this region must be low in mass. We also provide constraints on undiscovered planets orbiting exterior to Kepler-11 g. representations will be described.

  2. Trojan Asteroids in the Kepler Campaign 6 Field

    Science.gov (United States)

    Ryan, Erin Lee; Sharkey, Benjamin N. L.; Woodward, Charles E.

    2017-03-01

    We report on a Kepler spacecraft survey during the K2 mission to characterize the rotational properties of 56 Trojan asteroids in the L4 cloud. More than one rotational period was observed for 51 of these targets, allowing for well constrained lightcurve rotation periods and amplitudes, five of which are found to be in conflict with previously published values. We find ˜10% of objects have rotational periods longer than 100 hr, an excess of slow rotators 10 times larger than suggested from the literature. Investigation of the rotational frequencies of our Kepler sample when combined with high-quality lightcurves in the literature reveals the distribution of rotational frequencies is non-Maxwellian even when consideration is given to size-dependent variations in rotational rate. From investigation of lightcurve shapes and amplitudes, we estimate the binary fraction within the Trojan population to be ˜6%-36% depending on the methodology utilized to identify binary candidates.

  3. Unraveling the Internal Chemical Composition of Kepler White Dwarf Pulsators

    Science.gov (United States)

    Giammichele, N.; Charpinet, S.; Fontaine, G.; Brassard, P.

    2017-03-01

    We present the results of the asteroseismic analysis of a selected sample of white dwarf stars in the Kepler and Kepler-2 fields. Our seismic procedure using the forward method based on physically sound, static models, includes a new core parameterization leading us to reproduce the periods of these stars at the precision of the observations. These new fits outperform current state-of-the-art standards by orders of magnitude. We precisely establish the internal structures of these stars and unravel the inner C/O stratification of their core. By studying their internal chemical compositions, and more precisely the C/O profiles, this opens up interesting perspectives on better constraining key processes in stellar physics such as nuclear burning, convection, and mixing, that shape this stratification over time.

  4. "Cosmomorphistic geometry" in the unconscious geometry of Johannes Kepler

    Science.gov (United States)

    Adam, Adolf

    Some mathematical aspects of the Music theory by Johannes Kepler are discussed, paying a special attention to the book "De harmonice mundi". Other scientists interested in Music theory are mentioned throughout the paper: The Pythagorean school, Klaudios Ptolemaios, Leonard Euler, Gottfried Wilhelm Leibniz, Christian von Goldbach, Hermann Ludwig Ferdinand von Helmholz, Karl Friedrich Gauss. The relation with the ancient chinese schools of cosmography has been discussed: From the the Pythagorean to the ancient Chinese schools of cosmography we find arithmo-geometrical applications of numbers which are emblematic, hold meaning or represent the essence of things, the author writes. It was Johannes Kepler who taught us this "transconstructive method" of forming classical and ancient begginings of structuralistic thinking into a system from which deductions can readily be made.

  5. Gravitational Lensing from a Spacetime Perspective

    Directory of Open Access Journals (Sweden)

    Perlick Volker

    2004-09-01

    Full Text Available The theory of gravitational lensing is reviewed from a spacetime perspective, without quasi-Newtonian approximations. More precisely, the review covers all aspects of gravitational lensing where light propagation is described in terms of lightlike geodesics of a metric of Lorentzian signature. It includes the basic equations and the relevant techniques for calculating the position, the shape, and the brightness of images in an arbitrary general-relativistic spacetime. It also includes general theorems on the classification of caustics, on criteria for multiple imaging, and on the possible number of images. The general results are illustrated with examples of spacetimes where the lensing features can be explicitly calculated, including the Schwarzschild spacetime, the Kerr spacetime, the spacetime of a straight string, plane gravitational waves, and others.

  6. Cosmological applications of strong gravitational lensing

    DEFF Research Database (Denmark)

    Paraficz, Danuta

    value of the energy density of the two above components, together with measuring the Hubble constant that determines the age of the Universe, is a major goal of modern astrophysics. An interesting method for estimating these parameters is strong gravitational lensing of quasars (QSOs). As shown......One of the most intriguing recent results in physics is the growing evidence that an unknown energy field and an unknown kind of matter are the major components of the Universe (70% and 30%, respectively; see e.g. Riess et al. 1998, Spergel et al. 2007). Understanding and estimating the precise...... by Refsdal (1964), H0, !m and !! can be measured based on the time delay ("t) between multiply lensed images of QSOs, because "t depends on H0 and on the distances to lens and source, hence!m and !!. Determination of cosmological parameters using gravitational lensing suffers from some degeneracies...

  7. Electron lenses for super-colliders

    CERN Document Server

    Shiltsev, Vladimir D

    2016-01-01

    This book provides a comprehensive overview of the operating principles and technology of electron lenses in supercolliders.  Electron lenses are a novel instrument for high energy particle accelerators, particularly for the energy-frontier superconducting hadron colliders, including the Tevatron, RHIC, LHC and future very large hadron colliders.  After reviewing the issues surrounding beam dynamics in supercolliders, the book offers an introduction to the electron lens method and its application.  Further chapters describe the technology behind the electron lenses which have recently been proposed, built and employed for compensation of beam-beam effects and for collimation of high-energy high-intensity beams, for compensation of space-charge effects and several other applications in accelerators. The book will be an invaluable resource for those involved in the design, construction and operation of the next generation of hadron colliders.

  8. X-ray surface brightness of Kepler's supernova remnant

    International Nuclear Information System (INIS)

    White, R.L.; Long, K.S.

    1983-01-01

    We have observed Kepler's supernova remnant (SNR) with the imaging instruments on board the Einstein Observatory. The 0.15-4.5 keV flux incident on the Earth is 1.2 x 10 - 10 ergs cm - 2 s - 1 ; the flux corrected for interstellar absorption is 3.4 x 10 - 10 ergs cm - 2 s - 1 (L/sub x/ = 1.0 x 10 36 ergs s - 1 at D = 5 kpc) if the absorbing column density is N/sub H/ = 2.8 x 10 21 cm - 2 . The remnant is circular and shows a strong shell which is at least 5 times brighter in the north than in the south. The X-ray observations do not unambiguously determine whether the remnant is in the adiabatic or the free expansion phase. If the remnant is in the adiabatic phase, the density of the interstellar medium (ISM) ( 2 /sub e/>/sup 1/2/) surrounding Kepler's SNR must be about 5 cm - 3 . If the remnant is in the free expansion phase, where most of the emission arises from shock-heated ejecta, the ISM density must still be relatively high, n/sub i/> or approx. =0.1 cm - 3 . Even if the ISM is very inhomogeneous, with very many small, dense clouds, we show that the mean density of the ISM must be greater than approx.0.1 cm - 3 . In any case, the density of the x-ray emitting gas must be high ( 2 /sub e/>/sup 1/2/ > or approx. =10 cm - 3 ), and the temperature must be fairly low (T/sub e/ 7 K). The relatively high ISM density which is required is surprising in view of Kepler's distance above the galactic plane, approx.600 pc. Possibly the ISM around Kepler's SNR and around other type i SNRs is dominated by the mass lost from the presupernova star

  9. Flare Activity of Wide Binary Stars with Kepler

    Science.gov (United States)

    Clarke, Riley W.; Davenport, James R. A.; Covey, Kevin R.; Baranec, Christoph

    2018-01-01

    We present an analysis of flare activity in wide binary stars using a combination of value-added data sets from the NASA Kepler mission. The target list contains a set of previously discovered wide binary star systems identified by proper motions in the Kepler field. We cross-matched these systems with estimates of flare activity for ∼200,000 stars in the Kepler field, allowing us to compare relative flare luminosity between stars in coeval binaries. From a sample of 184 previously known wide binaries in the Kepler field, we find 58 with detectable flare activity in at least 1 component, 33 of which are similar in mass (q > 0.8). Of these 33 equal-mass binaries, the majority display similar (±1 dex) flare luminosity between both stars, as expected for stars of equal mass and age. However, we find two equal-mass pairs where the secondary (lower mass) star is more active than its counterpart, and two equal-mass pairs where the primary star is more active. The stellar rotation periods are also anomalously fast for stars with elevated flare activity. Pairs with discrepant rotation and activity qualitatively seem to have lower mass ratios. These outliers may be due to tidal spin-up, indicating these wide binaries could be hierarchical triple systems. We additionally present high-resolution adaptive optics images for two wide binary systems to test this hypothesis. The demographics of stellar rotation and magnetic activity between stars in wide binaries may be useful indicators for discerning the formation scenarios of these systems.

  10. Robust, open-source removal of systematics in Kepler data

    OpenAIRE

    Aigrain, S.; Parviainen, H.; Roberts, S.; Reece, S.; Evans, T.

    2017-01-01

    We present ARC2 (Astrophysically Robust Correction 2), an open-source Python-based systematics-correction pipeline to correct for the Kepler prime mission long cadence light curves. The ARC2 pipeline identifies and corrects any isolated discontinuities in the light curves, then removes trends common to many light curves. These trends are modelled using the publicly available co-trending basis vectors, within an (approximate) Bayesian framework with `shrinkage' priors to minimise the risk of o...

  11. A SYSTEMATIC SEARCH FOR TROJAN PLANETS IN THE KEPLER DATA

    Energy Technology Data Exchange (ETDEWEB)

    Janson, Markus, E-mail: janson@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2013-09-10

    Trojans are circumstellar bodies that reside in characteristic 1:1 orbital resonances with planets. While all the trojans in our solar system are small ({approx}<100 km), stable planet-size trojans may exist in extrasolar planetary systems, and the Kepler telescope constitutes a formidable tool to search for them. Here we report on a systematic search for extrasolar trojan companions to 2244 known Kepler Objects of Interest (KOIs), with epicyclic orbital characteristics similar to those of the Jovian trojan families. No convincing trojan candidates are found, despite a typical sensitivity down to Earth-size objects. This fact, however, cannot be used to stringently exclude the existence of trojans in this size range, since stable trojans need not necessarily share the same orbital plane as the planet, and thus may not transit. Following this reasoning, we note that if Earth-sized trojans exist at all, they are almost certainly both present and in principle detectable in the full set of Kepler data, although a very substantial computational effort would be required to detect them. Additionally, we also note that some of the existing KOIs could in principle be trojans themselves, with a primary planet orbiting outside of the transiting plane. A few examples are given for which this is a readily testable scenario.

  12. Data Validation in the Kepler Science Operations Center Pipeline

    Science.gov (United States)

    Wu, Hayley; Twicken, Joseph D.; Tenenbaum, Peter; Clarke, Bruce D.; Li, Jie; Quintana, Elisa V.; Allen, Christopher; Chandrasekaran, Hema; Jenkins, Jon M.; Caldwell, Douglas A.; hide

    2010-01-01

    We present an overview of the Data Validation (DV) software component and its context within the Kepler Science Operations Center (SOC) pipeline and overall Kepler Science mission. The SOC pipeline performs a transiting planet search on the corrected light curves for over 150,000 targets across the focal plane array. We discuss the DV strategy for automated validation of Threshold Crossing Events (TCEs) generated in the transiting planet search. For each TCE, a transiting planet model is fitted to the target light curve. A multiple planet search is conducted by repeating the transiting planet search on the residual light curve after the model flux has been removed; if an additional detection occurs, a planet model is fitted to the new TCE. A suite of automated tests are performed after all planet candidates have been identified. We describe a centroid motion test to determine the significance of the motion of the target photocenter during transit and to estimate the coordinates of the transit source within the photometric aperture; a series of eclipsing binary discrimination tests on the parameters of the planet model fits to all transits and the sequences of odd and even transits; and a statistical bootstrap to assess the likelihood that the TCE would have been generated purely by chance given the target light curve with all transits removed. Keywords: photometry, data validation, Kepler, Earth-size planets

  13. Kepler's theory of force and his medical sources.

    Science.gov (United States)

    Regier, Jonathan

    2014-01-01

    Johannes Kepler (1571-1630) makes extensive use of souls and spiritus in his natural philosophy. Recent studies have highlighted their importance in his accounts of celestial generation and astrology. In this study, I would like to address two pressing issues. The first is Kepler's context. The biological side of his natural philosophy is not naively Aristotelian. Instead, he is up to date with contemporary discussions in medically flavored natural philosophy. I will examine his relationship to Melanchthon's anatomical-theological Liber de anima (1552) and to Jean Femel's very popular Physiologia (1567), two Galenic sources with a noticeable impact on how he understands the functions of life. The other issue that will direct my article is force at a distance. Medical ideas deeply inform Kepler's theories of light and solar force (virtus motrix). It will become clear that they are not a hindrance even to the hardcore of his celestial physics. Instead, he makes use of soul and spiritus in order to develop a fully mathematized dynamics.

  14. ROTATING STARS FROM KEPLER OBSERVED WITH GAIA DR1

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, James R. A. [Department of Physics and Astronomy, Western Washington University, 516 High Street, Bellingham, WA 98225 (United States)

    2017-01-20

    Astrometric data from the recent Gaia Data Release 1 have been matched against the sample of stars from Kepler with known rotation periods. A total of 1299 bright rotating stars were recovered from the subset of Gaia sources with good astrometric solutions, most with temperatures above 5000 K. From these sources, 894 were selected as lying near the main sequence using their absolute G -band magnitudes. These main-sequence stars show a bimodality in their rotation period distribution, centered roughly around a 600 Myr rotation isochrone. This feature matches the bimodal period distribution found in cooler stars with Kepler , but was previously undetected for solar-type stars due to sample contamination by subgiants. A tenuous connection between the rotation period and total proper motion is found, suggesting that the period bimodality is due to the age distribution of stars within ∼300 pc of the Sun, rather than a phase of rapid angular momentum loss. This work emphasizes the unique power for understanding stellar populations that is created by combining temporal monitoring from Kepler with astrometric data from Gaia .

  15. Gravitational Lensing Signatures of Long Cosmic Strings

    CERN Document Server

    De Laix, A A; Vachaspati, T; Laix, Andrew A. de; Krauss, Lawrence M.; Vachaspati, Tanmay

    1997-01-01

    The gravitational lensing by long, wiggly cosmic strings is shown to produce a large number of lensed images of a background source. In addition to pairs of images on either side of the string, a number of small images outline the string due to small-scale structure on the string. This image pattern could provide a highly distinctive signature of cosmic strings. Since the optical depth for multiple imaging of distant quasar sources by long strings may be comparable to that by galaxies, these image patterns should be clearly observable in the next generation of redshift surveys such as the Sloan Digital Sky Survey.

  16. Achromatic Cooling Channel with Li Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Balbekov, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2002-04-29

    A linear cooling channel with Li lenses, solenoids, and 201 MHz RF cavities is considered. A special lattice design is used to minimize chromatic aberrations by suppression of several betatron resonances. Transverse emittance of muon beam decreases from 2 mm to 0.5 mm at the channel of about 110 m length. Longitudinal heating is modest, therefore transmission of the channel is rather high: 96% without decay and 90% with decay. Minimal beam emittance achievable by similar channel estimated as about 0.25 mm at surface field of Li lenses 10 T.

  17. Rigid gas permeable lenses and patient management.

    Science.gov (United States)

    Terry, R; Schnider, C; Holden, B A

    1989-01-01

    The introduction of new rigid gas permeable (RGP) contact lens materials provides the practitioner with a number of alternatives for patient management. But whatever the lens materials used, problems related to the lenses, care and maintenance solutions, and patients may arise. This paper examines concerns such as parameter instability, durability of lenses, compatibility of materials and solutions, patient education and compliance, 3 and 9 o'clock staining, corneal distortion, and lid changes. Suggestions are made on ways to avoid or minimize problems related to RGP lens wear.

  18. Modern scleral contact lenses : a review

    OpenAIRE

    van der Worp, Eef; Bornman, Dina; Ferreira, Daniela Lopes; Ribeiro, Miguel Faria; Garcia-Porta, Nery; González-Méijome, José Manuel

    2014-01-01

    Scleral contact lenses (ScCL) have gained renewed interest during the last decade. Originally, they wereprimarily used for severely compromised eyes. Corneal ectasia and exposure conditions were the primaryindications. However, the indication range of ScCL in contact lens practices seems to be expanding, andit now increasingly includes less severe and even non-compromised eyes, too.All lenses that partly or entirely rest on the sclera are included under the name ScCL in this paper;although th...

  19. High-speed optical signal processing using time lenses

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Guan, Pengyu

    2015-01-01

    This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle.......This paper will discuss time lenses and their broad range of applications. A number of recent demonstrations of complex high-speed optical signal processing using time lenses will be outlined with focus on the operating principle....

  20. Atmospheric parameters of red giants in the Kepler field

    Science.gov (United States)

    Bruntt, H.; Frandsen, S.; Thygesen, A. O.

    2011-04-01

    Context. Accurate fundamental parameters of stars are mandatory for the asteroseismic investigation of the Kepler mission to succeed. Aims: We determine the atmospheric parameters for a sample of six well-studied bright K giants to confirm that our method produces reliable results. We then apply the same method to 14 K giants that are targets of the Kepler mission. Methods: We used high-resolution, high signal-to-noise ratio spectra acquired using the FIES spectrograph on the Nordic Optical Telescope. We applied the iterative spectral synthesis method VWA to derive the fundamental parameters from carefully selected high-quality iron lines and pressure-sensitive Calcium lines. Results: We find good agreement with parameters from the literature for the six bright giants. We compared the spectroscopic values with parameters based on photometric indices in the Kepler Input Catalogue (KIC). We identify serious problems with the KIC values for [Fe/H] and find a large RMS scatter of 0.5 dex. The log g values in KIC agree reasonably well with the spectroscopic values displaying a scatter of 0.25 dex after excluding two low-metallicity giants. The Teff values from VWA and KIC agree well with a scatter of about 85 K. We also find good agreement with log g and Teff derived from asteroseismic analyses for seven Kepler giant targets. Conclusions: We determine accurate fundamental parameters of 14 giants using spectroscopic data. The large discrepancies between photometric and spectroscopic values of [Fe/H] emphasize the need for further detailed spectroscopic follow-up of the Kepler targets. This will be mandatory to be able to produce reliable constraints for detailed asteroseismic analyses and interpretation of possible exo-planet candidates found around giant stars. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of

  1. Robo-AO Kepler Asteroseismic Survey. I. Adaptive Optics Imaging of 99 Asteroseismic Kepler Dwarfs and Subgiants

    International Nuclear Information System (INIS)

    Schonhut-Stasik, Jessica S.; Baranec, Christoph; Huber, Daniel; Atkinson, Dani; Hagelberg, Janis; Marel, Nienke van der; Hodapp, Klaus W.; Ziegler, Carl; Law, Nicholas M.; Gaidos, Eric; Riddle, Reed

    2017-01-01

    We used the Robo-AO laser adaptive optics (AOs) system to image 99 main sequence and subgiant stars that have Kepler -detected asteroseismic signals. Robo-AO allows us to resolve blended secondary sources at separations as close as ∼0.″15 that may contribute to the measured Kepler light curves and affect asteroseismic analysis and interpretation. We report eight new secondary sources within 4.″0 of these Kepler asteroseismic stars. We used Subaru and Keck AOs to measure differential infrared photometry for these candidate companion systems. Two of the secondary sources are likely foreground objects, while the remaining six are background sources; however, we cannot exclude the possibility that three of the objects may be physically associated. We measured a range of i ′-band amplitude dilutions for the candidate companion systems from 0.43% to 15.4%. We find that the measured amplitude dilutions are insufficient to explain the previously identified excess scatter in the relationship between asteroseismic oscillation amplitude and the frequency of maximum power.

  2. Analysis of luminosity distributions of strong lensing galaxies: subtraction of diffuse lensed signal

    Science.gov (United States)

    Biernaux, J.; Magain, P.; Hauret, C.

    2017-08-01

    Context. Strong gravitational lensing gives access to the total mass distribution of galaxies. It can unveil a great deal of information about the lenses' dark matter content when combined with the study of the lenses' light profile. However, gravitational lensing galaxies, by definition, appear surrounded by lensed signal, both point-like and diffuse, that is irrelevant to the lens flux. Therefore, the observer is most often restricted to studying the innermost portions of the galaxy, where classical fitting methods show some instabilities. Aims: We aim at subtracting that lensed signal and at characterising some lenses' light profile by computing their shape parameters (half-light radius, ellipticity, and position angle). Our objective is to evaluate the total integrated flux in an aperture the size of the Einstein ring in order to obtain a robust estimate of the quantity of ordinary (luminous) matter in each system. Methods: We are expanding the work we started in a previous paper that consisted in subtracting point-like lensed images and in independently measuring each shape parameter. We improve it by designing a subtraction of the diffuse lensed signal, based only on one simple hypothesis of symmetry. We apply it to the cases where it proves to be necessary. This extra step improves our study of the shape parameters and we refine it even more by upgrading our half-light radius measurement method. We also calculate the impact of our specific image processing on the error bars. Results: The diffuse lensed signal subtraction makes it possible to study a larger portion of relevant galactic flux, as the radius of the fitting region increases by on average 17%. We retrieve new half-light radii values that are on average 11% smaller than in our previous work, although the uncertainties overlap in most cases. This shows that not taking the diffuse lensed signal into account may lead to a significant overestimate of the half-light radius. We are also able to measure

  3. Coatings and Tints of Spectacle Lenses

    Directory of Open Access Journals (Sweden)

    H. Zeki Büyükyıldız

    2012-10-01

    Full Text Available Spectacle lenses are made of mineral or organic (plastic materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1 Anti-reflection coatings, 2 Hard coatings, 3 Clean coat, 4 Mirror coatings, 5 Color tint coating (one of coloring processes, 6 Photochromic coating (one of photochromic processes, and 7 Anti-fog coatings. Anti-reflection coatings reduce unwanted reflections from the lens surfaces and increase light transmission. Hard coatings are applied for preventing the plastic lens surface from scratches and abrasion. Hard coatings are not required for the mineral lenses due to their hardness. Clean coat makes the lens surface smooth and hydrophobic. Thus, it prevents the adherence of dust, tarnish, and dirt particles on the lens surface. Mirror coatings are applied onto the sunglasses for cosmetic purpose. Color tinted and photochromic lenses are used for sun protection and absorption of the harmful UV radiations. Anti-fog coatings make the lens surface hydrophilic and prevent the coalescence of tiny water droplets on the lens surface that reduces light transmission. (Turk J Ophthalmol 2012; 42: 359-69

  4. Optical aberrations in a gas lenses

    CSIR Research Space (South Africa)

    Mafusire, C

    2010-08-01

    Full Text Available Gas lenses work on the basis that aerodynamic media can be used to generate a graded refractive index distribution which can be used to focus a laser beam. Examples of these are the spinning pipe gas lens (SPGL) and the flame lens (FL). The SPGL...

  5. GRAVITATIONAL LENSES AND UNCONVENTIONAL GRAVITY THEORIES

    NARCIS (Netherlands)

    BEKENSTEIN, JD; SANDERS, RH

    1994-01-01

    We study gravitational lensing by clusters of galaxies in the context of the generic class of unconventional gravity theories which describe gravity in terms of a metric and one or more scalar fields (called here scalar-tensor theories). We conclude that, if the scalar fields have positive energy,

  6. Modern scleral lenses part II: patient satisfaction.

    NARCIS (Netherlands)

    Visser, E.S.; Visser, R.; Lier, H.J.J. van; Otten, H.M.

    2007-01-01

    PURPOSE: To evaluate the subjective performance of modern scleral lenses in patients of the clinics of Visser Contact Lens Practice. METHODS: In this cross-sectional survey, all the necessary data were collected at the first follow-up visit during the 5-month study period. In accordance with the

  7. Studying dark matter haloes with weak lensing

    NARCIS (Netherlands)

    Velander, Malin Barbro Margareta

    2012-01-01

    Our Universe is comprised not only of normal matter but also of unknown components: dark matter and dark energy. This Thesis recounts studies of dark matter haloes, using a technique known as weak gravitational lensing, in order to learn more about the nature of these dark components. The haloes

  8. Quantum Spin Lenses in Atomic Arrays

    Directory of Open Access Journals (Sweden)

    A. W. Glaetzle

    2017-09-01

    Full Text Available We propose and discuss quantum spin lenses, where quantum states of delocalized spin excitations in an atomic medium are focused in space in a coherent quantum process down to (essentially single atoms. These can be employed to create controlled interactions in a quantum light-matter interface, where photonic qubits stored in an atomic ensemble are mapped to a quantum register represented by single atoms. We propose Hamiltonians for quantum spin lenses as inhomogeneous spin models on lattices, which can be realized with Rydberg atoms in 1D, 2D, and 3D, and with strings of trapped ions. We discuss both linear and nonlinear quantum spin lenses: in a nonlinear lens, repulsive spin-spin interactions lead to focusing dynamics conditional to the number of spin excitations. This allows the mapping of quantum superpositions of delocalized spin excitations to superpositions of spatial spin patterns, which can be addressed by light fields and manipulated. Finally, we propose multifocal quantum spin lenses as a way to generate and distribute entanglement between distant atoms in an atomic lattice array.

  9. X-ray lenses with large aperture

    International Nuclear Information System (INIS)

    Simon, Markus

    2010-01-01

    Up to now, most X-ray imaging setups are based on absorption contrast imaging. There is a demand for focused X-rays in many X-ray analysis applications, either to increase the resolution of an imaging system, or, to reduce the time effort of an experiment through higher photon flux. For photon energies higher than 15 keV refractive X-ray optics are more efficient in comparison to non-refractive X-ray optics. The aim of this work was to develop X-ray lenses with large apertures and high transparency. By increasing the number of refracting surfaces while removing unnecessary lens material such lenses have been developed. Utilizing this approach the overall beam deflection angle is large with respect to the lens material it propagates through and so the transparency of the lens is increased. Within this work, X-ray lenses consisting of several thousands of prisms with an edge length in the range of micrometers have been developed and fabricated by deep X-ray lithography. Deep X-ray lithography enables high precision microstrucures with smooth sidewalls and large aspect ratios. The aperture of high-transparency X-ray lenses made this way is greater than 1 mm. They are suitable for photon energies in the range of 8 keV to 24 keV and offer a focal width of smaller than 10 μm at a transparency of around 40%. Furthermore, rolled X-ray lenses have been developed, that are made out of a microstructured polyimide film, which is cut according to the requirements regarding focal length and photon energy. The microstructured film is fabricated by molding, using an anisotropically etched silicon wafer as molding tool. Its mean roughness is in the range of nanometers. The film features prismatic structures, its surface topology is similar to an asparagus field. The measured diameter of the point focus was 18 μm to 31 μm, the calculated opticla efficiency was 37%. Future work will concentrate on increasing the aspect ratio of Prism Lenses and on increasing the rolling accuracy

  10. Verification of the Kepler Input Catalog from Asteroseismology of Solar-type Stars

    DEFF Research Database (Denmark)

    Verner, G.A.; Chaplin, W.J.; Basu, S.

    2011-01-01

    We calculate precise stellar radii and surface gravities from the asteroseismic analysis of over 500 solar-type pulsating stars observed by the Kepler space telescope. These physical stellar properties are compared with those given in the Kepler Input Catalog (KIC), determined from ground...

  11. An Alternative Way to Achieve Kepler's Laws of Equal Areas and Ellipses for the Earth

    Science.gov (United States)

    Hsiang, W. Y.; Chang, H. C.; Yao, H.; Chen, P. J.

    2011-01-01

    Kepler's laws of planetary motion are acknowledged as highly significant to the construction of universal gravitation. This paper demonstrates different ways to derive the law of equal areas for the Earth by general geometrical and trigonometric methods, which are much simpler than the original derivation depicted by Kepler. The established law of…

  12. The Kepler characterization of the variability among A- and F-type stars. - I: General overview

    NARCIS (Netherlands)

    Uytterhoeven, K.; Moya, A.; Grigahcène, A.; Guzik, J.A.; Gutiérrez-Soto, J.; Smalley, B.; Handler, G.; Balona, L.A.; Niemczura, E.; Fox Machado, L.; Benatti, S.; Chapellier, E.; Tkachenko, A.; Szabó, R.; Suárez, J.C.; Ripepi, V.; Pascual, J.; Mathias, P.; Martín-Ruíz, S.; Lehmann, H.; Jackiewicz, J.; Hekker, S.; Gruberbauer, M.; García, R.A.; Dumusque, X.; Díaz-Fraile, D.; Bradley, P.; Antoci, V.; Roth, M.; Leroy, B.; Murphy, S.J.; De Cat, P.; Cuypers, J.; Kjeldsen, H.; Christensen-Dalsgaard, J.; Breger, M.; Pigulski, A.; Kiss, L.L.; Still, M.; Thompson, S.E.; Van Cleve, J.

    2011-01-01

    Context. The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. Aims. We present a first general characterization of the pulsational behaviour of A-F type stars as observed in the Kepler light curves of a sample of 750

  13. VizieR Online Data Catalog: Asteroseismic analysis of 8 Kepler red giants (Arentoft+, 2017)

    Science.gov (United States)

    Arentoft, T.; Brogaard, K.; Jessen-Hansen, J.; Silva Aguirre, V.; Kjeldsen, H.; Mosumgaard, J. R.; Sandquist, E. L.

    2017-10-01

    We used Kepler long-cadence data (~30 minutes sampling) to study eight red giants in the open cluster NGC 6811. Each time series includes more than 60000 data points and spans ~1400 days (BJD 2454953-2456391, Kepler quarters Q1-Q17; 2009 May-2013 Apr) from data release 22. (3 data files).

  14. The astronomer and the witch Johannes Kepler's fight for his mother

    CERN Document Server

    Rublack, Ulinka

    2015-01-01

    The extraordinary tale of Johannes Kepler, one of the most admired astronomers of all time, and the six long years spent defending his mother from her neighbours' accusations of witchcraft. A story which takes us to the heart of Kepler's changing world.

  15. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    DEFF Research Database (Denmark)

    Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.

    2014-01-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurement...

  16. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    NARCIS (Netherlands)

    Marcy, G.W.; et al., [Unknown; Hekker, S.

    2014-01-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements,

  17. Asteroseismic diagrams from a survey of solar-like oscillations with Kepler

    NARCIS (Netherlands)

    White, T.R.; Bedding, T.R.; Stello, D.; Appourchaux, T.; Ballot, J.; Benomar, O.; Bonnano, A.; Broomhall, A.M.; Campante, T.L.; Chaplin, W.J.; Christensen-Dalsgaard, J.; Corsaro, E.; Dogan, G.; Elsworth, Y.P.; Fletcher, S.T.; Garcia, R.A.; Gaulme, P.; Handberg, R.; Hekker, S.; Huber, D.; Karoff, C.; Kjeldsen, H.; Mathur, S.; Mosser, B.; Monteiro, M.J.P.F.G.; Regulo, C.; Salabert, D.; Silva Aguirre, V.; Thompson, M.J.; Verner, G.; Morris, R.L.; Sanderfer, D.T.; Seader, S.E.

    2011-01-01

    Photometric observations made by the NASA Kepler Mission have led to a dramatic increase in the number of main-sequence and subgiant stars with detected solar-like oscillations. We present an ensemble asteroseismic analysis of 76 solar-type stars. Using frequencies determined from the Kepler

  18. Preliminary Results of Autotuning GEMM Kernels for the NVIDIA Kepler Architecture- GeForce GTX 680

    Energy Technology Data Exchange (ETDEWEB)

    Kurzak, Jakub [Univ. of Tennessee, Knoxville, TN (United States); Luszczek, Pitor [Univ. of Tennessee, Knoxville, TN (United States); Tomov, Stanimire [Univ. of Tennessee, Knoxville, TN (United States); Dongarra, Jack [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Manchester (United Kingdom)

    2012-04-01

    Kepler is the newest GPU architecture from NVIDIA, and the GTX 680 is the first commercially available graphics card based on that architecture. Matrix multiplication is a canonical computational kernel, and often the main target of initial optimization efforts for a new chip. This article presents preliminary results of automatically tuning matrix multiplication kernels for the Kepler architecture using the GTX 680 card.

  19. Ensemble asteroseismology of solar-type stars with the NASA Kepler mission

    NARCIS (Netherlands)

    Chaplin, W.J.; Kjeldsen, H.; Christensen-Dalsgaard, J.; Basu, S.; Miglio, A.; Appourchaux, T.; Bedding, T.R.; Elsworth, Y.; Garcia, R.A.; Gilliland, R.L.; Girardi, L.; Houdek, G.; Karoff, C.; Kawaler, S.D.; Metcalfe, T.S.; Molenda-Zakowicz, J.; Monteiro, M.J.P.F.G.; Thompson, M.J.; Verner, G.A.; Ballot, J.; Bonanno, A.; Brandao, I.M.; Broomhall, A.M.; Bruntt, H.; Campante, T.L.; Corsaro, E.; Creevey, O.L.; Esch, L.; Gai, N.; Gaulme, P.; Hale, S.J.; Handberg, R.; Hekker, S.; Huber, D.; Jimenez, A.; Mathur, S.; Mazumdar, A.; Mosser, B.; New, R.; Pinsonneault, M.H.; Pricopi, D.; Quirion, P.O.; Regulo, C.; Salabert, D.; Serenelli, A.M.; Silva Aguirre, V.; Sousa, S.G.; Stello, D.; Stevens, I.R.; Suran, M.D.; Uytterhoeven, K.; White, T.R.; Borucki, W.J.; Brown, T.M.; Jenkins, J.M.; Kinemuchi, K.; Van Cleve, J.; Klaus, T.C.

    2011-01-01

    In addition to its search for extrasolar planets, the NASA Kepler mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solar-type stars in the Kepler field of view, an ensemble that is large enough to allow statistical studies of intrinsic stellar

  20. Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission

    DEFF Research Database (Denmark)

    Chaplin, William J.; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen

    2011-01-01

    In addition to its search for extrasolar planets, the NASA Kepler mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solar-type stars in the Kepler field of view, an ensemble that is large enough to allow statistical studies of intrinsic stellar...

  1. Processes for manufacturing multifocal diffractive-refractive intraocular lenses

    Science.gov (United States)

    Iskakov, I. A.

    2017-09-01

    Manufacturing methods and design features of modern diffractive-refractive intraocular lenses are discussed. The implantation of multifocal intraocular lenses is the most optimal method of restoring the accommodative ability of the eye after removal of the natural lens. Diffractive-refractive intraocular lenses are the most widely used implantable multifocal lenses worldwide. Existing methods for manufacturing such lenses implement various design solutions to provide the best vision function after surgery. The wide variety of available diffractive-refractive intraocular lens designs reflects the demand for this method of vision correction in clinical practice and the importance of further applied research and development of new technologies for designing improved lens models.

  2. One of the many visiting theoreticians, R P Feynman, who gave lectures at CERN during the year

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    Visiting CERN in January was R P Feynman, who has recently been working on strong interaction theory. On 8 January, he packed the lecture theatre, as usual, when he gave a talk on inelastic hadron collisions and is here caught in a typically graphic pose.

  3. PREDICTING A THIRD PLANET IN THE KEPLER-47 CIRCUMBINARY SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Hinse, Tobias C. [Korea Astronomy and Space Science Institute (Korea, Republic of); Haghighipour, Nader [Institute for Astronomy, University of Hawaii-Manoa, Honolulu, HI (United States); Kostov, Veselin B. [Johns Hopkins University, Baltimore, MD (United States); Goździewski, Krzysztof, E-mail: tchinse@gmail.com [Toruń Centre for Astronomy of the Nicolai Copernicus University, Grudziadzka 5 (Poland)

    2015-01-20

    We have studied the possibility that a third circumbinary planet in the Kepler-47 planetary system is the source of the single unexplained transiting event reported during the discovery of these planets. We applied the MEGNO technique to identify regions in the phase space where a third planet can maintain quasi-periodic orbits, and assessed the long-term stability of the three-planet system by integrating the entire five bodies (binary + planets) for 10 Myr. We identified several stable regions between the two known planets as well as a region beyond the orbit of Kepler-47c where the orbit of the third planet could be stable. To constrain the orbit of this planet, we used the measured duration of the unexplained transit event (∼4.15 hr) and compared that with the transit duration of the third planet in an ensemble of stable orbits. To remove the degeneracy among the orbits with similar transit durations, we considered the planet to be in a circular orbit and calculated its period analytically. The latter places an upper limit of 424 days on the orbital period of the third planet. Our analysis suggests that if the unexplained transit event detected during the discovery of the Kepler-47 circumbinary system is due to a planetary object, this planet will be in a low eccentricity orbit with a semi-major axis smaller than 1.24 AU. Further constraining of the mass and orbital elements of this planet requires a re-analysis of the entire currently available data, including those obtained post-announcement of the discovery of this system. We present details of our methodology and discuss the implication of the results.

  4. Analysis Of Kepler Observations Of HAT-P-7 b

    Science.gov (United States)

    Jackson, Brian; Deming, D.

    2011-09-01

    HAT-P-7 b is among the hottest hot Jupiters ever discovered. Its orbital distance of about 4 stellar radii from an F star suggests the planet has a dayside temperature in excess of 2700 K. Moreover, HAT-P-7 b exerts tremendous tidal influence on its host star, significantly distorting the star's equilibrium shape. Prompted in part by these expectations, the Kepler mission observed the HAT-P-7 system in its short-cadence mode (i.e. 60 second integration times) from May 2009 till December 2010. Early analyses of a subset of these data have revealed the unique phenomena exhibited by this system. Borucki et al. (2009) analyzed the first ten days of observations (quarter 0) and identified atmospheric emission from the planet, suggesting a dayside temperature of 2650 K and little day-to-nightside redistribution of stellar heating. Welsh et al. (2010) followed with an analysis of 34 days of observations (quarter 1) and found an increase in flux from the system as the planet passed through quadrature. These oscillations are consistent with variations in the host star's projected surface area resulting from its tidal distortion (ellipsoidal variations). Since those analyses, another 90 days (quarter 2) of Kepler data have been made public, nearly tripling the number of planetary transits observed. This increase in the number of transits allows more complete removal of other systematic variations, facilitating a search for planetary variability. In this presentation, we will discuss our analysis of the publicly available Kepler transit data of HAT-P-7 b. We will present improved constraints on transit parameters and the ellipsoidal variations exhibited by the host star. We will also discuss our search for changes from one orbit to the next in the planet's phase curve, indicative of meteorological variability. Jackson was funded through the NASA Postdoctoral Program (NPP).

  5. PREDICTING A THIRD PLANET IN THE KEPLER-47 CIRCUMBINARY SYSTEM

    International Nuclear Information System (INIS)

    Hinse, Tobias C.; Haghighipour, Nader; Kostov, Veselin B.; Goździewski, Krzysztof

    2015-01-01

    We have studied the possibility that a third circumbinary planet in the Kepler-47 planetary system is the source of the single unexplained transiting event reported during the discovery of these planets. We applied the MEGNO technique to identify regions in the phase space where a third planet can maintain quasi-periodic orbits, and assessed the long-term stability of the three-planet system by integrating the entire five bodies (binary + planets) for 10 Myr. We identified several stable regions between the two known planets as well as a region beyond the orbit of Kepler-47c where the orbit of the third planet could be stable. To constrain the orbit of this planet, we used the measured duration of the unexplained transit event (∼4.15 hr) and compared that with the transit duration of the third planet in an ensemble of stable orbits. To remove the degeneracy among the orbits with similar transit durations, we considered the planet to be in a circular orbit and calculated its period analytically. The latter places an upper limit of 424 days on the orbital period of the third planet. Our analysis suggests that if the unexplained transit event detected during the discovery of the Kepler-47 circumbinary system is due to a planetary object, this planet will be in a low eccentricity orbit with a semi-major axis smaller than 1.24 AU. Further constraining of the mass and orbital elements of this planet requires a re-analysis of the entire currently available data, including those obtained post-announcement of the discovery of this system. We present details of our methodology and discuss the implication of the results

  6. The Resilience of Kepler Systems to Stellar Obliquity

    Science.gov (United States)

    Spalding, Christopher; Marx, Noah W.; Batygin, Konstantin

    2018-04-01

    The Kepler mission and its successor K2 have brought forth a cascade of transiting planets. Many of these planetary systems exhibit multiple members, but a large fraction possess only a single transiting example. This overabundance of singles has led to the suggestion that up to half of Kepler systems might possess significant mutual inclinations between orbits, reducing the transiting number (the so-called “Kepler Dichotomy”). In a recent paper, Spalding & Batygin demonstrated that the quadrupole moment arising from a young, oblate star is capable of misaligning the constituent orbits of a close-in planetary system enough to reduce their transit number, provided that the stellar spin axis is sufficiently misaligned with respect to the planetary orbital plane. Moreover, tightly packed planetary systems were shown to be susceptible to becoming destabilized during this process. Here, we investigate the ubiquity of the stellar obliquity-driven instability within systems with a range of multiplicities. We find that most planetary systems analyzed, including those possessing only two planets, underwent instability for stellar spin periods below ∼3 days and stellar tilts of order 30°. Moreover, we are able to place upper limits on the stellar obliquity in systems such as K2-38 (obliquity ≲20°), where other methods of measuring the spin–orbit misalignment are not currently available. Given the known parameters of T-Tauri stars, we predict that up to one-half of super-Earth-mass systems may encounter the instability, in general agreement with the fraction typically proposed to explain the observed abundance of single-transiting systems.

  7. Hot subluminous stars: Highlights from the MUCHFUSS and Kepler missions

    Directory of Open Access Journals (Sweden)

    Geier S.

    2013-03-01

    Full Text Available Research into hot subdwarf stars is progressing rapidly. We present recent important discoveries. First we review the knowledge about magnetic fields in hot subdwarfs and highlight the first detection of a highly-magnetic, helium-rich sdO star. We briefly summarize recent discoveries based on Kepler light curves and finally introduce the closest known sdB+WD binary discovered by the MUCHFUSS project and discuss its relevance as a progenitor of a double-detonation type Ia supernova.

  8. Workflows for microarray data processing in the Kepler environment

    Science.gov (United States)

    2012-01-01

    Background Microarray data analysis has been the subject of extensive and ongoing pipeline development due to its complexity, the availability of several options at each analysis step, and the development of new analysis demands, including integration with new data sources. Bioinformatics pipelines are usually custom built for different applications, making them typically difficult to modify, extend and repurpose. Scientific workflow systems are intended to address these issues by providing general-purpose frameworks in which to develop and execute such pipelines. The Kepler workflow environment is a well-established system under continual development that is employed in several areas of scientific research. Kepler provides a flexible graphical interface, featuring clear display of parameter values, for design and modification of workflows. It has capabilities for developing novel computational components in the R, Python, and Java programming languages, all of which are widely used for bioinformatics algorithm development, along with capabilities for invoking external applications and using web services. Results We developed a series of fully functional bioinformatics pipelines addressing common tasks in microarray processing in the Kepler workflow environment. These pipelines consist of a set of tools for GFF file processing of NimbleGen chromatin immunoprecipitation on microarray (ChIP-chip) datasets and more comprehensive workflows for Affymetrix gene expression microarray bioinformatics and basic primer design for PCR experiments, which are often used to validate microarray results. Although functional in themselves, these workflows can be easily customized, extended, or repurposed to match the needs of specific projects and are designed to be a toolkit and starting point for specific applications. These workflows illustrate a workflow programming paradigm focusing on local resources (programs and data) and therefore are close to traditional shell scripting or

  9. KIC2569073, A second Cepheid in the Kepler FOV

    Directory of Open Access Journals (Sweden)

    Drury Jason A.

    2015-01-01

    Full Text Available One particularly interesting new variable discovered via Kepler’s 200x200 pixel superstamp images is KIC2569073. With a period of 14.66 days and 0.04mag variability it is only the second Cepheid in the Kepler field, or a rotationally modulated variable. We discuss its classification as a Type II W Virginis Class Cepheid, and present the cycle-to-cycle period variations of this star, as well as the first direct observations of granulation noise within a Cepheid.

  10. Kepler Mission Design, Realized Photometric Performance, and Early Science

    DEFF Research Database (Denmark)

    Koch, David G.; Borucki, William J.; Basri, Gibor

    2010-01-01

    The Kepler Mission, launched on 2009 March 6, was designed with the explicit capability to detect Earth-size planets in the habitable zone of solar-like stars using the transit photometry method. Results from just 43 days of data along with ground-based follow-up observations have identified five...... new transiting planets with measurements of their masses, radii, and orbital periods. Many aspects of stellar astrophysics also benefit from the unique, precise, extended, and nearly continuous data set for a large number and variety of stars. Early results for classical variables and eclipsing stars...

  11. The Albedos of Kepler's Close-in super-Earths

    OpenAIRE

    Demory, Brice-Olivier

    2014-01-01

    Exoplanet research focusing on the characterization of super-Earths is currently limited to those handful targets orbiting bright stars that are amenable to detailed study. This Letter proposes to look at alternative avenues to probe the surface and atmospheric properties of this category of planets, known to be ubiquitous in our galaxy. I conduct Markov Chain Monte Carlo lightcurve analyses for 97 Kepler close-in $R_P \\lesssim 2.0 R_{\\oplus}$ super-Earth candidates with the aim to detect the...

  12. Workflows for microarray data processing in the Kepler environment

    Directory of Open Access Journals (Sweden)

    Stropp Thomas

    2012-05-01

    Full Text Available Abstract Background Microarray data analysis has been the subject of extensive and ongoing pipeline development due to its complexity, the availability of several options at each analysis step, and the development of new analysis demands, including integration with new data sources. Bioinformatics pipelines are usually custom built for different applications, making them typically difficult to modify, extend and repurpose. Scientific workflow systems are intended to address these issues by providing general-purpose frameworks in which to develop and execute such pipelines. The Kepler workflow environment is a well-established system under continual development that is employed in several areas of scientific research. Kepler provides a flexible graphical interface, featuring clear display of parameter values, for design and modification of workflows. It has capabilities for developing novel computational components in the R, Python, and Java programming languages, all of which are widely used for bioinformatics algorithm development, along with capabilities for invoking external applications and using web services. Results We developed a series of fully functional bioinformatics pipelines addressing common tasks in microarray processing in the Kepler workflow environment. These pipelines consist of a set of tools for GFF file processing of NimbleGen chromatin immunoprecipitation on microarray (ChIP-chip datasets and more comprehensive workflows for Affymetrix gene expression microarray bioinformatics and basic primer design for PCR experiments, which are often used to validate microarray results. Although functional in themselves, these workflows can be easily customized, extended, or repurposed to match the needs of specific projects and are designed to be a toolkit and starting point for specific applications. These workflows illustrate a workflow programming paradigm focusing on local resources (programs and data and therefore are close to

  13. Extension of Gauss' method for the solution of Kepler's equation

    Science.gov (United States)

    Battin, R. H.; Fill, T. J.

    1978-01-01

    Gauss' method for solving Kepler's equation is extended to arbitrary epochs and orbital eccentricities. Although originally developed for near parabolic orbits in the vicinity of pericenter, a generalization of the method leads to a highly efficient algorithm which compares favorably to other methods in current use. A key virtue of the technique is that convergence is obtained by a method of successive substitutions with an initial approximation that is independent of the orbital parameters. The equations of the algorithm are universal, i.e., independent of the nature of the orbit whether elliptic, hyperbolic, parabolic or rectilinear.

  14. Calibration of fisheye lenses for hemispherical photography

    International Nuclear Information System (INIS)

    Diaci, J.; Kolar, U.

    2000-01-01

    Hemispherical photography represents one of the most appropriate methods of estimating averages of solar radiation over extended periods of time. This method is based upon the use of extremely wide-angle fisheye lenses, which produce large projection distortion. To correctly interpret hemispherical photography we have to know the projection characteristics of the fisheye lens in combination with a camera body. This can be achieved through lens calibration. The first part of the article explains in detail the calibration method for fisheye lenses which are used to assess the solar radiation in forest ecology research. In the second part the results of calibration for fisheye lens Sigma 8 mm, f/4 (MF, N) are presented. The lens was used on a Nikon F50 camera body

  15. Astrophysical observations: lensing and eclipsing Einstein's theories.

    Science.gov (United States)

    Bennett, Charles L

    2005-02-11

    Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics.

  16. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    This thesis deals with the development of silicon compound refractive lenses (Si-CRLs) for shaping hard x-ray beams. The CRLs are to be fabricated using state of the art microfabrication techniques. The primary goal of the thesis work is to produce Si-CRLs with considerably increased structure...... intense and wider line beams with narrower waists. The thesis starts with a review of alternative x-ray lenses. Si-CRLs are identified as valuable optical components that allow shaping hard x-rays efficiently and creating beam waists that are clearly in the nanometer range. They stand out...... and characterized with respect to their shape. Their optical performances were tested at the European Synchrotron Radiation Facility (ESRF). Two 1D-focusing Si-CRLs suitable as condensers in hard-XRM were developed utilizing the aforementioned two different strategies. The first Si-condenser showed focusing of a 56...

  17. Contact lenses for ophthalmic drug delivery.

    Science.gov (United States)

    Hui, Alex

    2017-09-01

    Contact lenses as a means to deliver pharmaceuticals to the eye have seen a significant increase in research interest in the past few years. This review will detail the in vitro experiments which have investigated use of these contact lenses in the context of the desired pharmacological treatment goals in the management of infectious, inflammatory, allergic and glaucomatous diseases of the eye. The techniques researchers have employed to modify and tailor drug release rates from these materials, including the use of vitamin E diffusion barriers, modified ionicity, molecular imprinting and incorporation of drug reservoirs, will be discussed, as well as their impact on drug release kinetics. Finally, the demonstration of the feasibility of these materials when applied in vivo in animal models as well as in humans with and without disease will be presented and their results discussed relating to their implications for the future of the field. © 2017 Optometry Australia.

  18. Design considerations for liquid crystal contact lenses

    Science.gov (United States)

    Bailey, J.; Kaur, S.; Morgan, P. B.; Gleeson, H. F.; Clamp, J. H.; Jones, J. C.

    2017-12-01

    Switchable liquid crystal contact lenses with electrically controllable focal powers have previously been investigated as an alternative to bifocal contact lenses and spectacles for the correction of presbyopia. The simplest lens design uses a meniscus shaped cavity within the lens to contain the liquid crystal. The design of such a lens is considered in detail, including the nematic alignment and electrodes materials. The organic transparent conductor PEDOT:PSS was used as both electrode and planar alignment. Four different configurations are considered, using both planar and homeotropic orientations with either homogenous or axial alignment. Controllable switching of the focal power was demonstrated for each mode and focal power changes of up to ΔP  =  3.3  ±  0.2 D achieved. Such lens designs offer significant potential for a novel form of correction for this common visual problem.

  19. Irregular Corneas: Improve Visual Function With Scleral Contact Lenses.

    Science.gov (United States)

    de Luis Eguileor, Beatriz; Etxebarria Ecenarro, Jaime; Santamaria Carro, Alaitz; Feijoo Lera, Raquel

    2016-10-20

    To assess visual function in patients with irregular cornea who do not tolerate gas permeable (GP) corneal contact lenses and are fitted with GP scleral contact lenses (Rose K2 XL). In this prospective study, we analyzed 15 eyes of 15 patients who did not tolerate GP corneal contact lenses and were fitted with scleral contact lenses (Rose K2 XL). We assessed visual function using visual acuity and the visual function index (VF-14); we used the VF-14 as an indicator of patient satisfaction. The measurements were taken with the optical correction used before and 1 month after the fitting of the Rose K2 XL contact lenses. We also recorded the number of hours lenses had been worn over the first month. Using Rose K2 XL contact lenses, visual acuity was 0.06±0.07 logMAR. In all cases, visual acuity had improved compared with the measurement before fitting the lenses (0.31±0.18 logMAR; P=0.001). VF-14 scores were 72.74±12.38 before fitting of the scleral lenses, and 89.31±10.87 after 1 month of lens use (P=0.003). Patients used these scleral lenses for 9.33±2.99 comfortable hours of wear. Both visual acuity and VF-14 may improve after fitting Rose K2 XL contact lenses in patients with irregular corneas. In addition, in our patients, these lenses can be worn for a longer period than GP corneal contact lenses.

  20. Fitting gravitational lenses: truth or delusion

    Science.gov (United States)

    Evans, N. Wyn; Witt, Hans J.

    2003-11-01

    The observables in a strong gravitational lens are usually just the image positions and sometimes the flux ratios. We develop a new and simple algorithm which allows a set of models to be fitted exactly to the observations. Taking our cue from the strong body of evidence that early-type galaxies are close to isothermal, we assume that the lens is scale-free with a flat rotation curve. External shear can be easily included. Our algorithm allows full flexibility regarding the angular structure of the lensing potential. Importantly, all the free parameters enter linearly into the model and so the lens and flux ratio equations can always be solved by straightforward matrix inversion. The models are only restricted by the fact that the surface mass density must be positive. We use this new algorithm to examine some of the claims made for anomalous flux ratios. It has been argued that such anomalies betray the presence of substantial amounts of substructure in the lensing galaxy. We demonstrate by explicit construction that some of the lens systems for which substructure has been claimed can be well fitted by smooth lens models. This is especially the case when the systematic errors in the flux ratios (caused by microlensing or differential extinction) are taken into account. However, there is certainly one system (B1422+231) for which the existing smooth models are definitely inadequate and for which substructure may be implicated. Within a few tens of kpc of the lensing galaxy centre, dynamical friction and tidal disruption are known to be very efficient at dissolving any substructure. Very little substructure is projected within the Einstein radius. The numbers of strong lenses for which substructure is currently being claimed may be so large that this contradicts rather than supports cold dark matter theories.

  1. Gravitational lensing by a Horndeski black hole

    Energy Technology Data Exchange (ETDEWEB)

    Badia, Javier [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Eiroa, Ernesto F. [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Universidad de Buenos Aires, Ciudad Universitaria Pabellon I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2017-11-15

    In this article we study gravitational lensing by non-rotating and asymptotically flat black holes in Horndeski theory. By adopting the strong deflection limit, we calculate the deflection angle, from which we obtain the positions and the magnifications of the relativistic images. We compare our results with those corresponding to black holes in General Relativity. We analyze the astrophysical consequences in the case of the nearest supermassive black holes. (orig.)

  2. Gravitational lensing of the SNLS supernovae

    International Nuclear Information System (INIS)

    Kronborg, T.

    2011-01-01

    Type Ia supernovae have become an essential tool of modern observational cosmology. By studying the distance-redshift relation of a large number of supernovae, the nature of dark energy can be unveiled. Distances to Type Ia SNe are however affected by gravitational lensing which can induce systematic effects in the measurement of cosmology. The majority of the supernovae is slightly de-magnified whereas a small fraction is significantly magnified due to the mass distribution along the line of sight. This causes naturally an additional dispersion in the observed magnitudes. There are two different ways to estimate the magnification of a supernova. A first method consists in comparing the supernova luminosity, which is measured to about 15% precision, to the mean SN luminosity at the same redshift. Another estimate can be obtained from predicting the magnification induced by the foreground matter density modeled from the measurements of the luminosity of the galaxies with an initial prior on the mass-luminosity relation of the galaxies. A correlation between these 2 estimates will make it possible to tune the initially used mass-luminosity relation resulting in an independent measurement of the dark matter clustering based on the luminosity of SNe Ia. Evidently, this measurement depends crucially on the detection of this correlation also referred to as the lensing signal. This thesis is dedicated to the measurement of the lensing signal in the SNLS 3-year sample. (author)

  3. Personal radon dosimetry from eyeglass lenses

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, R.L.; Meyer, N.R.; Hadley, S.A.; MacDonald, J.; Cavallo, A

    2001-07-01

    Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosemeters. Samples of such lenses have been obtained, etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration, and with a uranium-based source of alpha particles as a convenient secondary standard. With one exception natural, environmental (fossil) track densities ranged from less than 3,000 to nearly 70,000 per cm{sup 2} for eyeglasses that had been worn for various times from one to nearly five years. Average radon concentrations to which those wearers were exposed are inferred to be in the range 14 to 130 Bq.m{sup -3} (0.4 to 3.5 pCi.l{sup -1}). A protocol for consistent, meaningful readout is derived and used. In the exceptional case the fossil track density was 1,780,000 cm{sup -2}, and the inferred (24 h) average radon concentration was 6500 Bq.m{sup -3} (175 pCi.l{sup -1}) for a worker at an inactive uranium mine that is used for therapy. (author)

  4. Electron lenses for the large hadron collider

    CERN Document Server

    Stancari†, G; Bruce, R; Redaelli, S; Rossi, A; Salvachua Ferrando, B

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beamswhose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-bybunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beamcompensation, and for the demonstration of halo scrapingwith hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. A conceptual design was recently completed, and the project is moving towards a technical design in 2014–2015 for construction in 2015–2017, if needed, after resuming LHC operations and re-assessing collimation needs and requirements at 6.5 TeV. Because of the...

  5. Automation Enhancement of Multilayer Laue Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Lauer K. R.; Conley R.

    2010-12-01

    X-ray optics fabrication at Brookhaven National Laboratory has been facilitated by a new, state of the art magnetron sputtering physical deposition system. With its nine magnetron sputtering cathodes and substrate carrier that moves on a linear rail via a UHV brushless linear servo motor, the system is capable of accurately depositing the many thousands of layers necessary for multilayer Laue lenses. I have engineered a versatile and automated control program from scratch for the base system and many subsystems. Its main features include a custom scripting language, a fully customizable graphical user interface, wireless and remote control, and a terminal-based interface. This control system has already been successfully used in the creation of many types of x-ray optics, including several thousand layer multilayer Laue lenses.Before reaching the point at which a deposition can be run, stencil-like masks for the sputtering cathodes must be created to ensure the proper distribution of sputtered atoms. Quality of multilayer Laue lenses can also be difficult to measure, given the size of the thin film layers. I employ my knowledge of software and algorithms to further ease these previously painstaking processes with custom programs. Additionally, I will give an overview of an x-ray optic simulator package I helped develop during the summer of 2010. In the interest of keeping my software free and open, I have worked mostly with the multiplatform Python and the PyQt application framework, utilizing C and C++ where necessary.

  6. DEEP GALEX UV SURVEY OF THE KEPLER FIELD. I. POINT SOURCE CATALOG

    International Nuclear Information System (INIS)

    Olmedo, Manuel; Chávez, Miguel; Bertone, Emanuele; Lloyd, James; Mamajek, Eric E.; Martin, D. Christopher; Neill, James D.

    2015-01-01

    We report observations of a deep near-ultraviolet (NUV) survey of the Kepler field made in 2012 with the Galaxy Evolution Explorer (GALEX) Complete All-Sky UV Survey Extension (CAUSE). The GALEX-CAUSE Kepler survey (GCK) covers 104 square degrees of the Kepler field and reaches a limiting magnitude of NUV ≃ 22.6 at 3σ. Analysis of the GCK survey has yielded a catalog of 669,928 NUV sources, of which 475,164 are cross-matched with stars in the Kepler Input Catalog. Approximately 327 of 451 confirmed exoplanet host stars and 2614 of 4696 candidate exoplanet host stars identified by Kepler have NUV photometry in the GCK survey. The GCK catalog should enable the identification and characterization of UV-excess stars in the Kepler field (young solar-type and low-mass stars, chromospherically active binaries, white dwarfs, horizontal branch stars, etc.), and elucidation of various astrophysics problems related to the stars and planetary systems in the Kepler field

  7. PLANETARY CANDIDATES OBSERVED BY KEPLER IV: PLANET SAMPLE FROM Q1-Q8 (22 MONTHS)

    International Nuclear Information System (INIS)

    Burke, Christopher J.; Mullally, F.; Rowe, Jason F.; Thompson, Susan E.; Coughlin, Jeffrey L.; Caldwell, Douglas A.; Jenkins, Jon M.; Bryson, Stephen T.; Haas, Michael R.; Batalha, Natalie M.; Borucki, William J.; Christiansen, Jessie L.; Ciardi, David R.; Still, Martin; Barclay, Thomas; Chaplin, William J.; Clarke, Bruce D.; Cochran, William D.; Demory, Brice-Olivier; Esquerdo, Gilbert A.

    2014-01-01

    We provide updates to the Kepler planet candidate sample based upon nearly two years of high-precision photometry (i.e., Q1-Q8). From an initial list of nearly 13,400 threshold crossing events, 480 new host stars are identified from their flux time series as consistent with hosting transiting planets. Potential transit signals are subjected to further analysis using the pixel-level data, which allows background eclipsing binaries to be identified through small image position shifts during transit. We also re-evaluate Kepler Objects of Interest (KOIs) 1-1609, which were identified early in the mission, using substantially more data to test for background false positives and to find additional multiple systems. Combining the new and previous KOI samples, we provide updated parameters for 2738 Kepler planet candidates distributed across 2017 host stars. From the combined Kepler planet candidates, 472 are new from the Q1-Q8 data examined in this study. The new Kepler planet candidates represent ∼40% of the sample with R P ∼ 1 R ⊕ and represent ∼40% of the low equilibrium temperature (T eq < 300 K) sample. We review the known biases in the current sample of Kepler planet candidates relevant to evaluating planet population statistics with the current Kepler planet candidate sample

  8. NO TIMING VARIATIONS OBSERVED IN THIRD TRANSIT OF SNOW-LINE EXOPLANET KEPLER-421b

    International Nuclear Information System (INIS)

    Dalba, Paul A.; Muirhead, Philip S.

    2016-01-01

    We observed Kepler-421 during the anticipated third transit of the snow-line exoplanet Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Previously, the Kepler spacecraft only observed two transits of Kepler-421b, leaving the planet’s transit ephemeris unconstrained. Our visible light, time-series observations from the 4.3 m Discovery Channel Telescope were designed to capture pre-transit baseline and the partial transit of Kepler-421b, barring significant TTVs. We use the light curves to assess the probabilities of various transit models using both the posterior odds ratio and the Bayesian Information Criterion, and find that a transit model with no TTVs is favored to 3.6 σ confidence. These observations suggest that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the Kepler-421b ephemeris constrained, we calculate future transit times and discuss the opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy. Our investigation emphasizes the difficulties associated with observing long-period exoplanet transits and the consequences that arise from failing to refine transit ephemerides.

  9. The Kepler Eclipsing Binary V2281 Cygni with Twin Stars

    Science.gov (United States)

    Koo, Jae-Rim; Lee, Jae Woo; Hong, Kyeongsoo

    2017-12-01

    We present the physical properties of the eclipsing binary V2281 Cyg, which shows a light-time effect due to a supposed tertiary component from its eclipse timing variation according to the Kepler observations. The high-resolution spectra and BVR photometric data of the system were obtained at Bohyunsan Optical Astronomy Observatory and Mount Lemmon Optical Astronomy Observatory, respectively. To determine the fundamental parameters of the eclipsing pair and its circumbinary object, we simultaneously analyzed the radial velocities, light curves, and eclipse times including the Kepler data. The masses and radii for the primary and secondary stars were determined with accuracy levels of approximately 2% and 1%, respectively, as follows: {M}1=1.61+/- 0.04 {M}⊙ and {M}2=1.60+/- 0.04 {M}⊙ , {R}1=1.94+/- 0.02 {R}⊙ and {R}2=1.93+/- 0.02 {R}⊙ . If its orbit is coplanar with the eclipsing binary, the period and semimajor axis of the third body were calculated to be {P}3b=4.1 years and {a}3b=4.06 {au}, respectively, and its mass is {M}3b=0.75 {M}⊙ . The evolutionary state of the system was investigated by comparing the masses and radii with theoretical models. The results demonstrate that V2281 Cyg is a detached eclipsing binary, which consists of twin main-sequence stars with an age of 1.5 Gyr.

  10. ROTATION PERIODS OF WIDE BINARIES IN THE KEPLER FIELD

    International Nuclear Information System (INIS)

    Janes, K. A.

    2017-01-01

    In a search of proper motion catalogs for common proper motion stars in the field of the Kepler spacecraft I identified 93 likely binary systems. A comparison of their rotation periods is a test of the gyrochronology concept. To find their periods I calculated the autocorrelation function (ACF) of the Kepler mission photometry for each star. In most systems for which good periods can be found, the cooler star has a longer period than the hotter component, in general agreement with models. However, there is a wide range in the gradients of lines connecting binary pairs in a period–color diagram. Furthermore, near the solar color, only a few stars have longer periods than the Sun, suggesting that they, and their cooler companions, are not much older than the Sun. In addition, there is an apparent gap at intermediate periods in the period distribution of the late K and early M stars. Either star formation in this direction has been variable, or stars evolve in period at a non-uniform rate, or some stars evolve more rapidly than others at the same mass. Finally, using the ACF as a measure of the activity level, I found that while the F, G, and early K stars become less active as their periods increase, there is no correlation between period and activity for the mid K to early M stars.

  11. Prevalence and Properties of Planets from Kepler and K2

    Science.gov (United States)

    Petigura, Erik; Marcy, Geoffrey W.; Howard, Andrew; Crossfield, Ian; Beichman, Charles; Sinukoff, Evan

    2015-12-01

    Discoveries from the prime Kepler mission demonstrated that small planets (formation around G, K, and M stars. While Kepler detected many such planets, all but a handful orbit faint, distant stars, which are not amenable to precise follow up measurements. NASA's K2 mission has the potential to increase the number of known small, transiting planets around bright stars by an order of magnitude. I will present the latest results from my team's efforts to detect, confirm, and characterize planets using the K2 mission. I will highlight some of the progress and remaining challenges involved with generating denoised K2 photometry and with detecting planets in the presence of severe instrument systematics. Among our recent discoveries are the K2-3 and K2-21 planetary systems: M dwarfs hosting multiple transiting Earth-size planets with low equilibrium temperatures. These systems offer a convenient laboratory for studying the bulk composition and atmospheric properties of small planets receiving low levels of stellar irradiation, where processes such as mass loss by photo-evaporation could play a weaker role.

  12. KEPLER MISSION STELLAR AND INSTRUMENT NOISE PROPERTIES REVISITED

    Energy Technology Data Exchange (ETDEWEB)

    Gilliland, Ronald L.; Ramsey, Lawrence W. [Department of Astronomy and Astrophysics, and Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Chaplin, William J. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Jenkins, Jon M.; Smith, Jeffrey C., E-mail: gillil@stsci.edu [NASA Ames Research Center, Moffett Field, CA 95035 (United States)

    2015-10-15

    An earlier study of the Kepler Mission noise properties on timescales of primary relevance to detection of exoplanet transits found that higher than expected noise followed, to a large extent, from the stars rather than instrument or data analysis performance. The earlier study over the first six quarters of Kepler data is extended to the full four years ultimately comprising the mission. Efforts to improve the pipeline data analysis have been successful in reducing noise levels modestly as evidenced by smaller values derived from the current data products. The new analyses of noise properties on transit timescales show significant changes in the component attributed to instrument and data analysis, with essentially no change in the inferred stellar noise. We also extend the analyses to timescales of several days, instead of several hours to better sample stellar noise that follows from magnetic activity. On the longer timescale there is a shift in stellar noise for solar-type stars to smaller values in comparison to solar values.

  13. THE CLASSIFICATION OF KEPLER B-STAR VARIABLES

    International Nuclear Information System (INIS)

    McNamara, Bernard J.; Jackiewicz, Jason; McKeever, Jean

    2012-01-01

    The light curves of 252 B-star candidates in the Kepler database are analyzed in a similar fashion to that done by Balona et al. to further characterize B-star variability, increase the sample of variable B stars for future study, and to identify stars whose power spectra include particularly interesting features such as frequency groupings. Stars are classified as either constant light emitters, β Cep stars, slowly pulsating B stars (SPBs), hybrid pulsators, binaries or stars whose light curves are dominated by rotation (Bin/Rot), hot subdwarfs, or white dwarfs. One-hundred stars in our sample were found to be either light constants or to be variable at a level of less than 0.02 mmag. We increase the number of candidate B-star variables found in the Kepler database by Balona et al. in the following fashion: β Cep stars from 0 to 10, SPBs from eight to 54, hybrid pulsators from seven to 21, and Bin/Rot stars from 23 to 82. For comparison purposes, approximately 51 SPBs and six hybrids had been known prior to 2007. The number of β Cep stars known prior to 2004 was 93. A secondary result of this study is the identification of an additional 11 pulsating white dwarf candidates, four of which possess frequency groupings.

  14. The Resilience of Kepler Multi-systems to Stellar Obliquity

    Science.gov (United States)

    Spalding, Christopher; Marx, Noah W.; Batygin, Konstantin

    2018-04-01

    The Kepler mission and its successor K2 have brought forth a cascade of transiting planets. Many of these planetary systems exhibit multiple transiting members. However, a large fraction possesses only a single transiting planet. This high abundance of singles, dubbed the "Kepler Dichotomy," has been hypothesized to arise from significant mutual inclinations between orbits in multi-planet systems. Alternatively, the single-transiting population truly possesses no other planets in the system, but the true origin of the overabundance of single systems remains unresolved. In this work, we propose that planetary systems typically form with a coplanar, multiple-planetary architecture, but that quadrupolar gravitational perturbations from their rapidly-rotating host star subsequently disrupt this primordial coplanarity. We demonstrate that, given sufficient stellar obliquity, even systems beginning with 2 planetary constituents are susceptible to dynamical instability soon after planet formation, as a result of the stellar quadrupole moment. This mechanism stands as a widespread, yet poorly explored pathway toward planetary system instability. Moreover, by requiring that observed multi-systems remain coplanar on Gyr timescales, we are able to place upper limits on the stellar obliquity in systems such as K2-38 (obliquity < 20 degrees), where other methods of measuring spin-orbit misalignment are not currently available.

  15. Effect of Kepler calibration on global seismic and background parameters

    Directory of Open Access Journals (Sweden)

    Salabert David

    2017-01-01

    Full Text Available Calibration issues associated to scrambled collateral smear affecting the Kepler short-cadence data were discovered in the Data Release 24 and were found to be present in all the previous data releases since launch. In consequence, a new Data Release 25 was reprocessed to correct for these problems. We perform here a preliminary study to evaluate the impact on the extracted global seismic and background parameters between data releases. We analyze the sample of seismic solar analogs observed by Kepler in short cadence between Q5 and Q17. We start with this set of stars as it constitutes the best sample to put the Sun into context along its evolution, and any significant differences on the seismic and background parameters need to be investigated before any further studies of this sample can take place. We use the A2Z pipeline to derive both global seismic parameters and background parameters from the Data Release 25 and previous data releases and report on the measured differences.

  16. ROTATION PERIODS OF WIDE BINARIES IN THE KEPLER FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Janes, K. A. [Astronomy Department, Boston University, Boston, MA 02215 (United States)

    2017-01-20

    In a search of proper motion catalogs for common proper motion stars in the field of the Kepler spacecraft I identified 93 likely binary systems. A comparison of their rotation periods is a test of the gyrochronology concept. To find their periods I calculated the autocorrelation function (ACF) of the Kepler mission photometry for each star. In most systems for which good periods can be found, the cooler star has a longer period than the hotter component, in general agreement with models. However, there is a wide range in the gradients of lines connecting binary pairs in a period–color diagram. Furthermore, near the solar color, only a few stars have longer periods than the Sun, suggesting that they, and their cooler companions, are not much older than the Sun. In addition, there is an apparent gap at intermediate periods in the period distribution of the late K and early M stars. Either star formation in this direction has been variable, or stars evolve in period at a non-uniform rate, or some stars evolve more rapidly than others at the same mass. Finally, using the ACF as a measure of the activity level, I found that while the F, G, and early K stars become less active as their periods increase, there is no correlation between period and activity for the mid K to early M stars.

  17. Five Kepler target stars that show multiple transiting exoplanet candidates

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Buchhave, Lars A.; /Harvard-Smithsonian Ctr. Astrophys. /Bohr Inst.; Caldwell, Douglas A.; /NASA, Ames /SETI Inst., Mtn. View; Cochran, William D.; /Texas U.; Endl, Michael; /Texas U.; Fabrycky, Daniel C.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Fortney, Jonathan J.; /UC, Santa Cruz, Phys. Dept. /NASA, Ames

    2010-06-01

    We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets and provide new insights into the formation and dynamical evolution of planetary systems. We discuss the methods used to identify multiple transiting objects from the Kepler photometry as well as the false-positive rejection methods that have been applied to these data. One system shows transits from three distinct objects while the remaining four systems show transits from two objects. Three systems have planet candidates that are near mean motion commensurabilities - two near 2:1 and one just outside 5:2. We discuss the implications that multitransiting systems have on the distribution of orbital inclinations in planetary systems, and hence their dynamical histories; as well as their likely masses and chemical compositions. A Monte Carlo study indicates that, with additional data, most of these systems should exhibit detectable transit timing variations (TTV) due to gravitational interactions - though none are apparent in these data. We also discuss new challenges that arise in TTV analyses due to the presence of more than two planets in a system.

  18. Characterizing the Habitable Zone Planets of Kepler Stars

    Science.gov (United States)

    Fischer, Debra

    Planet Hunters (PH) is a well-established and successful web interface that allows citizen scientists to search for transiting planets in the NASA Kepler public archive data. Over the past 3 years, our users have made more than 20 million light curve classifications. We now have more than 300,000 users around the world. However, more than half of the Kepler data has not yet been displayed to our volunteers. In June 2014 we are launching Planet Hunters v2.0. The backend of the site has been completely redesigned. The new website is more intuitive and faster; we have improved the real-time weighting algorithm that assigns transit scores for faster and more accurate extraction of the transit events from the database. With Planet Hunters v2.0, we expect that assessments will be ten times faster, so that we have the opportunity to complete the classifications for the backlog of Kepler light curve in the next three years. There are three goals for this project. First, we will data-mine the PH classifications to search for long period planets with fewer than 5 transit events. We have demonstrated that our volunteers are efficient at detecting planets with long periods and radii greater than a few REARTH. This region of parameter space is optimal for characterizing larger planets orbiting close to the habitable zone. To build upon the citizen science efforts, we will model the light curves, search for evidence of false positives, and contribute observations of stellar spectra to refine both the stellar and orbital parameters. Second, we will carry out a careful analysis of the fraction of transits that are missed (a function of planet radius and orbital period) to derive observational incompleteness factors. The incompleteness factors will be combined with geometrical detection factors to assess the planet occurrence rate for wide separations. This is a unique scientific contribution current studies of planet occurrence rate are either restricted to orbital periods shorter

  19. Discovery of a New AM CVn System with the Kepler Satellite

    DEFF Research Database (Denmark)

    Fontaine, G.; Brassard, P.; Green, Elizabeth M.

    2011-01-01

    We report the discovery of a new AM CVn system on the basis of broadband photometry obtained with the Kepler satellite supplemented by ground-based optical spectroscopy. Initially retained on Kepler target lists as a potential compact pulsator, the blue object SDSS J190817.07+394036.4 (KIC......, we infer preliminary estimates of the rate of mass transfer, the inclination angle of the disk, and the distance to the system. The AM CVn nature of the system is also evident in the Kepler light curve, from which we extracted 11 secure periodicities. The luminosity variations are dominated...

  20. Galaxy–Galaxy Weak-lensing Measurements from SDSS. I. Image Processing and Lensing Signals

    International Nuclear Information System (INIS)

    Luo, Wentao; Yang, Xiaohu; Zhang, Jun; Tweed, Dylan; Fu, Liping; Shu, Chenggang; Mo, H. J.; Bosch, Frank C. van den; Li, Ran; Li, Nan; Liu, Xiangkun; Pan, Chuzhong; Wang, Yiran; Radovich, Mario

    2017-01-01

    We present our image processing pipeline that corrects the systematics introduced by the point-spread function (PSF). Using this pipeline, we processed Sloan Digital Sky Survey (SDSS) DR7 imaging data in r band and generated a galaxy catalog containing the shape information. Based on our shape measurements of the galaxy images from SDSS DR7, we extract the galaxy–galaxy (GG) lensing signals around foreground spectroscopic galaxies binned in different luminosities and stellar masses. We estimated the systematics, e.g., selection bias, PSF reconstruction bias, PSF dilution bias, shear responsivity bias, and noise rectification bias, which in total is between −9.1% and 20.8% at 2 σ levels. The overall GG lensing signals we measured are in good agreement with Mandelbaum et al. The reduced χ 2 between the two measurements in different luminosity bins are from 0.43 to 0.83. Larger reduced χ 2 from 0.60 to 1.87 are seen for different stellar mass bins, which is mainly caused by the different stellar mass estimator. The results in this paper with higher signal-to-noise ratio are due to the larger survey area than SDSS DR4, confirming that more luminous/massive galaxies bear stronger GG lensing signals. We divide the foreground galaxies into red/blue and star-forming/quenched subsamples and measure their GG lensing signals. We find that, at a specific stellar mass/luminosity, the red/quenched galaxies have stronger GG lensing signals than their counterparts, especially at large radii. These GG lensing signals can be used to probe the galaxy–halo mass relations and their environmental dependences in the halo occupation or conditional luminosity function framework.

  1. Galaxy–Galaxy Weak-lensing Measurements from SDSS. I. Image Processing and Lensing Signals

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wentao [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China); Yang, Xiaohu; Zhang, Jun; Tweed, Dylan [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Fu, Liping; Shu, Chenggang [Shanghai Key Lab for Astrophysics, Shanghai Normal University, 100 Guilin Road, 200234, Shanghai (China); Mo, H. J. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Bosch, Frank C. van den [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Li, Ran [Key Laboratory for Computational Astrophysics, Partner Group of the Max Planck Institute for Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Li, Nan [Department of Astronomy and Astrophysics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Liu, Xiangkun; Pan, Chuzhong [Department of Astronomy, Peking University, Beijing 100871 (China); Wang, Yiran [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States); Radovich, Mario, E-mail: walt@shao.ac.cn, E-mail: xyang@sjtu.edu.cn [INAF-Osservatorio Astronomico di Napoli, via Moiariello 16, I-80131 Napoli (Italy)

    2017-02-10

    We present our image processing pipeline that corrects the systematics introduced by the point-spread function (PSF). Using this pipeline, we processed Sloan Digital Sky Survey (SDSS) DR7 imaging data in r band and generated a galaxy catalog containing the shape information. Based on our shape measurements of the galaxy images from SDSS DR7, we extract the galaxy–galaxy (GG) lensing signals around foreground spectroscopic galaxies binned in different luminosities and stellar masses. We estimated the systematics, e.g., selection bias, PSF reconstruction bias, PSF dilution bias, shear responsivity bias, and noise rectification bias, which in total is between −9.1% and 20.8% at 2 σ levels. The overall GG lensing signals we measured are in good agreement with Mandelbaum et al. The reduced χ {sup 2} between the two measurements in different luminosity bins are from 0.43 to 0.83. Larger reduced χ {sup 2} from 0.60 to 1.87 are seen for different stellar mass bins, which is mainly caused by the different stellar mass estimator. The results in this paper with higher signal-to-noise ratio are due to the larger survey area than SDSS DR4, confirming that more luminous/massive galaxies bear stronger GG lensing signals. We divide the foreground galaxies into red/blue and star-forming/quenched subsamples and measure their GG lensing signals. We find that, at a specific stellar mass/luminosity, the red/quenched galaxies have stronger GG lensing signals than their counterparts, especially at large radii. These GG lensing signals can be used to probe the galaxy–halo mass relations and their environmental dependences in the halo occupation or conditional luminosity function framework.

  2. Gravitationally lensed quasars in Gaia: I. Resolving small-separation lenses

    Science.gov (United States)

    Lemon, Cameron A.; Auger, Matthew W.; McMahon, Richard G.; Koposov, Sergey E.

    2017-12-01

    Gaia's exceptional resolution (FWHM ∼ 0.1 arcsec) allows identification and cataloguing of the multiple images of gravitationally lensed quasars. We investigate a sample of 49 known lensed quasars in the Sloan Digital Sky Survey (SDSS) footprint, with image separations less than 2 arcsec, and find that eight are detected with multiple components in the first Gaia data release. In the case of the 41 single Gaia detections, we generally are able to distinguish these lensed quasars from single quasars when comparing Gaia flux and position measurements to those of Pan-STARRS and SDSS. This is because the multiple images of these lensed quasars are typically blended in ground-based imaging and therefore the total flux and a flux-weighted centroid are measured, which can differ significantly from the fluxes and centroids of the individual components detected by Gaia. We compare the fluxes through an empirical fit of Pan-STARRS griz photometry to the wide optical Gaia bandpass values using a sample of isolated quasars. The positional offsets are calculated from a recalibrated astrometric SDSS catalogue. Applying flux and centroid difference criteria to spectroscopically confirmed quasars, we discover four new sub-arcsecond-separation lensed quasar candidates which have two distinct components of similar colour in archival Canada-France-Hawaii Telescope or Hyper Suprime Cam data. Our method based on single Gaia detections can be used to identify the ∼1400 lensed quasars with image separation above 0.5 arcsec, expected to have only one image bright enough to be detected by Gaia.

  3. GALAXY SCALE LENSES IN THE RCS2. I. FIRST CATALOG OF CANDIDATE STRONG LENSES

    International Nuclear Information System (INIS)

    Anguita, T.; Barrientos, L. F.; Gladders, M. D.; Faure, C.; Yee, H. K. C.; Gilbank, D. G.

    2012-01-01

    We present the first galaxy scale lens catalog from the second Red-Sequence Cluster Survey. The catalog contains 60 lensing system candidates comprised of Luminous Red Galaxy (LRG) lenses at 0.2 ∼ 11 [M ☉ h –1 ]) and rich in dark matter (M/L-bar∼ 14 [M ☉ /L ☉,B h]). Even though a slight increasing trend in the mass-to-light ratio is observed from z = 0.2 to z = 0.5, current redshift and light profile measurements do not allow stringent constraints on the mass-to-light ratio evolution of LRGs.

  4. [Current care and maintenance systems for contact lenses].

    Science.gov (United States)

    Lipener, César; Ray, Camila Baracat Mendina

    2008-01-01

    The proper maintenance of contact lenses is crucial for their success and to maintain the continuity of their use. Many patients abandon the use of their lenses due to problems that could be solved with relatively simple treatments. The misuse of lenses, coupled with poor adjustment, contamination, eye disease and environmental factors may increase the number of corneal infections through the proliferation of microorganisms. This article aims to provide contact lens care and maintenance updates.

  5. Plasma lenses for SLAC Final Focus Test facility

    International Nuclear Information System (INIS)

    Betz, D.; Cline, D.; Joshi, C.; Rajagopalan, S.; Rosenzweig, J.; Su, J.J.; Williams, R.; Chen, P.; Gundersen, M.; Katsouleas, T.; Norem, J.

    1991-01-01

    A collaborative group of accelerator and plasma physicists and engineers has formed with an interest in exploring the use of plasma lenses to meet the needs of future colliders. Analytic and computational models of plasma lenses are briefly reviewed and several design examples for the SLAC Final Focus Test Beam are presented. The examples include discrete, thick, and adiabatic lenses. A potential plasma source with desirable lens characteristics is presented

  6. Prospects for weak lensing studies with new radio telescopes

    OpenAIRE

    M. L. Brown

    2012-01-01

    I outline the prospects for performing weak lensing studies with the new generation of radio telescopes that are coming online now and in the future. I include a description of a proposed technique to use polarization observations in radio weak lensing analyses which could prove extremely useful for removing a contaminating signal from intrinsic alignments. Ultimately, the Square Kilometre Array promises to be an exceptional instrument for performing weak lensing studies due to the high resol...

  7. Phosphorylcholine and phosphorylethanolamine in human and rhesus monkey lenses.

    Science.gov (United States)

    Jernigan, H M; Zigler, J S

    1989-11-01

    Phosphorylcholine (P-choline) and phosphorylethanolamine (P-ethanolamine) are important precursors of phospholipids. The metabolism and concentration of P-choline has been shown to change in animal models of cataract, especially in oxidatively or osmotically stressed rat lenses. The concentrations of P-choline and P-ethanolamine were determined in monkey lenses and in normal and cataractous human lenses, and the rate of synthesis of P-choline was determined in human and monkey lenses. The concentration of P-choline in 53 clear human lenses was 0.94 mM (+/- 0.31 S.D.) and was relatively unaffected by age, eye bank storage, or freezing. There was a 70% decrease in P-choline in brown cataracts but no significant change from normal in non-brown cataracts. The concentration of P-ethanolamine in human lenses was 0.45 mM (+/- 0.26 S.D.), and it appeared to decrease during frozen storage of lenses and in cataracts. The concentrations of P-choline and P-ethanolamine in 12 rhesus monkey lenses were 1.51 mM (+/- 0.27 S.D.) and 0.75 mM (+/- 0.14 S.D.), respectively. The rate of synthesis of P-choline in monkey lenses incubated with [3H]choline was 8 nmol hr-1 g-1 wet weight in 1 mM choline. Adult human lenses incubated in 1 mM choline synthesized P-choline at a rate of 23 nmol hr-1 g-1 (+/- 6 S.D.). This limited capacity for P-choline synthesis in primate lenses may contribute to the lower P-choline concentration relative to rat lenses, which contain 11 mM P-choline and can synthesize P-choline at an apparent maximum rate of 130 nmol hr-1 g-1.

  8. HEK. VI. On the Dearth of Galilean Analogs in Kepler, and the Exomoon Candidate Kepler-1625b I

    Science.gov (United States)

    Teachey, A.; Kipping, D. M.; Schmitt, A. R.

    2018-01-01

    Exomoons represent an outstanding challenge in modern astronomy, with the potential to provide rich insights into planet formation theory and habitability. In this work, we stack the phase-folded transits of 284 viable moon hosting Kepler planetary candidates, in order to search for satellites. These planets range from Earth- to Jupiter-sized and from ∼0.1 to 1.0 au in separation—so-called “warm” planets. Our data processing includes two-pass harmonic detrending, transit timing variations, model selection, and careful data quality vetting to produce a grand light curve with an rms of 5.1 ppm. We find that the occurrence rate of Galilean analog moon systems for planets orbiting between ∼0.1 and 1.0 au can be constrained to be η population of short-period moons with radii ∼0.5 R ⊕ orbiting at 5–10 planetary radii. However, we stress that the low Bayes factor of just 2 in this region means it should be treated as no more than a hint at this time. Splitting our data into various physically motivated subsets reveals no strong signal. The dearth of Galilean analogs around warm planets places the first strong constraint on exomoon formation models to date. Finally, we report evidence for an exomoon candidate Kepler-1625b I, which we briefly describe ahead of scheduled observations of the target with the Hubble Space Telescope.

  9. Weak lensing of the Lyman-alpha forest

    Science.gov (United States)

    Croft, Rupert A. C.; Romeo, Alessandro; Metcalf, R. Benton

    2018-03-01

    The angular positions of quasars are deflected by the gravitational lensing effect of foreground matter. The Lyα forest seen in the spectra of these quasars is therefore also lensed. We propose that the signature of weak gravitional lensing of the Lyα forest could be measured using similar techniques that have been applied to the lensed Cosmic Microwave Background, and which have also been proposed for application to spectral data from 21cm radio telescopes. As with 21cm data, the forest has the advantage of spectral information, potentially yielding many lensed "slices" at different redshifts. We perform an illustrative idealized test, generating a high resolution angular grid of quasars (of order arcminute separation), and lensing the Lyα forest spectra at redshifts z = 2 - 3 using a foreground density field. We find that standard quadratic estimators can be used to reconstruct images of the foreground mass distribution at z ˜ 1. There currently exists a wealth of Lyα forest data from quasar and galaxy spectral surveys, with smaller sightline separations expected in the future. Lyα forest lensing is sensitive to the foreground mass distribution at redshifts intermediate between CMB lensing and galaxy shear, and avoids the difficulties of shape measurement associated with the latter. With further refinement and application of mass reconstruction techniques, weak gravitational lensing of the high redshift Lyα forest may become a useful new cosmological probe.

  10. Using Strong Gravitational Lensing to Identify Fossil Group Progenitors

    Science.gov (United States)

    Johnson, Lucas E.; Irwin, Jimmy A.; White, Raymond E., III; Wong, Ka-Wah; Maksym, W. Peter; Dupke, Renato A.; Miller, Eric D.; Carrasco, Eleazar R.

    2018-04-01

    Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.

  11. Contact lenses fitting after intracorneal ring segments implantation in keratoconus

    Directory of Open Access Journals (Sweden)

    Luciane Bugmann Moreira

    2013-08-01

    Full Text Available PURPOSE: Evaluate contact lenses fitting after intracorneal ring implantation for keratoconus, its visual acuity and comfort. METHODS: Retrospective study of patients undergoing contact lenses fitting, after intracorneal ring for keratoconus. The criterion for contact lens fitting was unsatisfactory visual acuity with spectacle correction as referred by the patients. All patients were intolerants to contact lenses prior to intracorneal implantation. Visual acuity analysis was done by conversion of Snellen to logMAR scales. The comfort was evaluated according subjective questioning of good, medium or poor comfort. RESULTS: Nineteen patients were included in the study. Two patients (10.5% did not achieved good comfort with contact lenses and underwent penetrating keratoplasties. All the others 17 patients showed good or medium comfort. Four rigid gas-permeable contact lenses were fitted, one piggyback approach, 3 toric soft contact lenses, 2 soft lenses specially design for keratoconus and 7 disposable soft lenses. The average visual acuity improved from 0.77 ± 0.37 to 0.19 ± 0.13 logMAR units after contact lenses fitting. CONCLUSION: Contact lens fitting after intracorneal ring is possible, provides good comfort, improves visual acuity, and therefore, may postpone the need for penetrating keratoplasty.

  12. Quantitative evaluation of performance of three-dimensional printed lenses

    Science.gov (United States)

    Gawedzinski, John; Pawlowski, Michal E.; Tkaczyk, Tomasz S.

    2017-08-01

    We present an analysis of the shape, surface quality, and imaging capabilities of custom three-dimensional (3-D) printed lenses. 3-D printing technology enables lens prototypes to be fabricated without restrictions on surface geometry. Thus, spherical, aspherical, and rotationally nonsymmetric lenses can be manufactured in an integrated production process. This technique serves as a noteworthy alternative to multistage, labor-intensive, abrasive processes, such as grinding, polishing, and diamond turning. Here, we evaluate the quality of lenses fabricated by Luxexcel using patented Printoptical©; technology that is based on an inkjet printing technique by comparing them to lenses made with traditional glass processing technologies (grinding, polishing, etc.). The surface geometry and roughness of the lenses were evaluated using white-light and Fizeau interferometers. We have compared peak-to-valley wavefront deviation, root mean square (RMS) wavefront error, radii of curvature, and the arithmetic roughness average (Ra) profile of plastic and glass lenses. In addition, the imaging performance of selected pairs of lenses was tested using 1951 USAF resolution target. The results indicate performance of 3-D printed optics that could be manufactured with surface roughness comparable to that of injection molded lenses (Ra<20 nm). The RMS wavefront error of 3-D printed prototypes was at a minimum 18.8 times larger than equivalent glass prototypes for a lens with a 12.7 mm clear aperture, but, when measured within 63% of its clear aperture, the 3-D printed components' RMS wavefront error was comparable to glass lenses.

  13. The Dynamics of Tightly-packed Planetary Systems in the Presence of an Outer Planet: Case Studies Using Kepler-11 and Kepler-90

    Science.gov (United States)

    Granados Contreras, A. P.; Boley, A. C.

    2018-03-01

    We explore the effects of an undetected outer giant planet on the dynamics, observability, and stability of Systems with Tightly-packed Inner Planets (STIPs). We use direct numerical simulations along with secular theory and synthetic secular frequency spectra to analyze how analogues of Kepler-11 and Kepler-90 behave in the presence of a nearly co-planar, Jupiter-like outer perturber with semimajor axes between 1 and 5.2 au. Most locations of the outer perturber do not affect the evolution of the inner planetary systems, apart from altering precession frequencies. However, there are locations at which an outer planet causes system instability due to, in part, secular eccentricity resonances. In Kepler-90, there is a range of orbital distances for which the outer perturber drives planets b and c, through secular interactions, onto orbits with inclinations that are ∼16° away from the rest of the planets. Kepler-90 is stable in this configuration. Such secular resonances can thus affect the observed multiplicity of transiting systems. We also compare the synthetic apsidal and nodal precession frequencies with the secular theory and find some misalignment between principal frequencies, indicative of strong interactions between the planets (consistent with the system showing TTVs). First-order libration angles are calculated to identify MMRs in the systems, for which two near-MMRs are shown in Kepler-90, with a 5:4 between b and c, as well as a 3:2 between g and h.

  14. Metal-Rich SX Phe Stars in the Kepler Field

    Directory of Open Access Journals (Sweden)

    Nemec James M.

    2015-01-01

    Full Text Available High-resolution spectroscopic observations have been made for 32 of the 34 candidate SX Phe stars identified in the Kepler field by Balona & Nemec (2012. All available long-and short-cadence Q0-Q17 Kepler photometry has been analyzed for the 34 candidates. Radial velocities (RVs, space motions (U, V, W, projected rotation velocities (υ sin i, spectral types, and atmospheric characteristics (Teff, log g, [M/H], υmic, etc. were derived from ~ 160 spectra taken with the ESPaDOnS spectrograph on the Canada-France-Hawaii 3.6-m telescope and with the ARCES spectrograph on the Apache Point Observatory 3.5-m telescope. Two thirds of the stars are fast rotators with υ sin i > 50 km/s, including four stars with υ sin i > 200 km/s. Three of the stars have (negative RVs > 250 km/s and retrograde space motions, and seven stars have total space motions > 400 km/s. All the spectroscopically measured SX Phe candidates have positions in a Toomre diagram that are consistent with being bona fide halo and thick-disk stars. Although several stars show a marked metal weakness, the mean [Fe/H] of the sample is near 0.0 dex (σ ~ 0.25 dex, which is considerably more metal-rich than is normally expected for a sample of Pop. II stars. Observed pulsation frequency modulations and optical time delays suggest that at least eight of the SX Phe stars are in binary systems, some of which show significant RV variations. Six of the time-delay binaries have secondary masses ranging from 0.05 to 0.70 M☉ and orbital periods in the range 9 to 1570 days. Another star appears to be an ellipsoidal variable with a 2.3-day orbital period; and two other systems have orbital periods longer than the ~ 4-year sampling interval of the Kepler data.

  15. KEPLER EXOPLANET CANDIDATE HOST STARS ARE PREFERENTIALLY METAL RICH

    International Nuclear Information System (INIS)

    Schlaufman, Kevin C.; Laughlin, Gregory

    2011-01-01

    We find that Kepler exoplanet candidate (EC) host stars are preferentially metal rich, including the low-mass stellar hosts of small-radius ECs. The last observation confirms a tentative hint that there is a correlation between the metallicity of low-mass stars and the presence of low-mass and small-radius exoplanets. In particular, we compare the J-H-g-r color-color distribution of Kepler EC host stars with a control sample of dwarf stars selected from the ∼150, 000 stars observed during Q1 and Q2 of the Kepler mission but with no detected planets. We find that at J - H = 0.30 characteristic of solar-type stars, the average g-r color of stars that host giant ECs is 4σ redder than the average color of the stars in the control sample. At the same J - H color, the average g-r color of solar-type stars that host small-radius ECs is indistinguishable from the average color of the stars in the control sample. In addition, we find that at J - H = 0.62 indicative of late K dwarfs, the average g-r color of stars that host small-radius ECs is 4σ redder than the average color of the stars in the control sample. These offsets are unlikely to be caused by differential reddening, age differences between the two populations, or the presence of giant stars in the control sample. Stellar models suggest that the first color offset is due to a 0.2 dex enhancement in [Fe/H] of the giant EC host population at M * ∼ 1 M sun , while Sloan photometry of M 67 and NGC 6791 suggests that the second color offset is due to a similar [Fe/H] enhancement of the small-radius EC host population at M * ∼ 0.7 M sun . These correlations are a natural consequence of the core-accretion model of planet formation.

  16. The search for ZZ Ceti stars in the original Kepler mission

    Science.gov (United States)

    Greiss, S.; Hermes, J. J.; Gänsicke, B. T.; Steeghs, D. T. H.; Bell, Keaton J.; Raddi, R.; Tremblay, P.-E.; Breedt, E.; Ramsay, G.; Koester, D.; Carter, P. J.; Vanderbosch, Z.; Winget, D. E.; Winget, K. I.

    2016-04-01

    We report the discovery of 42 white dwarfs in the original Kepler mission field, including nine new confirmed pulsating hydrogen-atmosphere white dwarfs (ZZ Ceti stars). Guided by the Kepler-Isaac Newton Telescope Survey, we selected white dwarf candidates on the basis of their U - g, g - r, and r - Hα photometric colours. We followed up these candidates with high-signal-to-noise optical spectroscopy from the 4.2-m William Herschel Telescope. Using ground-based, time series photometry, we put our sample of new spectroscopically characterized white dwarfs in the context of the empirical ZZ Ceti instability strip. Prior to our search, only two pulsating white dwarfs had been observed by Kepler. Ultimately, four of our new ZZ Cetis were observed from space. These rich data sets are helping initiate a rapid advancement in the asteroseismic investigation of pulsating white dwarfs, which continues with the extended Kepler mission, K2.

  17. A novel hybrid algorithm of GSA with Kepler algorithm for numerical optimization

    Directory of Open Access Journals (Sweden)

    Soroor Sarafrazi

    2015-07-01

    Full Text Available It is now well recognized that pure algorithms can be promisingly improved by hybridization with other techniques. One of the relatively new metaheuristic algorithms is Gravitational Search Algorithm (GSA which is based on the Newton laws. In this paper, to enhance the performance of GSA, a novel algorithm called “Kepler”, inspired by the astrophysics, is introduced. The Kepler algorithm is based on the principle of the first Kepler law. The hybridization of GSA and Kepler algorithm is an efficient approach to provide much stronger specialization in intensification and/or diversification. The performance of GSA–Kepler is evaluated by applying it to 14 benchmark functions with 20–1000 dimensions and the optimal approximation of linear system as a practical optimization problem. The results obtained reveal that the proposed hybrid algorithm is robust enough to optimize the benchmark functions and practical optimization problems.

  18. Lessons Learned from Developing and Operating the Kepler Science Pipeline and Building the TESS Science Pipeline

    Science.gov (United States)

    Jenkins, Jon M.

    2017-01-01

    The experience acquired through development, implementation and operation of the KeplerK2 science pipelines can provide lessons learned for the development of science pipelines for other missions such as NASA's Transiting Exoplanet Survey Satellite, and ESA's PLATO mission.

  19. Reconstructing the lensing mass in the Universe from photometric catalogue data

    NARCIS (Netherlands)

    Collett, Thomas E.; Marshall, Philip J.; Auger, Matthew W.; Hilbert, Stefan; Suyu, Sherry H.; Greene, Zachary; Treu, Tommaso; Fassnacht, Christopher D.; Koopmans, Leon V. E.; Bradac, Marusa; Blandford, Roger D.

    2013-01-01

    High precision cosmological distance measurements towards individual objects such as time delay gravitational lenses or Type Ia supernovae are affected by weak lensing perturbations by galaxies and groups along the line of sight. In time delay gravitational lenses, 'external convergence',

  20. Tevatron Electron Lenses: Design and Operation

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; /Fermilab; Bishofberger, Kip; /Los Alamos; Kamerdzhiev, Vsevolod; /Fermilab; Kozub, Sergei; /Serpukhov, IHEP; Kufer, Matthew; Kuznetsov, Gennady; Martinez, Alexander; Olson, Marvin; Pfeffer, Howard; Saewert, Greg; Scarpine, Vic; /Fermilab; Seryi, Andrei; /SLAC; Solyak, Nikolai; /Fermilab; Sytnik, Veniamin; /Serpukhov, IHEP; Tiunov, Mikhail; /Novosibirsk, IYF; Tkachenko, Leonid; /Serpukhov, IHEP; Wildman, David; Wolff, Daniel; Zhang, Xiao-Long; /Fermilab

    2011-09-12

    Fermilab's Tevatron is currently the world's highest energy accelerator in which tightly focused beams of 980 GeV protons and antiprotons collide at two dedicated interaction points (IPs). Both beams share the same beam pipe and magnet aperture and, in order to avoid multiple detrimental head-on collisions, the beams are placed on separated orbits everywhere except the main IPs by using high-voltage (HV) electrostatic separators. The electromagnetic beam-beam interaction at the main IPs together with the long-range interactions between separated beams adversely affect the collider performance, reducing the luminosity integral per store (period of continuous collisions) by 10-30%. Tuning the collider operation for optimal performance becomes more and more cumbersome as the beam intensities and luminosity increase. The long-range effects which (besides being nonlinear) vary from bunch to bunch are particularly hard to mitigate. A comprehensive review of the beam-beam effects in the Tevatron Collider Run II can be found in Ref. [1]. The beam-beam effects have been the dominating sources of beam loss and lifetime limitations in the Tevatron proton-antiproton collider [1]. Electron lenses were originally proposed for compensation of electromagnetic long-range and head-on beam-beam interactions of proton and antiproton beams [2]. Results of successful employment of two electron lenses built and installed in the Tevatron are reported in [3,4,5]. In this paper we present design features of the Tevatron electron lenses (TELs), discuss the generation of electron beams, describe different modes of operation and outline the technical parameters of various subsystems.

  1. Contact Lenses for Keratoconus- Current Practice

    Science.gov (United States)

    Moschos, Marilita M.; Nitoda, Eirini; Georgoudis, Panagiotis; Balidis, Miltos; Karageorgiadis, Eleftherios; Kozeis, Nikos

    2017-01-01

    Background: Keratoconus is a chronic, bilateral, usuallly asymmetrical, non-inflammatory, ectatic disorder, being characterized by progressive steepening, thinning and apical scarring of the cornea. Initially, the patient is asymptomatic, but the visual acuity gradually decreases, resulting in significant vision loss due to the development of irregular astigmatism, myopia, corneal thinning and scarring. The classic treatment of visual rehabilitation in keratoconus is based on spectacles and contact lenses (CLs). Objective: To summarize the types of CLs used in the treatment of keratoconus. This is literature review of several important published articles focusing on the visual rehabilitation in keratoconus with CLs. Method: Gas permeable (GP) CLs have been found to achieve better best corrected visual acuity than spectacles, eliminating 3rd-order coma root-mean-square (RMS) error, 3rd-order RMS, and higher-order RMS. However, they have implicated in reduction of corneal basal epithelial cell and anterior stromal keratocyte densities. Soft CLs seem to provide greater comfort and lower cost, but the low oxygen permeability (if the lens is not a silicone hydrogel), and the inability to mask moderate to severe irregular astigmatism are the main disadvantages of them. On the other hand, scleral CLs ensure stable platforms, which eliminate high-order aberrations and provide good centration and visual acuity. Their main disadvantages include the difficulties in application and removal of these lenses along with corneal flattening and swelling. Result: The modern hybrid CLs are indicated in cases of poor centration, poor stability or intolerance with GP lenses. Finally, piggyback CL systems effectively ameliorate visual acuity, but they have been related to corneal neovascularization and giant papillary conjunctivitis. Conclusion: CLs seem to rehabilitate visual performance, diminishing the power of the cylinder and the high-order aberrations. The final choice of CLs is

  2. Precision cluster mass determination from weak lensing

    Science.gov (United States)

    Mandelbaum, Rachel; Seljak, Uroš; Baldauf, Tobias; Smith, Robert E.

    2010-07-01

    Weak gravitational lensing has been used extensively in the past decade to constrain the masses of galaxy clusters, and is the most promising observational technique for providing the mass calibration necessary for precision cosmology with clusters. There are several challenges in estimating cluster masses, particularly (a) the sensitivity to astrophysical effects and observational systematics that modify the signal relative to the theoretical expectations, and (b) biases that can arise due to assumptions in the mass estimation method, such as the assumed radial profile of the cluster. All of these challenges are more problematic in the inner regions of the cluster, suggesting that their influence would ideally be suppressed for the purpose of mass estimation. However, at any given radius the differential surface density measured by lensing is sensitive to all mass within that radius, and the corrupted signal from the inner parts is spread out to all scales. We develop a new statistic Υ(RR0) that is ideal for estimation of cluster masses because it completely eliminates mass contributions below a chosen scale (which we suggest should be about 20 per cent of the virial radius), and thus reduces sensitivity to systematic and astrophysical effects. We use simulated and analytical profiles including shape noise to quantify systematic biases on the estimated masses for several standard methods of mass estimation, finding that these can lead to significant mass biases that range from 10 to over 50 per cent. The mass uncertainties when using the new statistic Υ(RR0) are reduced by up to a factor of 10 relative to the standard methods, while only moderately increasing the statistical errors. This new method of mass estimation will enable a higher level of precision in future science work with weak lensing mass estimates for galaxy clusters.

  3. Magnified Weak Lensing Cross Correlation Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Melville P., Clowe, Douglas I.

    2010-11-30

    This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60

  4. The lensing properties of the Einasto profile

    OpenAIRE

    Retana-Montenegro, E.; Frutos-Alfaro, F.

    2011-01-01

    In recent high resolution N-body CDM simulations, it has been had found that nonsingular three-parameter models, e.g. the Einasto profile has a better performance better than the singular two-parameter models, e.g. the Navarro, Frenk and White in the fitting of a wide range of dark matter halos. A problem with this profile is that the surface mass density is non-analytical for general values of the Einasto index. Therefore, its other lensing properties have the same problem. We obtain an exac...

  5. Realizable planar gradient-index solar lenses.

    Science.gov (United States)

    Kotsidas, Panagiotis; Modi, Vijay; Gordon, Jeffrey M

    2012-04-01

    The design of single element planar hemispherical gradient-index solar lenses that can accommodate the constraints of realistic materials and fabrication techniques are presented, and simulated with an extended and polychromatic solar source for concentrator photovoltaics at flux concentration values exceeding 1000 suns. The planar hemispherical far-field lens is created from a near-field unit magnification spherical gradient-index design, and illustrated with an f/1.40 square solar lens that allows lossless packing within a concentrator module.

  6. Vibrational microspectroscopy analysis of human lenses

    Science.gov (United States)

    Paluszkiewicz, C.; Piergies, N.; Sozańska, A.; Chaniecki, P.; Rękas, M.; Miszczyk, J.; Gajda, M.; Kwiatek, W. M.

    2018-01-01

    In this study we present vibrational analysis of healthy (non-affected by cataract) and cataractous human lenses by means of Raman and FTIR spectroscopy methods. The performed analysis provides complex information about the secondary structure of the proteins and conformational changes of the amino acid residues due to the formation of opacification of human lens. Briefly, the changes in the conformation of the Tyr and Trp residues and the protein secondary structure between the healthy and cataractous samples, were recognized. Moreover, the observed spectral pattern suggests that the process of cataract development does not occur uniformly over the entire volume of the lens.

  7. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  8. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  9. Validation and Initial Characterization of the Long-period Planet Kepler-1654 b

    Science.gov (United States)

    Beichman, C. A.; Giles, H. A. C.; Akeson, R.; Ciardi, D.; Christiansen, J.; Isaacson, H.; Marcy, G. M.; Sinukoff, E.; Greene, T.; Fortney, J. J.; Crossfield, I.; Hu, R.; Howard, A. W.; Petigura, E. A.; Knutson, H. A.

    2018-04-01

    Fewer than 20 transiting Kepler planets have periods longer than one year. Our early search of the Kepler light curves revealed one such system, Kepler-1654b (originally KIC 8410697b), which shows exactly two transit events and whose second transit occurred only five days before the failure of the second of two reaction wheels brought the primary Kepler mission to an end. A number of authors have also examined light curves from the Kepler mission searching for long-period planets and identified this candidate. Starting in 2014 September, we began an observational program of imaging, reconnaissance spectroscopy, and precision radial velocity (RV) measurements that confirm with a high degree of confidence that Kepler-1654b is a bona fide transiting planet orbiting a mature G5V star (T eff = 5580 K, [Fe/H] = ‑0.08) with a semimajor axis of 2.03 au, a period of 1047.84 days, and a radius of 0.82 ± 0.02 R Jup. RV measurements using Keck’s HIRES spectrometer obtained over 2.5 years set a limit to the planet’s mass of <0.5 (3σ) M Jup. The bulk density of the planet is similar to that of Saturn or possibly lower. We assess the suitability of temperate gas giants like Kepler-1654b for transit spectroscopy with the James Webb Space Telescope, as their relatively cold equilibrium temperatures (T pl ∼ 200 K) make them interesting from the standpoint of exoplanet atmospheric physics. Unfortunately, these low temperatures also make the atmospheric scale heights small and thus transmission spectroscopy challenging. Finally, the long time between transits can make scheduling JWST observations difficult—as is the case with Kepler-1654b.

  10. Kepler-424 b: A 'lonely' hot Jupiter that found A companion

    Energy Technology Data Exchange (ETDEWEB)

    Endl, Michael [McDonald Observatory, The University of Texas at Austin, Austin, TX 78712 (United States); Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Havel, Mathieu; Howell, Steve B.; Quintana, Elisa [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Buchhave, Lars A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Brugamyer, Erik [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Robertson, Paul [Department of Astronomy and Astrophysics, Center for Exoplanets and Habitable Worlds, Pennsylvania State University (United States); Cochran, William D.; MacQueen, Phillip J. [McDonald Observatory and Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Lucas, Phillip [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Fischer, Debra [Department of Astronomy, Yale University (United States); Ciardi, David R. [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-11-10

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be {sup l}onely{sup .} This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to υ Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M {sub ⊕}.

  11. The Derivation, Properties and Value of Kepler's Combined Differential Photometric Precision

    OpenAIRE

    Christiansen, Jessie L.; Jenkins, Jon M.; Barclay, Thomas S.; Burke, Christopher J.; Caldwell, Douglas A.; Clarke, Bruce D.; Li, Jie; Seader, Shawn; Smith, Jeffrey C.; Stumpe, Martin C.; Tenenbaum, Peter; Thompson, Susan E.; Twicken, Joseph D.; Van Cleve, Jeffrey

    2012-01-01

    The Kepler Mission is searching for Earth-size planets orbiting solar-like stars by simultaneously observing >160,000 stars to detect sequences of transit events in the photometric light curves. The Combined Differential Photometric Precision (CDPP) is the metric that defines the ease with which these weak terrestrial transit signatures can be detected. An understanding of CDPP is invaluable for evaluating the completeness of the Kepler survey and inferring the underlying planet population. T...

  12. Multiplicity and properties of Kepler planet candidates: High spatial imaging and RV studies*

    Directory of Open Access Journals (Sweden)

    Aceituno J.

    2013-04-01

    Full Text Available The Kepler space telescope is discovering thousands of new planet candidates. However, a follow up program is needed in order to reject false candidates and to fully characterize the bona-fide exoplanets. Our main aims are: 1./ Detect and analyze close companions inside the typical Kepler PSF to study if they are the responsible of the dim in the Kepler light curves, 2./ Study the change in the stellar and planetary parameters due to the presence of an unresolved object, 3./ Help to validate those Kepler Objects of Interest that do not present any object inside the Kepler PSF and 4./ Study the multiplicity rate in planet host candidates. Such a large sample of observed planet host candidates allows us to do statistics about the presence of close (visual or bounded companions to the harboring star. We present here Lucky Imaging observations for a total amount of 98 Kepler Objects of Interest. This technique is based on the acquisition of thousands of very short exposure time images. Then, a selection and combination of a small amount of the best quality frames provides a high resolution image with objects having a 0.1 arcsec PSF. We applied this technique to carry out observations in the Sloan i and Sloan z filters of our Kepler candidates. We find blended objects inside the Kepler PSF for a significant percentage of KOIs. On one hand, only 58.2% of the hosts do not present any object within 6 arcsec. On the other hand, we have found 19 companions closer than 3 arcsec in 17 KOIs. According to their magnitudes and i − z color, 8 of them could be physically bounded to the host star. We are also collecting high-spectral resolution spectroscopuy in order to derive the planet properties.

  13. CONSTRAINING THE RADIATION AND PLASMA ENVIRONMENT OF THE KEPLER CIRCUMBINARY HABITABLE-ZONE PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Zuluaga, Jorge I. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Mason, Paul A. [New Mexico State University—DACC, Las Cruces, NM 88003 (United States); Cuartas-Restrepo, Pablo A. [FACom—Instituto de Física—FCEN, Universidad de Antioquia, Calle 70 No. 52-21, Medellín (Colombia)

    2016-02-20

    The discovery of many planets using the Kepler telescope includes 10 planets orbiting eight binary stars. Three binaries, Kepler-16, Kepler-47, and Kepler-453, have at least one planet in the circumbinary habitable zone (BHZ). We constrain the level of high-energy radiation and the plasma environment in the BHZ of these systems. With this aim, BHZ limits in these Kepler binaries are calculated as a function of time, and the habitability lifetimes are estimated for hypothetical terrestrial planets and/or moons within the BHZ. With the time-dependent BHZ limits established, a self-consistent model is developed describing the evolution of stellar activity and radiation properties as proxies for stellar aggression toward planetary atmospheres. Modeling binary stellar rotation evolution, including the effect of tidal interaction between stars in binaries, is key to establishing the environment around these systems. We find that Kepler-16 and its binary analogs provide a plasma environment favorable for the survival of atmospheres of putative Mars-sized planets and exomoons. Tides have modified the rotation of the stars in Kepler-47, making its radiation environment less harsh in comparison to the solar system. This is a good example of the mechanism first proposed by Mason et al. Kepler-453 has an environment similar to that of the solar system with slightly better than Earth radiation conditions at the inner edge of the BHZ. These results can be reproduced and even reparameterized as stellar evolution and binary tidal models progress, using our online tool http://bhmcalc.net.

  14. Kepler: A Search for Terrestrial Planets - SOC 9.3 DR25 Pipeline Parameter Configuration Reports

    Science.gov (United States)

    Campbell, Jennifer R.

    2017-01-01

    This document describes the manner in which the pipeline and algorithm parameters for the Kepler Science Operations Center (SOC) science data processing pipeline were managed. This document is intended for scientists and software developers who wish to better understand the software design for the final Kepler codebase (SOC 9.3) and the effect of the software parameters on the Data Release (DR) 25 archival products.

  15. Handbook of satellite orbits from Kepler to GPS

    CERN Document Server

    Capderou, Michel

    2014-01-01

    Fifty years after Sputnik, artificial satellites have become indispensable monitors in many areas, such as economics, meteorology, telecommunications, navigation and remote sensing. The specific orbits are important for the proper functioning of the satellites. This book discusses the great variety of satellite orbits, both in shape (circular to highly elliptical) and properties (geostationary, Sun-synchronous, etc.). This volume starts with an introduction into geodesy. This is followed by a presentation of the fundamental equations of mechanics to explain and demonstrate the properties for all types of orbits. Numerous examples are included, obtained through IXION software developed by the author. The book also includes an exposition of the historical background that is necessary to help the reader understand the main stages of scientific thought from Kepler to GPS. This book is intended for researchers, teachers and students working in the field of satellite technology. Engineers, geographers and all those...

  16. A fitting LEGACY – modelling Kepler's best stars

    Directory of Open Access Journals (Sweden)

    Aarslev Magnus J.

    2017-01-01

    Full Text Available The LEGACY sample represents the best solar-like stars observed in the Kepler mission[5, 8]. The 66 stars in the sample are all on the main sequence or only slightly more evolved. They each have more than one year's observation data in short cadence, allowing for precise extraction of individual frequencies. Here we present model fits using a modified ASTFIT procedure employing two different near-surface-effect corrections, one by Christensen-Dalsgaard[4] and a newer correction proposed by Ball & Gizon[1]. We then compare the results obtained using the different corrections. We find that using the latter correction yields lower masses and significantly lower χ2 values for a large part of the sample.

  17. KEPLER-7b: A TRANSITING PLANET WITH UNUSUALLY LOW DENSITY

    International Nuclear Information System (INIS)

    Latham, David W.; Buchhave, Lars A.; Furesz, Gabor; Geary, John C.; Borucki, William J.; Koch, David G.; Lissauer, Jack J.; Rowe, Jason F.; Brown, Timothy M.; Basri, Gibor; Batalha, Natalie M.; Caldwell, Douglas A.; Jenkins, Jon M.; Cochran, William D.; Dunham, Edward W.; Gautier, Thomas N.; Gilliland, Ronald L.; Howell, Steve B.; Marcy, Geoffrey W.; Monet, David G.

    2010-01-01

    We report on the discovery and confirmation of Kepler-7b, a transiting planet with unusually low density. The mass is less than half that of Jupiter, M P = 0.43 M J , but the radius is 50% larger, R P = 1.48 R J . The resulting density, ρ P = 0.17 g cm -3 , is the second lowest reported so far for an extrasolar planet. The orbital period is fairly long, P = 4.886 days, and the host star is not much hotter than the Sun, T eff = 6000 K. However, it is more massive and considerably larger than the Sun, M * = 1.35 M sun and R * = 1.84 R sun , and must be near the end of its life on the main sequence.

  18. DISCOVERY OF THE TRANSITING PLANET KEPLER-5b

    International Nuclear Information System (INIS)

    Koch, David G.; Borucki, William J.; Rowe, Jason F.; Lissauer, Jack J.; Morrison, David; Batalha, Natalie M.; Brown, Timothy M.; Caldwell, Douglas A.; DeVore, Edna; Jenkins, Jon M.; Caldwell, John; Cochran, William D.; Dunham, Edward W.; Dupree, Andrea K.; Geary, John C.; Latham, David W.; Gautier, Thomas N.; Gilliland, Ron L.; Howell, Steve B.; Marcy, Geoff W.

    2010-01-01

    We present 44 days of high duty cycle, ultra precise photometry of the 13th magnitude star Kepler-5 (KIC 8191672, T eff = 6300 K, log g= 4.1), which exhibits periodic transits with a depth of 0.7%. Detailed modeling of the transit is consistent with a planetary companion with an orbital period of 3.548460 ± 0.000032 days and a radius of 1.431 +0.041 -0.052 R J . Follow-up radial velocity measurements with the Keck HIRES spectrograph on nine separate nights demonstrate that the planet is more than twice as massive as Jupiter with a mass of 2.114 +0.056 -0.059 M J and a mean density of 0.894 ± 0.079 g cm -3 .

  19. Searching for Circumprimary and Circumbinary Planets in Kepler Data

    Science.gov (United States)

    Haghighipour, Nader

    We propose to use the currently available data from the Kepler space telescope (specifically, variations in transit and eclipse timing) to detect planets in circumprimary and circumbinary orbits in binary star systems. The detection of planets in close binary stars during the past decade and the recent success of the Kepler space telescope in detecting planets in circumbinary orbits strongly suggest that planet formation in and around binary stars is robust and planets of variety of sizes may exist in dual-star systems. Given that approximately 60% of the main and pre-main sequence stars are in binaries, many of such planet-hosting dual-stars are expected to exist which naturally leads to several fundamental questions on the formation, characteristics, frequency, and habitability of their planets. However, the small number of the currently known planets in binary star systems (only 8) does not allow for arriving at statistically meaningful answers to these questions. The success of the Kepler space telescope in identifying more than 2300 planetary candidates (of which many may be in close dual-stars) and over 2100 eclipsing binaries has provided rich grounds for searching for planet-hosting binary stars and increasing the number of their planets. We propose to use the data from quarter 0 (Q0) to quarter 6 (Q6), to identify the signature(s) of planet(s) in and around binary stars by analyzing the variations in the times of planetary transit or the eclipses of the binary. We will use the transit timing variations of the +2300 planetary candidates for detecting stellar companions to their planet-hosting stars, and the eclipse timing variations of the +2100 binary star systems to detect circumbinary planets. We have developed a powerful algorithm dubbed as QATS that allows us to analyze eclipse and transit timing variations accurately and efficiently. To properly account for the frequency of planets in binary stars systems and comparing that with the frequency of

  20. Kepler Planets Tend to Have Siblings of the Same Size

    Science.gov (United States)

    Kohler, Susanna

    2017-11-01

    After 8.5 years of observations with the Kepler space observatory, weve discovered a large number of close-in, tightly-spaced, multiple-planet systems orbiting distant stars. In the process, weve learned a lot about the properties about these systems and discovered some unexpected behavior. A new study explores one of the properties that has surprised us: planets of the same size tend to live together.Orbital architectures for 25 of the authors multiplanet systems. The dots are sized according to the planets relative radii and colored according to mass. Planets of similar sizes and masses tend to live together in the same system. [Millholland et al. 2017]Ordering of SystemsFrom Keplers observations of extrasolar multiplanet systems, we have seen that the sizes of planets in a given system arent completely random. Systems that contain a large planet, for example, are more likely to contain additional large planets rather than additional planets of random size. So though there is a large spread in the radii weve observed for transiting exoplanets, the spread within any given multiplanet system tends to be much smaller.This odd behavior has led us to ask whether this clustering occurs not just for radius, but also for mass. Since the multiplanet systems discovered by Kepler most often contain super-Earths and mini-Neptunes, which have an extremely large spread in densities, the fact that two such planets have similar radii does not guarantee that they have similar masses.If planets dont cluster in mass within a system, this would raise the question of why planets coordinate only their radii within a given system. If they do cluster in mass, it implies that planets within the same system tend to have similar densities, potentially allowing us to predict the sizes and masses of planets we might find in a given system.Insight into MassesLed by NSF graduate research fellow Sarah Millholland, a team of scientists at Yale University used recently determined masses for

  1. A simple derivation of Kepler's laws without solving differential equations

    International Nuclear Information System (INIS)

    Provost, J-P; Bracco, C

    2009-01-01

    Proceeding like Newton with a discrete time approach of motion and a geometrical representation of velocity and acceleration, we obtain Kepler's laws without solving differential equations. The difficult part of Newton's work, when it calls for non-trivial properties of ellipses, is avoided by the introduction of polar coordinates. Then a simple reconsideration of Newton's figure naturally leads to an explicit expression of the velocity and to the equation of the trajectory. This derivation, which can be fully apprehended by undergraduates or by secondary school teachers (who might use it with their pupils), can be considered as a first application of mechanical concepts to a physical problem of great historical and pedagogical interest

  2. Beyond Kepler: Direct Imaging of Earth-like Planets

    Science.gov (United States)

    Belikov, Ruslan

    2012-01-01

    Is there another Earth out there? Is there life on it? People have been asking these questions for over two thousand years, and we finally stand on the verge of answering them. The Kepler space telescope is NASA's first mission designed to study Earthlike exoplanets (exo-Earths), and it will soon tell us how often exo-Earths occur in the habitable zones of their stars. The next natural step after Kepler is spectroscopic characterization of exo-Earths, which would tell us whether they possess an atmosphere, oxygen, liquid water, as well as other biomarkers. In order to do this, directly imaging an exo-Earth may be necessary (at least for Sun-like stars). Directly imaging an exo-Earth is challenging and likely requires a flagship-size optical space telescope with an unprecedented imaging system capable of achieving contrasts of 1(exp 10) very close to the diffraction limit. Several coronagraphs and external occulters have been proposed to meet this challenge and are in development. After first overviewing the history and current state of the field, my talk will focus on the work proceeding at the Ames Coronagraph Experiment (ACE) at the NASA Ames Research Center, where we are developing the Phase Induced Amplitude Apodization (PIAA) coronagraph in a collaboration with JPL. PIAA is a powerful technique with demonstrated aggressive performance that defines the state of the art at small inner working angles. At ACE, we have achieved contrasts of 2(exp -8) with an inner working angle of 2 lambda/D and 1(exp -6) at 1.4 lambda/D. On the path to exo-Earth imaging, we are also pursuing a smaller telescope concept called EXCEDE (EXoplanetary Circumstellar Environments and Disk Explorer), which was recently selected for technology development (Category III) by NASA's Explorer program. EXCEDE will do fundamental science on debris disks as well as serve as a technological and scientific pathfinder for an exo-Earth imaging mission.

  3. Quantitative estimates of the surface habitability of Kepler-452b

    Science.gov (United States)

    Silva, Laura; Vladilo, Giovanni; Murante, Giuseppe; Provenzale, Antonello

    2017-09-01

    Kepler-452b is currently the best example of an Earth-size planet in the habitable zone of a sun-like star, a type of planet whose number of detections is expected to increase in the future. Searching for biosignatures in the supposedly thin atmospheres of these planets is a challenging goal that requires a careful selection of the targets. Under the assumption of a rocky-dominated nature for Kepler-452b, we considered it as a test case to calculate a temperature-dependent habitability index, h050, designed to maximize the potential presence of biosignature-producing activity. The surface temperature has been computed for a broad range of climate factors using a climate model designed for terrestrial-type exoplanets. After fixing the planetary data according to the experimental results, we changed the surface gravity, CO2 abundance, surface pressure, orbital eccentricity, rotation period, axis obliquity and ocean fraction within the range of validity of our model. For most choices of parameters, we find habitable solutions with h050 > 0.2 only for CO2 partial pressure p_CO_2 ≲ 0.04 bar. At this limiting value of CO2 abundance, the planet is still habitable if the total pressure is p ≲ 2 bar. In all cases, the habitability drops for eccentricity e ≳ 0.3. Changes of rotation period and obliquity affect the habitability through their impact on the equator-pole temperature difference rather than on the mean global temperature. We calculated the variation of h050 resulting from the luminosity evolution of the host star for a wide range of input parameters. Only a small combination of parameters yields habitability-weighted lifetimes ≳2 Gyr, sufficiently long to develop atmospheric biosignatures still detectable at the present time.

  4. Planet Hunters, Undergraduate Research, and Detection of Extrasolar Planet Kepler-818 b

    Science.gov (United States)

    Baker, David; Crannell, Graham; Duncan, James; Hays, Aryn; Hendrix, Landon

    2017-01-01

    Detection of extrasolar planets provides an excellent research opportunity for undergraduate students. In Spring 2012, we searched for transiting extrasolar planets using Kepler spacecraft data in our Research Experience in Physics course at Austin College. Offered during the regular academic year, these Research Experience courses engage students in the scientific process, including proposal writing, paper submission, peer review, and oral presentations. Since 2004, over 190 undergraduate students have conducted authentic scientific research through Research Experience courses at Austin College.Zooniverse’s citizen science Planet Hunters web site offered an efficient method for rapid analysis of Kepler data. Light curves from over 5000 stars were analyzed, of which 2.3% showed planetary candidates already tagged by the Kepler team. Another 1.5% of the light curves suggested eclipsing binary stars, and 1.6% of the light curves had simulated planets for training purposes.One of the stars with possible planetary transits had not yet been listed as a planetary candidate. We reported possible transits for Kepler ID 4282872, which later was promoted to planetary candidate KOI-1325 in 2012 and confirmed to host extrasolar planet Kepler-818 b in 2016 (Morton et al. 2016). Kepler-818 b is a “hot Neptune” with period 10.04 days, flux decrease during transit ~0.4%, planetary radius 4.69 Earth radii, and semi-major axis 0.089 au.

  5. ROTATIONAL SYNCHRONIZATION MAY ENHANCE HABITABILITY FOR CIRCUMBINARY PLANETS: KEPLER BINARY CASE STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Paul A. [Department of Physics, University of Texas at El Paso, El Paso, TX 79968 (United States); Zuluaga, Jorge I.; Cuartas-Restrepo, Pablo A. [FACom-Instituto de Fisica-FCEN, Universidad de Antioquia, Calle 70 No. 52-21, Medellin (Colombia); Clark, Joni M. [Department of Mathematics and Physical Sciences, New Mexico State University-DACC, Las Cruces, NM 88003 (United States)

    2013-09-10

    We report a mechanism capable of reducing (or increasing) stellar activity in binary stars, thereby potentially enhancing (or destroying) circumbinary habitability. In single stars, stellar aggression toward planetary atmospheres causes mass-loss, which is especially detrimental for late-type stars, because habitable zones are very close and activity is long lasting. In binaries, tidal rotational breaking reduces magnetic activity, thus reducing harmful levels of X-ray and ultraviolet (XUV) radiation and stellar mass-loss that are able to erode planetary atmospheres. We study this mechanism for all confirmed circumbinary (p-type) planets. We find that main sequence twins provide minimal flux variation and in some cases improved environments if the stars rotationally synchronize within the first Gyr. Solar-like twins, like Kepler 34 and Kepler 35, provide low habitable zone XUV fluxes and stellar wind pressures. These wide, moist, habitable zones may potentially support multiple habitable planets. Solar-type stars with lower mass companions, like Kepler 47, allow for protected planets over a wide range of secondary masses and binary periods. Kepler 38 and related binaries are marginal cases. Kepler 64 and analogs have dramatically reduced stellar aggression due to synchronization of the primary, but are limited by the short lifetime. Kepler 16 appears to be inhospitable to planets due to extreme XUV flux. These results have important implications for estimates of the number of stellar systems containing habitable planets in the Galaxy and allow for the selection of binaries suitable for follow-up searches for habitable planets.

  6. Processing and Managing the Kepler Mission's Treasure Trove of Stellar and Exoplanet Data

    Science.gov (United States)

    Jenkins, Jon M.

    2016-01-01

    The Kepler telescope launched into orbit in March 2009, initiating NASAs first mission to discover Earth-size planets orbiting Sun-like stars. Kepler simultaneously collected data for 160,000 target stars at a time over its four-year mission, identifying over 4700 planet candidates, 2300 confirmed or validated planets, and over 2100 eclipsing binaries. While Kepler was designed to discover exoplanets, the long term, ultra- high photometric precision measurements it achieved made it a premier observational facility for stellar astrophysics, especially in the field of asteroseismology, and for variable stars, such as RR Lyraes. The Kepler Science Operations Center (SOC) was developed at NASA Ames Research Center to process the data acquired by Kepler from pixel-level calibrations all the way to identifying transiting planet signatures and subjecting them to a suite of diagnostic tests to establish or break confidence in their planetary nature. Detecting small, rocky planets transiting Sun-like stars presents a variety of daunting challenges, from achieving an unprecedented photometric precision of 20 parts per million (ppm) on 6.5-hour timescales, supporting the science operations, management, processing, and repeated reprocessing of the accumulating data stream. This paper describes how the design of the SOC meets these varied challenges, discusses the architecture of the SOC and how the SOC pipeline is operated and is run on the NAS Pleiades supercomputer, and summarizes the most important pipeline features addressing the multiple computational, image and signal processing challenges posed by Kepler.

  7. Planet Hunters. VI: An Independent Characterization of KOI-351 and Several Long Period Planet Candidates from the Kepler Archival Data

    OpenAIRE

    Schmitt, Joseph R.; Wang, Ji; Fischer, Debra A.; Jek, Kian J.; Moriarty, John C.; Boyajian, Tabetha S.; Schwamb, Megan E.; Lintott, Chris; Lynn, Stuart; Smith, Arfon M.; Parrish, Michael; Schawinski, Kevin; Simpson, Robert; LaCourse, Daryll; Omohundro, Mark R.

    2013-01-01

    We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlapped with Kepler Objects of Interest (KOIs) at the time of submission. We report the discovery of one more addition to the six planet candidate system around KOI 351 making it the only seven planet candidate system from Kepler. Additionally KOI 351 bears some resemblance to our own solar system with the inner five planets ranging fr...

  8. From Spheric to Aspheric Solid Polymer Lenses: A Review

    Directory of Open Access Journals (Sweden)

    Kuo-Yung Hung

    2011-01-01

    Full Text Available This paper presents a new approach in the use of MEMS technology to fabricate micro-optofluidic polymer solid lenses in order to achieve the desired profile, focal length, numerical aperture, and spot size. The resulting polymer solid lenses can be applied in optical data storage systems, imaging systems, and automated optical inspection systems. In order to meet the various needs of different applications, polymer solid lenses may have a spherical or aspherical shape. The method of fabricating polymer solid lenses is different from methods used to fabricate tunable lenses with variable focal length or needing an external control system to change the lens geometry. The current trend in polymer solid lenses is toward the fabrication of microlenses with a high numerical aperture, small clear aperture (<2 mm, and high transmittance. In this paper we focus on the use of thermal energy and electrostatic force in shaping the lens profile, including both spherical and aspherical lenses. In addition, the paper discusses how to fabricate a lens with a high numerical aperture of 0.6 using MEMS and also compares the optical characteristics of polymer lens materials, including SU-8, Norland Optical Adhesive (NOA, and cyclic olefin copolymer (COC. Finally, new concepts and applications related to micro-optofluidic lenses and polymer materials are also discussed.

  9. Shallow rainwater lenses in deltaic areas with saline seepage

    NARCIS (Netherlands)

    De Louw, Perry G.B.; Eeman, Sara; Siemon, Bernhard; Voortman, Bernard R.; Gunnink, Jan; Van Baaren, Esther S.; Oude Essink, Gualbert

    2011-01-01

    In deltaic areas with saline seepage, fresh water availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence

  10. Shallow rainwater lenses in deltaic areas with saline seepage

    NARCIS (Netherlands)

    Louw, de P.G.B.; Eeman, S.; Siemon, B.; `Voortman, B.R.; Gunnink, J.; Baaren, E.S.; Oude Essink, G.H.P.

    2011-01-01

    In deltaic areas with saline seepage, freshwater availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence and

  11. A dearth of dark matter in strong gravitational lenses

    NARCIS (Netherlands)

    Sanders, R. H.

    I show that the lensing masses of the Sloan Lens Advanced Camera Surveys sample of strong gravitational lenses are consistent with the stellar masses determined from population synthesis models using the Salpeter initial mass function. This is true in the context of both General Relativity and

  12. 30 CFR 18.66 - Tests of windows and lenses.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of windows and lenses. 18.66 Section 18... Tests § 18.66 Tests of windows and lenses. (a) Impact tests. A 4-pound cylindrical weight with a 1-inch-diameter hemispherical striking surface shall be dropped (free fall) to strike the window or lens in its...

  13. Gauge-invariant formalism of cosmological weak lensing

    Science.gov (United States)

    Yoo, Jaiyul; Grimm, Nastassia; Mitsou, Ermis; Amara, Adam; Refregier, Alexandre

    2018-04-01

    We present the gauge-invariant formalism of cosmological weak lensing, accounting for all the relativistic effects due to the scalar, vector, and tensor perturbations at the linear order. While the light propagation is fully described by the geodesic equation, the relation of the photon wavevector to the physical quantities requires the specification of the frames, where they are defined. By constructing the local tetrad bases at the observer and the source positions, we clarify the relation of the weak lensing observables such as the convergence, the shear, and the rotation to the physical size and shape defined in the source rest-frame and the observed angle and redshift measured in the observer rest-frame. Compared to the standard lensing formalism, additional relativistic effects contribute to all the lensing observables. We explicitly verify the gauge-invariance of the lensing observables and compare our results to previous work. In particular, we demonstrate that even in the presence of the vector and tensor perturbations, the physical rotation of the lensing observables vanishes at the linear order, while the tetrad basis rotates along the light propagation compared to a FRW coordinate. Though the latter is often used as a probe of primordial gravitational waves, the rotation of the tetrad basis is indeed not a physical observable. We further clarify its relation to the E-B decomposition in weak lensing. Our formalism provides a transparent and comprehensive perspective of cosmological weak lensing.

  14. Weak Weak Lensing : How Accurately Can Small Shears be Measured?

    NARCIS (Netherlands)

    Kuijken, K.

    2006-01-01

    Abstract: Now that weak lensing signals on the order of a percent are actively being searched for (cosmic shear, galaxy-galaxy lensing, large radii in clusters...) it is important to investigate how accurately weak shears can be determined. Many systematic effects are present, and need to be

  15. Biochemical analyses of lipids deposited on silicone hydrogel lenses

    Directory of Open Access Journals (Sweden)

    Shin Hatou

    2010-07-01

    Conclusions: The quantity of total lipid and cholesterol deposited on the 3 silicone hydrogel lenses tested did not differ. However, there were significant differences in the amounts of phospholipid deposited among the 3 silicone hydrogel lenses, of which clinical significance should be explored in the future study.

  16. Hybrid Contact Lenses for Visual Management of Patients after ...

    African Journals Online (AJOL)

    2018-04-04

    Apr 4, 2018 ... contact lenses for visual rehabilitation of postkeratoplasty patients. Materials and Methods: Twenty eyes of ... UCVA was 1.00 logarithm of the minimum angle of resolution (logMAR) which improved to 0.40 logMAR after ..... time as a measure of success of scleral lenses for patients with irregular astigmatism.

  17. Compound Refractive Lenses for Thermal Neutron Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gary, Charles K.

    2013-11-12

    This project designed and built compound refractive lenses (CRLs) that are able to focus, collimate and image using thermal neutrons. Neutrons are difficult to manipulate compared to visible light or even x rays; however, CRLs can provide a powerful tool for focusing, collimating and imaging neutrons. Previous neutron CRLs were limited to long focal lengths, small fields of view and poor resolution due to the materials available and manufacturing techniques. By demonstrating a fabrication method that can produce accurate, small features, we have already dramatically improved the focal length of thermal neutron CRLs, and the manufacture of Fresnel lens CRLs that greatly increases the collection area, and thus efficiency, of neutron CRLs. Unlike a single lens, a compound lens is a row of N lenslets that combine to produce an N-fold increase in the refraction of neutrons. While CRLs can be made from a variety of materials, we have chosen to mold Teflon lenses. Teflon has excellent neutron refraction, yet can be molded into nearly arbitrary shapes. We designed, fabricated and tested Teflon CRLs for neutrons. We demonstrated imaging at wavelengths as short as 1.26 ? with large fields of view and achieved resolution finer than 250 μm which is better than has been previously shown. We have also determined designs for Fresnel CRLs that will greatly improve performance.

  18. The theory of stochastic cosmological lensing

    Energy Technology Data Exchange (ETDEWEB)

    Fleury, Pierre; Uzan, Jean-Philippe [Institut d' Astrophysique de Paris, UMR 7095 du CNRS, 98 bis Bd Arago, 75014 Paris (France); Larena, Julien, E-mail: fleury@iap.fr, E-mail: j.larena@ru.ac.za, E-mail: uzan@iap.fr [Department of Mathematics, Rhodes University, Grahamstown 6140 (South Africa)

    2015-11-01

    On the scale of the light beams subtended by small sources, e.g. supernovae, matter cannot be accurately described as a fluid, which questions the applicability of standard cosmic lensing to those cases. In this article, we propose a new formalism to deal with small-scale lensing as a diffusion process: the Sachs and Jacobi equations governing the propagation of narrow light beams are treated as Langevin equations. We derive the associated Fokker-Planck-Kolmogorov equations, and use them to deduce general analytical results on the mean and dispersion of the angular distance. This formalism is applied to random Einstein-Straus Swiss-cheese models, allowing us to: (1) show an explicit example of the involved calculations; (2) check the validity of the method against both ray-tracing simulations and direct numerical integration of the Langevin equation. As a byproduct, we obtain a post-Kantowski-Dyer-Roeder approximation, accounting for the effect of tidal distortions on the angular distance, in excellent agreement with numerical results. Besides, the dispersion of the angular distance is correctly reproduced in some regimes.

  19. Engineering acoustic lenses with help from evolution

    Science.gov (United States)

    Ha˚Kansson, Andreas; Sánchez-Dehesa, José; Sánchis, Lorenzo

    2004-05-01

    Optimization engineering through evolutionary algorithms have proven to be very efficient, especially in hard problems containing a large set of optimization parameters. Like evolution this family of algorithms is able to tackle enormous complex problems with fairly simple means. Here, a simple genetic algorithm [J. H. Holland, Adaptation in Natural and Artificial Systems (Univ. of Michigan, Ann Arbor, 1975)] is used in conjunction with the multiple scattering theory [L. Sánchis et al., Phys. Rev. B 67, 035422 (2003)] to fabricate a new generation of acoustic devices based on a discrete number of cylindrical scatterers. In particular, acoustic lenses [F. Cervera et al., Phys. Rev. Lett. 88, 023902 (2002)] with flat surfaces have been designed to focus the sound in a fixed focal point for one or multiple frequencies. Each scatterer is carefully placed using the optimization method within the preset boundary conditions, to maximize the pressure contribution in the chosen focal spot. With this method acoustic lenses with very low f-numbers of the order 0.3 and with amplifications over 12 dB have been estimated using a reduced number of scatterers (~60). Preliminary results obtained from the experimental realization of the designed devices confirm our predictions.

  20. Probing neutrino masses with CMB lensing extraction

    International Nuclear Information System (INIS)

    Lesgourgues, Julien; Perotto, Laurence; Pastor, Sergio; Piat, Michel

    2006-01-01

    We evaluate the ability of future cosmic microwave background (CMB) experiments to measure the power spectrum of large scale structure using quadratic estimators of the weak lensing deflection field. We calculate the sensitivity of upcoming CMB experiments such as BICEP, QUaD, BRAIN, ClOVER and Planck to the nonzero total neutrino mass M ν indicated by current neutrino oscillation data. We find that these experiments greatly benefit from lensing extraction techniques, improving their one-sigma sensitivity to M ν by a factor of order four. The combination of data from Planck and the SAMPAN mini-satellite project would lead to σ(M ν )∼0.1 eV, while a value as small as σ(M ν )∼0.035 eV is within the reach of a space mission based on bolometers with a passively cooled 3-4 m aperture telescope, representative of the most ambitious projects currently under investigation. We show that our results are robust not only considering possible difficulties in subtracting astrophysical foregrounds from the primary CMB signal but also when the minimal cosmological model (Λ Mixed Dark Matter) is generalized in order to include a possible scalar tilt running, a constant equation-of-state parameter for the dark energy and/or extra relativistic degrees of freedom

  1. Gravitational lensing of gravitational waves from merging neutron star binaries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yun; Stebbins, Albert; Turner, Edwin L.

    1996-05-01

    We discuss the gravitational lensing of gravitational waves from merging neutron star binaries, in the context of advanced LIGO type gravitational wave detectors. We consider properties of the expected observational data with cut on the signal-to-noise ratio \\rho, i.e., \\rho>\\rho_0. An advanced LIGO should see unlensed inspiral events with a redshift distribution with cut-off at a redshift z_{\\rm max} < 1 for h \\leq 0.8. Any inspiral events detected at z>z_{\\rm max} should be lensed. We compute the expected total number of events which are present due to gravitational lensing and their redshift distribution for an advanced LIGO in a flat Universe. If the matter fraction in compact lenses is close to 10\\%, an advanced LIGO should see a few strongly lensed events per year with \\rho >5.

  2. [Quality of life in patients wearing scleral lenses].

    Science.gov (United States)

    Picot, C; Gauthier, A-S; Campolmi, N; Delbosc, B

    2015-09-01

    To evaluate the contribution of scleral lenses in terms of improving the quality of life in the treatment of astigmatism after penetrating keratoplasty or in keratoconus. We conducted an observational retrospective study, evaluating quality of life (QOL) of patients who failed to adapt to RPG lenses, fitted with SPOT(®) scleral lenses between October 2007 and March 2011 in the University Hospital of Besançon Department of Ophthalmology. QOL was assessed before and after scleral lens adaptation with the French version of the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ 25). We included 47 patients (83 eyes) fitted with scleral lenses on one or both eyes: 56 eyes with keratoconus and 27 post-keratoplasty eyes. The average duration of wearing scleral lenses was 18±10months and the average wearing time was 14±3hours per day. The rate of participation in the survey was 86.5% (41 patients). Visual acuity in the better eye progressed from 0.68±0.46 to 0.15±0.17 logMAR at the 6th month after scleral lens adaptation (Pscleral lenses for at least 6 months were significantly higher than those without scleral lenses, with a global score of 80.2/100 with, versus 48.1/100 without, scleral lenses (P0.05). Scleral lenses showed a significant improvement in quality of life for patients who had failed or are intolerant to conventional rigid gas permeable contact lenses. In our two main optical indications, keratoconus and keratoplasty, they represent an alternative or a step prior to surgery. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  3. Modeling Kepler Transit Light Curves as False Positives: Rejection of Blend Scenarios for Kepler-9, and Validation of Kepler-9 d, a Super-Earth-Size Planet in a Multiple System

    Science.gov (United States)

    Torres, Guillermo; Fressin, Francois; Batalha, Natalie M.; Borucki, William J.; Brown, Timothy M.; Bryson, Stephen T.; Buchhave, Lars A.; Charbonneau, David; Ciardi, David R.; Dunham, Edward W.; hide

    2011-01-01

    Light curves from the Kepler Mission contain valuable information on the nature of the phenomena producing the transit-like signals. To assist in exploring the possibility that they are due to an astrophysical false positive we describe a procedure (BLENDER) to model the photometry in terms of a blend rather than a planet orbiting a star. A blend may consist of a background or foreground eclipsing binary (or star-planet pair) whose eclipses are attenuated by the light of the candidate and possibly other stars within the photometric aperture. We apply BLENDER to the case of Kepler-9 (KIC 3323887), a target harboring two previously confirmed Saturn-size planets (Kepler-9 b and Kepler-9 c) showing transit timing variations, and an additional shallower signal with a 1.59 day period suggesting the presence of a super-Earth-size planet. Using BLENDER together with constraints from other follow-up observations we are able to rule out all blends for the two deeper signals and provide independent validation of their planetary nature. For the shallower signal, we rule out a large fraction of the false positives that might mimic the transits. The false alarm rate for remaining blends depends in part (and inversely) on the unknown frequency of small-size planets. Based on several realistic estimates of this frequency, we conclude with very high confidence that this small signal is due to a super-Earth-size planet (Kepler-9 d) in a multiple system, rather than a false positive. The radius is determined to be 1.64(exp)(sub-14),R, and current spectroscopic observations are as yet insufficient to establish its mass.

  4. A simple technique of intraocular lenses explantation for single-piece foldable lenses

    Directory of Open Access Journals (Sweden)

    Arup Bhaumik

    2017-01-01

    Full Text Available Foldable intraocular lenses (IOLs are most commonly used in modern-day cataract surgery. Explantation of these IOLs is not frequently encountered, but sometimes extreme situations may demand the same. Commonly explantation is achieved by bisecting the IOL inside the anterior chamber with a cutter and delivering the pieces out one by one. This may require corneal wound extension with associated damage and endothelial loss leading to visual deterioration. We devised a simple, innovative IOL explantation technique utilizing a modified Alcon A cartridge and snare. This can successfully refold the IOL to be explanted inside the eye and deliver it out through the same wound. The device has limitations with very thick optic lenses, multipiece, and silicon IOLs. In conclusion, we describe a simple, innovative, and reproducible technique to explant almost any single piece IOL without compromising the original surgery and yielding very satisfactory outcomes.

  5. Kepler Planet Detection Metrics: Per-Target Detection Contours for Data Release 25

    Science.gov (United States)

    Burke, Christopher J.; Catanzarite, Joseph

    2017-01-01

    A necessary input to planet occurrence calculations is an accurate model for the pipeline completeness (Burke et al., 2015). This document describes the use of the Kepler planet occurrence rate products in order to calculate a per-target detection contour for the measured Data Release 25 (DR25) pipeline performance. A per-target detection contour measures for a given combination of orbital period, Porb, and planet radius, Rp, what fraction of transit signals are recoverable by the Kepler pipeline (Twicken et al., 2016; Jenkins et al., 2017). The steps for calculating a detection contour follow the procedure outlined in Burke et al. (2015), but have been updated to provide improved accuracy enabled by the substantially larger database of transit injection and recovery tests that were performed on the final version (i.e., SOC 9.3) of the Kepler pipeline (Christiansen, 2017; Burke Catanzarite, 2017a). In the following sections, we describe the main inputs to the per-target detection contour and provide a worked example of the python software released with this document (Kepler Planet Occurrence Rate Tools KeplerPORTs)1 that illustrates the generation of a detection contour in practice. As background material for this document and its nomenclature, we recommend the reader be familiar with the previous method of calculating a detection contour (Section 2 of Burke et al.,2015), input parameters relevant for describing the data quantity and quality of Kepler targets (Burke Catanzarite, 2017b), and the extensive new transit injection and recovery tests of the Kepler pipeline (Christiansen et al., 2016; Burke Catanzarite, 2017a; Christiansen, 2017).

  6. Increasing the sensitivity of the Kepler legacy archive to transiting planets

    Science.gov (United States)

    Still, Martin D.

    2014-01-01

    All legacy light curves archived by the Kepler project are available to the community. They are based upon simple aperture extractions from time-tagged pixel data. We demonstrate that this photometry method works well for the bright end of the Kepler target sample yet there is enormous scope for further gains in sensitivity to planet transits of faint stars in the sample. To this end, all pixel data have been made available in the archive. Methods for the user community to optimize aperture photometry and exploit point spread function modeling are being developed. Exploiting existing Kepler planet candidates, we showcase the signal-to-noise to be gained by these methods. We argue that at the faintest end of the candidate distribution, optimization provides a factor two improvement in sensitivity to transits, reaching the signal-to-noise promised by the eight year mission, curtailed by reaction wheel failure after four years. These methods can provide potentially significant improvement to a number of facets of the Kepler mission: 1. Sensitivity to new planet candidates residing currently below the signal-to-noise detection threshold; 2. Characterizing known transit profiles to higher precision; 3. Identifying contamination from nearby sources and removing contamination bias from transit depths; 4. Mitigating focus and pointing systematics within the Kepler data, and 5. Allowing the direct characterization of time-dependent physical and detector biases within the image background. With exisiting focal plane calibrations, the number of targets that currently benefit from optimized photometry is relatively small, limited to sources of magnitude Kp > 16. However, with additional refinement of the focal plane calibration, improvement in light curve quality for objects 14 < Kp < 16 can be anticipated, impacting 50% of the Kepler target sample. These methods are equally applicable to data from the upcoming TESS mission and are potentially a critical component to the

  7. GALAXY SCALE LENSES IN THE RCS2. I. FIRST CATALOG OF CANDIDATE STRONG LENSES

    Energy Technology Data Exchange (ETDEWEB)

    Anguita, T. [Centro de Astro-Ingenieria, Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago (Chile); Barrientos, L. F. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago (Chile); Gladders, M. D. [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States); Faure, C. [Laboratoire d' Astrophysique, Ecole Polytechnique Federale de Lausanne (EPFL), Obervatoire de Sauverny, CH-1290 Versoix (Switzerland); Yee, H. K. C.; Gilbank, D. G. [Department of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto, Ontario, M5S 3H4 (Canada)

    2012-04-01

    We present the first galaxy scale lens catalog from the second Red-Sequence Cluster Survey. The catalog contains 60 lensing system candidates comprised of Luminous Red Galaxy (LRG) lenses at 0.2 {approx}< z {approx}< 0.5 surrounded by blue arcs or apparent multiple images of background sources. The catalog is a valuable complement to previous galaxy-galaxy lens catalogs as it samples an intermediate lens redshift range and is composed of bright sources and lenses that allow easy follow-up for detailed analysis. Mass and mass-to-light ratio estimates reveal that the lens galaxies are massive ( M-bar {approx} 5.5 Multiplication-Sign 10{sup 11} [M{sub Sun} h{sup -1}]) and rich in dark matter (M/L-bar{approx} 14 [M{sub Sun }/L{sub Sun ,B} h]). Even though a slight increasing trend in the mass-to-light ratio is observed from z = 0.2 to z = 0.5, current redshift and light profile measurements do not allow stringent constraints on the mass-to-light ratio evolution of LRGs.

  8. Lensing and dynamics in two simple steps

    Science.gov (United States)

    Agnello, A.; Auger, M. W.; Evans, N. W.

    2013-02-01

    We present a ready-to-use method to constrain the density distribution in spherically symmetric early-type galaxy lenses. Assuming a power-law density profile, then joint use of the virial theorem and the lens equation yields simple formulae for the power-law index (or logarithmic density gradient). Any dependence on orbital anisotropy can be tightly constrained or even erased completely. Our results rely just on surface brightnesses and line-of-sight kinematics, making deprojection unnecessary. We revisit three systems that have already been examined in the literature (the Cosmic Horseshoe, the Jackpot and B1608+656) and provide our estimates. Finally, we show that the method yields a good approximation for the density profile even when the true profile is a broken power law, albeit with a mild bias towards isothermality.

  9. Weak lensing galaxy cluster field reconstruction

    Science.gov (United States)

    Jullo, E.; Pires, S.; Jauzac, M.; Kneib, J.-P.

    2014-02-01

    In this paper, we compare three methods to reconstruct galaxy cluster density fields with weak lensing data. The first method called FLens integrates an inpainting concept to invert the shear field with possible gaps, and a multi-scale entropy denoising procedure to remove the noise contained in the final reconstruction, that arises mostly from the random intrinsic shape of the galaxies. The second and third methods are based on a model of the density field made of a multi-scale grid of radial basis functions. In one case, the model parameters are computed with a linear inversion involving a singular value decomposition (SVD). In the other case, the model parameters are estimated using a Bayesian Monte Carlo Markov Chain optimization implemented in the lensing software LENSTOOL. Methods are compared on simulated data with varying galaxy density fields. We pay particular attention to the errors estimated with resampling. We find the multi-scale grid model optimized with Monte Carlo Markov Chain to provide the best results, but at high computational cost, especially when considering resampling. The SVD method is much faster but yields noisy maps, although this can be mitigated with resampling. The FLens method is a good compromise with fast computation, high signal-to-noise ratio reconstruction, but lower resolution maps. All three methods are applied to the MACS J0717+3745 galaxy cluster field, and reveal the filamentary structure discovered in Jauzac et al. We conclude that sensitive priors can help to get high signal-to-noise ratio, and unbiased reconstructions.

  10. Fitting miniscleral contact lenses in Korean patients with keratoconus.

    Science.gov (United States)

    Kim, Sujin; Lee, Jong Soo; Park, Young Kee; Lee, Seung Uk; Park, Young Min; Lee, Jong Heon; Lee, Ji-Eun

    2017-07-01

    The aim was to evaluate the clinical results of fitting MSD miniscleral contact lenses (MSD; Happy Vision Corp, Anyang, Korea) in Korean patients with keratoconus. This report presents a retrospective case review of 38 keratoconic patients fitted with MSD lenses. Visual acuity, comfort, mean wear time, final lens parameters, relationships between sagittal depth and topographic indices, success rate with the first lens ordered and adverse events were documented. The mean logMAR visual acuity was improved from 0.85 ± 0.78 with glasses and 0.28 ± 0.29 with corneal rigid gas-permeable lenses to 0.10 ± 0.11 with miniscleral contact lenses. Ninety-seven per cent of patients found the miniscleral contact lenses to be comfortable and the mean daily wear time was 10.1 ± 2.3 hours. The mean sagittal depth was 4.70 ± 0.35 mm and there was no correlation between sagittal depth and topographic indices. An average of 3.4 trial lenses was needed to decide the ordered lens and 1.3 ordered lenses to achieve the optimal fitting. One patient discontinued the wear of the lenses after three months due to discomfort. The use of MSD miniscleral contact lenses is a good alternative for patients with keratoconus and for those who failed to respond to other types of lens rehabilitation that results in both successful visual outcome and comfort. © 2016 Optometry Australia.

  11. Effects of refrigeration on daily microbial bioburden of hydrogel lenses.

    Science.gov (United States)

    Lapple, W J; Snyder, A C; Tuovinen, O H

    1987-03-01

    Microbial bioburden of contact lenses was evaluated in connection with lens care by refrigeration. Subjects wore new hydrogel contact lenses for approximately 8 hours. The microbial bioburden initially and after an overnight refrigeration of the lens was evaluated with the use of viable counts on three different media. No major changes in viable counts were observed resulting from this method of storage. Scanning electron microscopy indicated the presence of foreign material on both new and worn lenses, presumed to be debris from lens manufacture and mucoid deposits from daily wear. Microbial colonization was not apparent and single bacterial cells could not be discerned on the micrographs.

  12. [Implantation of intraocular lenses. Bullous keratopathy in pseudophakos].

    Science.gov (United States)

    Alberth, B

    1982-09-01

    The author presents his views on the implantation of intraocular lenses, in connection with two pseudophakic bullous keratopathy cases. There is no medical indication for implantation. The question is whether the most important function of the eye, object vision, may be risked in order to avoid aniseikonia or to restore binocular vision? Knowing that vision can be restored with glasses or contact lenses, is it ethical to induce more or less severe postoperative complications by means of intraocular lenses? In view of the considerable success often achieved immediately after the operation, complications which may not arise years later should also be taken into consideration.

  13. A SEARCH FOR LOST PLANETS IN THE KEPLER MULTI-PLANET SYSTEMS AND THE DISCOVERY OF A LONG PERIOD, NEPTUNE-SIZED EXOPLANET KEPLER-150 F.

    Science.gov (United States)

    Schmitt, Joseph R; Jenkins, Jon M; Fischer, Debra A

    2017-04-01

    The vast majority of the 4700 confirmed planets and planet candidates discovered by the Kepler space telescope were first found by the Kepler pipeline. In the pipeline, after a transit signal is found, all data points associated with those transits are removed, creating a "Swiss cheese"-like light curve full of holes, which is then used for subsequent transit searches. These holes could render an additional planet undetectable (or "lost"). We examine a sample of 114 stars with 3+ confirmed planets to see the effect that this "Swiss cheesing" may have. A simulation determined that the probability that a transiting planet is lost due to the transit masking is low, but non-neglible, reaching a plateau at ~3.3% lost in the period range of P = 400 - 500 days. We then model the transits in all quarters of each star and subtract out the transit signals, restoring the in-transit data points, and use the Kepler pipeline to search the transit-subtracted (i.e., transit-cleaned) light curves. However, the pipeline did not discover any credible new transit signals. This demonstrates the validity and robustness of the Kepler pipeline's choice to use transit masking over transit subtraction. However, a follow-up visual search through all the transit-subtracted data, which allows for easier visual identification of new transits, revealed the existence of a new, Neptune-sized exoplanet. Kepler-150 f ( P = 637.2 days, R P = 3.86 R ⊕ ) is confirmed using a combination of false positive probability analysis, transit duration analysis, and the planet multiplicity argument.

  14. A SEMI-ANALYTICAL MODEL OF VISIBLE-WAVELENGTH PHASE CURVES OF EXOPLANETS AND APPLICATIONS TO KEPLER- 7 B AND KEPLER- 10 B

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Renyu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Demory, Brice-Olivier [Astrophysics Group, Cavendish Laboratory, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Seager, Sara; Lewis, Nikole [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Showman, Adam P., E-mail: renyu.hu@jpl.nasa.gov [Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721 (United States)

    2015-03-20

    Kepler has detected numerous exoplanet transits by measuring stellar light in a single visible-wavelength band. In addition to detection, the precise photometry provides phase curves of exoplanets, which can be used to study the dynamic processes on these planets. However, the interpretation of these observations can be complicated by the fact that visible-wavelength phase curves can represent both thermal emission and scattering from the planets. Here we present a semi-analytical model framework that can be applied to study Kepler and future visible-wavelength phase curve observations of exoplanets. The model efficiently computes reflection and thermal emission components for both rocky and gaseous planets, considering both homogeneous and inhomogeneous surfaces or atmospheres. We analyze the phase curves of the gaseous planet Kepler- 7 b and the rocky planet Kepler- 10 b using the model. In general, we find that a hot exoplanet’s visible-wavelength phase curve having a significant phase offset can usually be explained by two classes of solutions: one class requires a thermal hot spot shifted to one side of the substellar point, and the other class requires reflective clouds concentrated on the same side of the substellar point. Particularly for Kepler- 7 b, reflective clouds located on the west side of the substellar point can best explain its phase curve. The reflectivity of the clear part of the atmosphere should be less than 7% and that of the cloudy part should be greater than 80%, and the cloud boundary should be located at 11° ± 3° to the west of the substellar point. We suggest single-band photometry surveys could yield valuable information on exoplanet atmospheres and surfaces.

  15. Identifying Exoplanets with Deep Learning: A Five-planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90

    Science.gov (United States)

    Shallue, Christopher J.; Vanderburg, Andrew

    2018-02-01

    NASA’s Kepler Space Telescope was designed to determine the frequency of Earth-sized planets orbiting Sun-like stars, but these planets are on the very edge of the mission’s detection sensitivity. Accurately determining the occurrence rate of these planets will require automatically and accurately assessing the likelihood that individual candidates are indeed planets, even at low signal-to-noise ratios. We present a method for classifying potential planet signals using deep learning, a class of machine learning algorithms that have recently become state-of-the-art in a wide variety of tasks. We train a deep convolutional neural network to predict whether a given signal is a transiting exoplanet or a false positive caused by astrophysical or instrumental phenomena. Our model is highly effective at ranking individual candidates by the likelihood that they are indeed planets: 98.8% of the time it ranks plausible planet signals higher than false-positive signals in our test set. We apply our model to a new set of candidate signals that we identified in a search of known Kepler multi-planet systems. We statistically validate two new planets that are identified with high confidence by our model. One of these planets is part of a five-planet resonant chain around Kepler-80, with an orbital period closely matching the prediction by three-body Laplace relations. The other planet orbits Kepler-90, a star that was previously known to host seven transiting planets. Our discovery of an eighth planet brings Kepler-90 into a tie with our Sun as the star known to host the most planets.

  16. KEPLER-68: THREE PLANETS, ONE WITH A DENSITY BETWEEN THAT OF EARTH AND ICE GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Gilliland, Ronald L. [Department of Astronomy, and Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Marcy, Geoffrey W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Rowe, Jason F.; Henze, Christopher E.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Rogers, Leslie [California Institute of Technology, Pasadena, CA 91125 (United States); Torres, Guillermo; Fressin, Francois; Desert, Jean-Michel [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lopez, Eric D. [University of California, Santa Cruz, CA 95064 (United States); Buchhave, Lars A. [Niels Bohr Institute, Copenhagen University (Denmark); Christensen-Dalsgaard, Jorgen; Handberg, Rasmus [Stellar Astrophysics Centre, Department of Physics and Astronomy, DK-8000 Aarhus C (Denmark); Jenkins, Jon M. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Chaplin, William J.; Elsworth, Yvonne [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Basu, Sarbani [Department of Astronomy, Yale University, 260 Whitney Ave., New Haven, CT 06511 (United States); Metcalfe, Travis S. [White Dwarf Research Corporation, Boulder, CO 80301 (United States); Hekker, Saskia, E-mail: gillil@stsci.edu [Astronomical Institute Anton Pannekoek, University of Amsterdam, 1098 XH Amsterdam, Science Park 904 (Netherlands); and others

    2013-03-20

    NASA's Kepler Mission has revealed two transiting planets orbiting Kepler-68. Follow-up Doppler measurements have established the mass of the innermost planet and revealed a third Jovian-mass planet orbiting beyond the two transiting planets. Kepler-68b, in a 5.4 day orbit, has M{sub P}=8.3{sup +2.2}{sub -2.4} M{sub Circled-Plus }, R{sub P}=2.31{sup +0.06}{sub -0.09} R{sub Circled-Plus }, and {rho}{sub P}=3.32{sup +0.86}{sub -0.98} g cm{sup -3}, giving Kepler-68b a density intermediate between that of the ice giants and Earth. Kepler-68c is Earth-sized, with a radius R{sub P}=0.953{sup +0.037}{sub -0.042} R{sub Circled-Plus} and transits on a 9.6 day orbit; validation of Kepler-68c posed unique challenges. Kepler-68d has an orbital period of 580 {+-} 15 days and a minimum mass of M{sub P}sin i = 0.947 {+-} 0.035M{sub J} . Power spectra of the Kepler photometry at one minute cadence exhibit a rich and strong set of asteroseismic pulsation modes enabling detailed analysis of the stellar interior. Spectroscopy of the star coupled with asteroseismic modeling of the multiple pulsation modes yield precise measurements of stellar properties, notably T{sub eff} = 5793 {+-} 74 K, M{sub *} = 1.079 {+-} 0.051 M{sub Sun }, R{sub *} = 1.243 {+-} 0.019 R{sub Sun }, and {rho}{sub *} = 0.7903 {+-} 0.0054 g cm{sup -3}, all measured with fractional uncertainties of only a few percent. Models of Kepler-68b suggest that it is likely composed of rock and water, or has a H and He envelope to yield its density {approx}3 g cm{sup -3}.

  17. Kepler Stellar Properties Catalog Update for Q1-Q17 DR25 Transit Search

    Science.gov (United States)

    Mathur, Savita; Huber, Daniel

    2016-01-01

    Huber et al. (2014) presented revised stellar properties for 196,468 Kepler targets, which were used for the Q1-Q16 TPSDV planet search (Tenenbaum et al. 2014). The catalog was based on atmospheric properties (i.e., temperature (Teff), surface gravity (log(g)), and metallicity ([FeH])) published in the literature using a variety of methods (e.g., asteroseismology, spectroscopy, exoplanet transits, photometry), which were then homogeneously fitted to a grid of Dartmouth (DSEP) isochrones (Dotter et al. 2008). The catalog was updated in early 2015 for the Q1-Q17 Data Release (DR) 24 transit search (Seader et al. 2015) based on the latest classifications of Kepler targets in the literature at that time. The methodology followed Huber et al. (2014). Here we provide updated stellar properties of 197,096 Kepler targets. Like the previous catalog, this update is based on atmospheric properties that were either published in the literature or provided by the Kepler community follow-up program (CFOP). The input values again come from different methods: asteroseismology, spectroscopy, flicker, and photometry. This catalog update was developed to support the SOC 9.3 TPSDV planet search (Twicken et al. 2016), which is expected to be the final search and data release by the Kepler project.In this document, we describe the method and the inputs that were used to build the catalog. The methodology follows Huber et al. (2014) with a few improvements as described in Section 2.

  18. High-resolution multi-band imaging for validation and characterization of small Kepler planets

    International Nuclear Information System (INIS)

    Everett, Mark E.; Silva, David R.; Barclay, Thomas; Howell, Steve B.; Ciardi, David R.; Horch, Elliott P.; Crepp, Justin R.

    2015-01-01

    High-resolution ground-based optical speckle and near-infrared adaptive optics images are taken to search for stars in close angular proximity to host stars of candidate planets identified by the NASA Kepler Mission. Neighboring stars are a potential source of false positive signals. These stars also blend into Kepler light curves, affecting estimated planet properties, and are important for an understanding of planets in multiple star systems. Deep images with high angular resolution help to validate candidate planets by excluding potential background eclipsing binaries as the source of the transit signals. A study of 18 Kepler Object of Interest stars hosting a total of 28 candidate and validated planets is presented. Validation levels are determined for 18 planets against the likelihood of a false positive from a background eclipsing binary. Most of these are validated at the 99% level or higher, including five newly validated planets in two systems: Kepler-430 and Kepler-431. The stellar properties of the candidate host stars are determined by supplementing existing literature values with new spectroscopic characterizations. Close neighbors of seven of these stars are examined using multi-wavelength photometry to determine their nature and influence on the candidate planet properties. Most of the close neighbors appear to be gravitationally bound secondaries, while a few are best explained as closely co-aligned field stars. Revised planet properties are derived for each candidate and validated planet, including cases where the close neighbors are the potential host stars.

  19. LAMOST OBSERVATIONS IN THE KEPLER FIELD. I. DATABASE OF LOW-RESOLUTION SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Cat, P. De; Ren, A. B.; Yang, X. H. [Royal observatory of Belgium, Ringlaan 3, B-1180 Brussel (Belgium); Fu, J. N. [Department of Astronomy, Beijing Normal University, 19 Avenue Xinjiekouwai, Beijing 100875 (China); Shi, J. R.; Luo, A. L.; Yang, M.; Wang, J. L.; Zhang, H. T.; Shi, H. M.; Zhang, W. [Key Lab for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Dong, Subo [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing, 100871 (China); Catanzaro, G.; Frasca, A. [INAF—Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Corbally, C. J. [Vatican Observatory Research Group, Steward Observatory, Tucson, AZ 85721-0065 (United States); Gray, R. O. [Department of Physics and Astronomy, Appalachian State University, Boone, NC 28608 (United States); Żakowicz, J. Molenda- [Astronomical Institute of the University of Wrocław, ul. Kopernika 11, 51-622 Wrocław (Poland); Uytterhoeven, K. [Instituto de Astrofísica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Briquet, M. [Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 19C, B-4000 Liège (Belgium); Bruntt, H., E-mail: Peter.DeCat@oma.be [Stellar Astrophysics Center, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); and others

    2015-09-15

    The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude pulsation modes that were undetectable from Earth. The long time base of Kepler light curves allows for the accurate determination of the frequencies and amplitudes of pulsation modes needed for in-depth asteroseismic modeling. However, for an asteroseismic study to be successful, the first estimates of stellar parameters need to be known and they cannot be derived from the Kepler photometry itself. The Kepler Input Catalog provides values for the effective temperature, surface gravity, and metallicity, but not always with sufficient accuracy. Moreover, information on the chemical composition and rotation rate is lacking. We are collecting low-resolution spectra for objects in the Kepler field of view with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (lamost, Xinglong observatory, China). All of the requested fields have now been observed at least once. In this paper, we describe those observations and provide a useful database for the whole astronomical community.

  20. ARCHITECTURE OF PLANETARY SYSTEMS BASED ON KEPLER DATA: NUMBER OF PLANETS AND COPLANARITY

    International Nuclear Information System (INIS)

    Fang, Julia; Margot, Jean-Luc

    2012-01-01

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1-6. We created models of planetary systems with different distributions of planet multiplicity and inclinations, simulated observations of these systems by Kepler, and compared the properties of the transits of detectable objects to actual Kepler planet detections. Specifically, we compared with both the Kepler sample's transit numbers and normalized transit duration ratios in order to determine each model's goodness of fit. We did not include any constraints from radial velocity surveys. Based on our best-fit models, 75%-80% of planetary systems have one or two planets with orbital periods less than 200 days. In addition, over 85% of planets have orbital inclinations less than 3° (relative to a common reference plane). This high degree of coplanarity is comparable to that seen in our solar system. These results have implications for planet formation and evolution theories. Low inclinations are consistent with planets forming in a protoplanetary disk, followed by evolution without significant and lasting perturbations from other bodies capable of increasing inclinations.

  1. Lifting Transit Signals from the Kepler Noise Floor. I. Discovery of a Warm Neptune

    Science.gov (United States)

    Kunimoto, Michelle; Matthews, Jaymie M.; Rowe, Jason F.; Hoffman, Kelsey

    2018-01-01

    Light curves from the 4-year Kepler exoplanet hunting mission have been searched for transits by NASA’s Kepler team and others, but there are still important discoveries to be made. We have searched the light curves of 400 Kepler Objects of Interest (KOIs) to find transit signals down to signal-to-noise ratio (S/N) ∼ 6, which is under the limit of S/N ∼ 7.1 that has been commonly adopted as a strict threshold to distinguish between a transit candidate and false alarm. We detect four new and convincing planet candidates ranging in radius from near-Mercury-size to slightly larger than Neptune. We highlight the discovery of KOI-408.05 (period = 637 days; radius = 4.9 R ⊕ incident flux = 0.6 S ⊕), a planet candidate within its host star’s Habitable Zone. We dub this planet a “warm Neptune,” a likely volatile-rich world that deserves closer inspection. KOI-408.05 joins 21 other confirmed and candidate planets in the current Kepler sample with semimajor axes a > 1.4 au. These discoveries are significant as a demonstration that the S/N threshold for detection used by the Kepler project is open to debate.

  2. A PSF photometry tool for NASA's Kepler, K2, and TESS missions

    Science.gov (United States)

    Cardoso, Jose Vinicius De Miranda; Barentsen, Geert; Hedges, Christina L.; Gully-Santiago, Michael A.; Cody, Ann Marie; Montet, Ben

    2018-01-01

    NASA's Kepler and K2 missions have impacted all areas of astrophysics in unique and important ways by delivering high-precision time series data on asteroids, stars, and galaxies. For example, both the official Kepler pipeline and the various community-owned pipelines have been successful at discovering a myriad of transiting exoplanets around a wide range of stellar types. However, the existing pipelines tend to focus on studying isolated stars using simple aperture photometry, and often perform sub-optimally in crowded fields where objects are blended. To address this issue, we present a Point Spread Function (PSF) photometry toolkit for Kepler and K2 which is able to extract light curves from crowded regions, such as the Beehive Cluster, the Lagoon Nebula, and the M67 globular cluster, which were all recently observed by Kepler. We present a detailed discussion on the theory, the practical use, and demonstrate our tool on various levels of crowding. Finally, we discuss the future use of the tool on data from the TESS mission. The code is open source and available on GitHub as part of the PyKE toolkit for Kepler/K2 data analysis.

  3. Role of mini-scleral gas-permeable lenses in the treatment of corneal disorders.

    Science.gov (United States)

    Ye, Ping; Sun, Amy; Weissman, Barry A

    2007-03-01

    Case report on the clinical implications of mini-scleral gas-permeable contact lenses in the treatment of corneal disorders. Three patients with different corneal disorders were fitted with Jupiter design mini-scleral gas-permeable contact lenses. All three patients achieved excellent vision and comfort. The contact lenses were tolerated well, and no complications were observed. Mini-scleral gas-permeable contact lenses provide a good option for patients who require gas-permeable contact lenses for optimal visual function but do not tolerate corneal contact lenses. Mini-scleral lenses are also an excellent therapeutic tool in the treatment of at least some forms of severe dry eyes.

  4. Limits on Surface Gravities of Kepler Planet-candidate Host Stars from Non-detection of Solar-like Oscillations

    NARCIS (Netherlands)

    Campante, T.L.; Chaplin, W.J.; Lund, M.N.; Huber, D.; Hekker, S.; García, R.A.; Corsaro, E.; Handberg, R.; Miglio, A.; Arentoft, T.; Basu, S.; Bedding, T.R.; Christensen-Dalsgaard, J.; Davies, G.R.; Elsworth, Y.P.; Gilliland, R.L.; Karoff, C.; Kawaler, S.D.; Kjeldsen, H.; Lundkvist, M.; Metcalfe, T.S.; Silva Aguirre, V.; Stello, D.

    2014-01-01

    We present a novel method for estimating lower-limit surface gravities (log g) of Kepler targets whose data do not allow the detection of solar-like oscillations. The method is tested using an ensemble of solar-type stars observed in the context of the Kepler Asteroseismic Science Consortium. We

  5. Red Clump stars in Kepler open cluster NGC 6819

    Directory of Open Access Journals (Sweden)

    Abedigamba O.P.

    2015-01-01

    Full Text Available We measure the large frequency separation, Δν, and the frequency of maximum amplitude, νmax, for 10 Red Clump (RC single member (SM stars in the Kepler open cluster NGC 6819. We derive luminosities and masses for each individual RC star. A comparison of the observations with an isochrone of Age = 2.5 Gyr, Z = 0.017 with no mass loss using a statistical techniques is made. A fractional mass loss of 5 ± 3 percent is obtained if we assume that no correction to Δν between RC and red-giant branch (RGB is necessary. However, models suggest that an effective correction of about 1.9 percent in Δν is required to obtain the correct mass of RC stars owing to the different internal structures of stars in the two evolutionary stages. In this case we find that the mass loss in the red giant branch is not significantly different from zero. This finding confirms that of [6]. It is clear that the mass estimate obtained by asteroseismology is not sufficient to deduce the mass loss on the red giant branch. However, it is clearly only a few percent at most.

  6. Solving Many Point Particle Interactions Using the Kepler Route

    Directory of Open Access Journals (Sweden)

    Al Rabeh R. H.

    2010-01-01

    Full Text Available Events in nature can be described using fields and their associated partial differential equations, or equivalently, the mechanics of interaction of point particles described by ordinary differential equations. The field approach can be looked at as the statistical average of the particle approach and in this sense is more economical for computing. The particle approach, on the other hand, is more fundamental but requires enormous computing power as the model has to follow the movements of every individual particle in the interaction. The present work aims at reducing such computing task by solving the problem of many particle interactions (under a central force environment in an analytical form for one pair of particlesusing a Kepler type formula- giving the position of the particle as a function of time only. The resulting (analytical formula is then used to write the result of the many-particle interaction using simple vector superposition. This approach takes less computing time and can give greater numerical stability when the distances between the particles become small and the force grows as the inverse square of the separation distance.

  7. Solving Many Point Particle Interactions Using the Kepler Route

    Directory of Open Access Journals (Sweden)

    Al Rabeh R. H.

    2010-01-01

    Full Text Available Events in nature can be described using fields and their associated partial differential equations, or equivalently, the mechanics of interaction of point particles described by ordinary differential equations. The field approach can be looked at as the statistical average of the particle approach and in this sense is more economical for computing. The particle approach, on the other hand, is more fundamental but requires enormous computing power as the model has to follow the movements of every individual particle in the interaction. The present work aims at reducing such computing task by solving the problem of many particle interactions (under a central force environment in an analytical form for one pair of particles using a Kepler type formula- giving the position of the particle as a function of time only. The resulting (analytical formula is then used to write the result of the many-particle interaction using simple vector superposition. This approach takes less computing time and can give greater numerical stability when the distances between the particles become small and the force grows as the inverse square of the separation distance.

  8. Milgrom's revision of cosmic dynamics: Amending Newton's laws or Keplers?

    Science.gov (United States)

    Felten, J. E.

    1983-01-01

    Milgrom's recent revision of Newtonian dynamics was introduced to eliminate the inference that large quantities of invisible mass exist in galaxies. Simple examples show that a Milgrom acceleration, in the form presented so far, imply other far-reaching changes in dynamics. The momentum of an isolated system is not conserved, and the usual theorem for center-of-mass motion of any system does not hold. Naive applications require extreme caution. The model fails to provide a complete description of particle dynamics and should be thought of as a revision of Kepler's laws rather than Newton's. The Milgrom acceleration also implies fundamental changes in cosmology. A quasi-Newtonian calculation adapted from Newtonian cosmology suggests that a Milgrom universe will recollapse even if the classical closure parameter theta is less than 1. The solution, however, fails to satisfy the cosmological principle. Reasons for the breakdown of this calculation are examined. A theory of gravitation needed before the behavior of a Milgrom universe can be predicted.

  9. SELECTION, PRIORITIZATION, AND CHARACTERISTICS OF KEPLER TARGET STARS

    International Nuclear Information System (INIS)

    Batalha, Natalie M.; Borucki, William J.; Koch, David G.; Bryson, Stephen T.; Haas, Michael R.; Brown, Timothy M.; Caldwell, Douglas A.; Hall, Jennifer R.; Gilliland, Ronald L.; Latham, David W.; Meibom, Soren; Monet, David G.

    2010-01-01

    The Kepler Mission began its 3.5 year photometric monitoring campaign in 2009 May on a select group of approximately 150,000 stars. The stars were chosen from the ∼ half million in the field of view that are brighter than 16th magnitude. The selection criteria are quantitative metrics designed to optimize the scientific yield of the mission with regard to the detection of Earth-size planets in the habitable zone. This yields more than 90,000 G-type stars on or close to the main sequence, >20, 000 of which are brighter than 14th magnitude. At the temperature extremes, the sample includes approximately 3000 M-type dwarfs and a small sample of O- and B-type MS stars (<200). The small numbers of giants are included in the sample: ∼5000 stars with surface gravities log(g) < 3.5. We present a brief summary of the selection process and the stellar populations it yields in terms of surface gravity, effective temperature, and apparent magnitude. In addition to the primary, statistically derived target set, several ancillary target lists were manually generated to enhance the science of the mission, examples being: known eclipsing binaries, open cluster members, and high proper motion stars.

  10. A Kepler Workflow Tool for Reproducible AMBER GPU Molecular Dynamics.

    Science.gov (United States)

    Purawat, Shweta; Ieong, Pek U; Malmstrom, Robert D; Chan, Garrett J; Yeung, Alan K; Walker, Ross C; Altintas, Ilkay; Amaro, Rommie E

    2017-06-20

    With the drive toward high throughput molecular dynamics (MD) simulations involving ever-greater numbers of simulation replicates run for longer, biologically relevant timescales (microseconds), the need for improved computational methods that facilitate fully automated MD workflows gains more importance. Here we report the development of an automated workflow tool to perform AMBER GPU MD simulations. Our workflow tool capitalizes on the capabilities of the Kepler platform to deliver a flexible, intuitive, and user-friendly environment and the AMBER GPU code for a robust and high-performance simulation engine. Additionally, the workflow tool reduces user input time by automating repetitive processes and facilitates access to GPU clusters, whose high-performance processing power makes simulations of large numerical scale possible. The presented workflow tool facilitates the management and deployment of large sets of MD simulations on heterogeneous computing resources. The workflow tool also performs systematic analysis on the simulation outputs and enhances simulation reproducibility, execution scalability, and MD method development including benchmarking and validation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  11. How far are extraterrestrial life and intelligence after Kepler?

    Science.gov (United States)

    Wandel, Amri

    2017-08-01

    The Kepler mission has shown that a significant fraction of all stars may have an Earth-size habitable planet. A dramatic support was the recent detection of Proxima Centauri b. Using a Drake-equation like formalism I derive an equation for the abundance of biotic planets as a function of the relatively modest uncertainty in the astronomical data and of the (yet unknown) probability for the evolution of biotic life, Fb. I suggest that Fb may be estimated by future spectral observations of exoplanet biomarkers. It follows that if Fb is not very small, then a biotic planet may be expected within about 10 light years from Earth. Extending this analyses to advanced life, I derive expressions for the distance to putative civilizations in terms of two additional Drake parameters - the probability for evolution of a civilization, Fc, and its average longevity. Assuming "optimistic" values for the Drake parameters, (Fb Fc 1), and a broadcasting duration of a few thousand years, the likely distance to the nearest civilizations detectable by SETI is of the order of a few thousand light years. Finally I calculate the distance and probability of detecting intelligent signals with present and future radio telescopes such as Arecibo and SKA and how it could constrain the Drake parameters.

  12. Two Earth-sized planets orbiting Kepler-20.

    Science.gov (United States)

    Fressin, Francois; Torres, Guillermo; Rowe, Jason F; Charbonneau, David; Rogers, Leslie A; Ballard, Sarah; Batalha, Natalie M; Borucki, William J; Bryson, Stephen T; Buchhave, Lars A; Ciardi, David R; Désert, Jean-Michel; Dressing, Courtney D; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Henze, Christopher E; Holman, Matthew J; Howard, Andrew; Howell, Steve B; Jenkins, Jon M; Koch, David G; Latham, David W; Lissauer, Jack J; Marcy, Geoffrey W; Quinn, Samuel N; Ragozzine, Darin; Sasselov, Dimitar D; Seager, Sara; Barclay, Thomas; Mullally, Fergal; Seader, Shawn E; Still, Martin; Twicken, Joseph D; Thompson, Susan E; Uddin, Kamal

    2011-12-20

    Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R(⊕)), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R(⊕)) and the other smaller than the Earth (0.87R(⊕)), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative hypothesis that the signals result from an eclipsing binary star. Theoretical considerations imply that these planets are rocky, with a composition of iron and silicate. The outer planet could have developed a thick water vapour atmosphere.

  13. Milgrom's revision of cosmic dynamics: Amending Newton's laws or Keplers

    International Nuclear Information System (INIS)

    Felten, J.E.

    1983-12-01

    Milgrom's recent revision of Newtonian dynamics was introduced to eliminate the inference that large quantities of invisible mass exist in galaxies. Simple examples show that a Milgrom acceleration, in the form presented so far, imply other far-reaching changes in dynamics. The momentum of an isolated system is not conserved, and the usual theorem for center-of-mass motion of any system does not hold. Naive applications require extreme caution. The model fails to provide a complete description of particle dynamics and should be thought of as a revision of Kepler's laws rather than Newton's. The Milgrom acceleration also implies fundamental changes in cosmology. A quasi-Newtonian calculation adapted from Newtonian cosmology suggests that a Milgrom universe will recollapse even if the classical closure parameter theta is less than 1. The solution, however, fails to satisfy the cosmological principle. Reasons for the breakdown of this calculation are examined. A theory of gravitation needed before the behavior of a Milgrom universe can be predicted

  14. TIDALLY INDUCED PULSATIONS IN KEPLER ECLIPSING BINARY KIC 3230227

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhao; Gies, Douglas R. [Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 5060, Atlanta, GA 30302-5060 (United States); Fuller, Jim, E-mail: guo@astro.gsu.edu, E-mail: gies@chara.gsu.edu, E-mail: jfuller@caltech.edu [TAPIR, Walter Burke Institute for Theoretical Physics, Mailcode 350-17, Caltech, Pasadena, CA 91125 (United States)

    2017-01-01

    KIC 3230227 is a short period (P  ≈ 7.0 days) eclipsing binary with a very eccentric orbit ( e  = 0.6). From combined analysis of radial velocities and Kepler light curves, this system is found to be composed of two A-type stars, with masses of M {sub 1} = 1.84 ± 0.18  M {sub ⊙}, M {sub 2} = 1.73 ± 0.17  M {sub ⊙} and radii of R {sub 1} = 2.01 ± 0.09  R {sub ⊙}, R {sub 2} = 1.68 ± 0.08 R {sub ⊙} for the primary and secondary, respectively. In addition to an eclipse, the binary light curve shows a brightening and dimming near periastron, making this a somewhat rare eclipsing heartbeat star system. After removing the binary light curve model, more than 10 pulsational frequencies are present in the Fourier spectrum of the residuals, and most of them are integer multiples of the orbital frequency. These pulsations are tidally driven, and both the amplitudes and phases are in agreement with predictions from linear tidal theory for l  = 2, m  = −2 prograde modes.

  15. Adjustable adaptive compact fluidic phoropter with no mechanical translation of lenses

    OpenAIRE

    Marks, Randall; Mathine, David L.; Peyman, Gholam; Schwiegerling, Jim; Peyghambarian, N.

    2010-01-01

    We demonstrate a compact optical phoroptor consisting of adjustable astigmatic and defocus lenses. The lenses are fluidically controlled and allow for an arbitrary refractive error to be corrected without mechanically moving lenses. Shack–Hartmann measurements were used to characterize the optical properties of the individual lenses. The lenses were then assembled into the phoropter and controlled with three separate fluid controls. The phoroptor was verified by correcting the vision of a mod...

  16. A flat inner disc model as an alternative to the Kepler dichotomy in the Q1-Q16 planet population

    Science.gov (United States)

    Bovaird, T.; Lineweaver, C. H.

    2017-06-01

    We use simulated planetary systems to model the planet multiplicity of Kepler stars. Previous studies have underproduced single planet systems and invoked the so-called Kepler dichotomy, where the planet forming ability of a Kepler star is dichotomous, producing either few or many transiting planets. In this paper, we show that the Kepler dichotomy is only required when the inner part of planetary discs are just assumed to be flared. When the inner part of planetary discs are flat, we reproduce the observed planet multiplicity of Kepler stars without the need to invoke a dichotomy. We find that independent of the disc model assumed, the mean number of planets per star μ ≈ 2 for orbital periods between 3 and 200 d, and for planetary radii between 1 and 5 Earth radii. This contrasts with the Solar system where no planets occupy the same parameter space.

  17. What To Know If Your Child Wants Contact Lenses

    Science.gov (United States)

    ... and wearing decorative lenses purchased from flea markets, beauty supply stores, the Internet and other sources. These ... State & Local Officials Consumers Health Professionals Science & Research Industry Scroll back to top Popular Content Home Latest ...

  18. Fluidic astigmatic and spherical lenses for ophthalmic applications

    Science.gov (United States)

    Marks, Randall Lee

    Fluidic lenses have been developed for ophthalmic applications. The lenses use a pressure differential to deform a membrane, which separates two fluids with different indexes of refraction. The change in membrane shape creates changes in the optical wavefront. By utilizing different boundary conditions on the membrane, the progression of the membrane shape can be controlled. Specifically, a circular restraint is used to produce optical power, whereas a rectangular restraint is used to produce a combination of power and astigmatism. These lenses are analyzed for dominant properties and wavefront quality. By combining 2 rectangular restraint lenses at 45° and a circular restraint lens, both orthogonal second order Zernike astigmatisms as well as second order power can be independently controlled. This combination can also be described as independent control of ophthalmic cylinder, cylinder axis, and power, which is required to create a basic phoropter. A fluidic phoropter is demonstrated and analyzed in this manuscript.

  19. Transparent nanostructured photochromic UV-blocking soft contact lenses.

    Science.gov (United States)

    Pek, Y Shona; Wu, Hong; Chow, Edwin Py; Ying, Jackie Y

    2016-06-01

    We aim to develop transparent UV-blocking photochromic soft contact lenses via polymerization of a bicontinuous nanoemulsion. Transparent nanostructured polymers were prepared by incorporating a polymerizable surfactant and thermal initiator together with water, monomers, UV blockers and photochromic dyes. The polymers were characterized using oxygen permeometer, tensile tester, electron microscope, UV spectrophotometer, corneal cell culture and testing in rabbits. The polymers have good oxygen permeability, water content, stiffness, strength and UV-blocking ability comparable to commercial UV-blocking soft contact lenses. Their response to UV light is comparable to photochromic spectacle lenses, particularly in reverse transition from colored to colorless state. They are nontoxic and nonleaching. Our photochromic UV-blocking contact lenses provide a novel alternative to photochromic spectacles.

  20. [Unusual complications after wearing hard and soft contact lenses].

    Science.gov (United States)

    Roth, H W; Teuchert, J

    1990-01-01

    In a clinical long-term study over a period of 10 years with 3850 patients wearing hard and soft contact lenses, unusual reactions of the cornea and perilimbal conjunctiva have been observed in 3% of all cases. Mainly corneal abrasions, cracks, clouds and mosaics have been observed, which were analyzed as being rare contact lens complications. The causes were lack of proper maintenance of the contact lenses, such as mistakes in cleaning and disinfecting the lenses, mishandling or toxic and allergic reactions due to cleaning and disinfection solutions. Only exact ophthalmological monitoring of the anterior parts of the eye and laboratory tests on the worn lenses permit differentiation between primary eye diseases and contact lens-induced complications.

  1. Adaptive silicone-membrane lenses: planar vs. shaped membrane

    CSIR Research Space (South Africa)

    Schneider, F

    2009-08-01

    Full Text Available In this paper the authors compare the performance and optical quality of two types of adaptive fluidic silicone-membrane lenses. The membranes feature either a homogeneous thickness, or it is shaped resulting in an inhomogeneous cross...

  2. Halloween Safety: Costumes, Candy, and Colored Contact Lenses

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Halloween Safety: Costumes, Candy, and Colored Contact Lenses Share ... can cause injuries that haunt you long after Halloween. Enjoy a safe and happy Halloween by following ...

  3. Gravitational lensing by a smoothly variable surface mass density

    Science.gov (United States)

    Paczynski, Bohdan; Wambsganss, Joachim

    1989-01-01

    The statistical properties of gravitational lensing due to smooth but nonuniform distributions of matter are considered. It is found that a majority of triple images had a parity characteristic for 'shear-induced' lensing. Almost all cases of triple or multiple imaging were associated with large surface density enhancements, and lensing objects were present between the images. Thus, the observed gravitational lens candidates for which no lensing object has been detected between the images are unlikely to be a result of asymmetric distribution of mass external to the image circle. In a model with smoothly variable surface mass density, moderately and highly amplified images tended to be single rather than multiple. An opposite trend was found in models which had singularities in the surface mass distribution.

  4. Lensing of 21-cm fluctuations by primordial gravitational waves.

    Science.gov (United States)

    Book, Laura; Kamionkowski, Marc; Schmidt, Fabian

    2012-05-25

    Weak-gravitational-lensing distortions to the intensity pattern of 21-cm radiation from the dark ages can be decomposed geometrically into curl and curl-free components. Lensing by primordial gravitational waves induces a curl component, while the contribution from lensing by density fluctuations is strongly suppressed. Angular fluctuations in the 21-cm background extend to very small angular scales, and measurements at different frequencies probe different shells in redshift space. There is thus a huge trove of information with which to reconstruct the curl component of the lensing field, allowing tensor-to-scalar ratios conceivably as small as r~10(-9)-far smaller than those currently accessible-to be probed.

  5. The Danger of Using Tap Water with Contact Lenses

    Science.gov (United States)

    Acanthamoeba is a microbe that is very common in tap water. It has two forms: the trophozoite and the cyst. These trophozoites and cysts can stick to the surface of your contact lenses and then infect your eye.

  6. Clinical Study of Focus NIGHT &DAY® contact lenses | Aldebasi ...

    African Journals Online (AJOL)

    wear contact lenses for up to 3 weeks without ocular complications. Visual acuity, tear functions or corneal structure are not altered. Keywords: optometry, silicone hydrogel materials, resolution, ocular. Sudan Journal of Medical Sciences Vol.

  7. Exploring cosmic origins with CORE: Gravitational lensing of the CMB

    Science.gov (United States)

    Challinor, A.; Allison, R.; Carron, J.; Errard, J.; Feeney, S.; Kitching, T.; Lesgourgues, J.; Lewis, A.; Zubeldía, Í.; Achucarro, A.; Ade, P.; Ashdown, M.; Ballardini, M.; Banday, A. J.; Banerji, R.; Bartlett, J.; Bartolo, N.; Basak, S.; Baumann, D.; Bersanelli, M.; Bonaldi, A.; Bonato, M.; Borrill, J.; Bouchet, F.; Boulanger, F.; Brinckmann, T.; Bucher, M.; Burigana, C.; Buzzelli, A.; Cai, Z.-Y.; Calvo, M.; Carvalho, C.-S.; Castellano, G.; Chluba, J.; Clesse, S.; Colantoni, I.; Coppolecchia, A.; Crook, M.; d'Alessandro, G.; de Bernardis, P.; de Gasperis, G.; De Zotti, G.; Delabrouille, J.; Di Valentino, E.; Diego, J.-M.; Fernandez-Cobos, R.; Ferraro, S.; Finelli, F.; Forastieri, F.; Galli, S.; Genova-Santos, R.; Gerbino, M.; González-Nuevo, J.; Grandis, S.; Greenslade, J.; Hagstotz, S.; Hanany, S.; Handley, W.; Hernandez-Monteagudo, C.; Hervías-Caimapo, C.; Hills, M.; Hivon, E.; Kiiveri, K.; Kisner, T.; Kunz, M.; Kurki-Suonio, H.; Lamagna, L.; Lasenby, A.; Lattanzi, M.; Liguori, M.; Lindholm, V.; López-Caniego, M.; Luzzi, G.; Maffei, B.; Martinez-González, E.; Martins, C. J. A. P.; Masi, S.; Matarrese, S.; McCarthy, D.; Melchiorri, A.; Melin, J.-B.; Molinari, D.; Monfardini, A.; Natoli, P.; Negrello, M.; Notari, A.; Paiella, A.; Paoletti, D.; Patanchon, G.; Piat, M.; Pisano, G.; Polastri, L.; Polenta, G.; Pollo, A.; Poulin, V.; Quartin, M.; Remazeilles, M.; Roman, M.; Rubino-Martin, J.-A.; Salvati, L.; Tartari, A.; Tomasi, M.; Tramonte, D.; Trappe, N.; Trombetti, T.; Tucker, C.; Valiviita, J.; Van de Weijgaert, R.; van Tent, B.; Vennin, V.; Vielva, P.; Vittorio, N.; Young, K.; Zannoni, M.

    2018-04-01

    Lensing of the cosmic microwave background (CMB) is now a well-developed probe of the clustering of the large-scale mass distribution over a broad range of redshifts. By exploiting the non-Gaussian imprints of lensing in the polarization of the CMB, the CORE mission will allow production of a clean map of the lensing deflections over nearly the full-sky. The number of high-S/N modes in this map will exceed current CMB lensing maps by a factor of 40, and the measurement will be sample-variance limited on all scales where linear theory is valid. Here, we summarise this mission product and discuss the science that will follow from its power spectrum and the cross-correlation with other clustering data. For example, the summed mass of neutrinos will be determined to an accuracy of 17 meV combining CORE lensing and CMB two-point information with contemporaneous measurements of the baryon acoustic oscillation feature in the clustering of galaxies, three times smaller than the minimum total mass allowed by neutrino oscillation measurements. Lensing has applications across many other science goals of CORE, including the search for B-mode polarization from primordial gravitational waves. Here, lens-induced B-modes will dominate over instrument noise, limiting constraints on the power spectrum amplitude of primordial gravitational waves. With lensing reconstructed by CORE, one can "delens" the observed polarization internally, reducing the lensing B-mode power by 60 %. This can be improved to 70 % by combining lensing and measurements of the cosmic infrared background from CORE, leading to an improvement of a factor of 2.5 in the error on the amplitude of primordial gravitational waves compared to no delensing (in the null hypothesis of no primordial B-modes). Lensing measurements from CORE will allow calibration of the halo masses of the tens of thousands of galaxy clusters that it will find, with constraints dominated by the clean polarization-based estimators. The 19

  8. Amplitude Variability in gamma Dor and delta Sct Stars Observed by Kepler

    Energy Technology Data Exchange (ETDEWEB)

    Guzik, Joyce Ann [Los Alamos National Laboratory; Kosak, Mary Katherine [Los Alamos National Laboratory; Bradley, Paul Andrew [Los Alamos National Laboratory; Jackiewicz, Jason [New Mexico State University, Las Cruces, NM

    2015-08-17

    The NASA Kepler spacecraft data revealed a large number of new multimode nonradially pulsating gamma Dor and delta Sct variable stars. The Kepler high-precision long time-series photometry makes it possible to study amplitude variations of the frequencies, and recent literature on amplitude and frequency variations in nonradially pulsating variables is summarized. Several methods are applied to study amplitude variability in about a dozen gamma Doradus or delta Scuti candidate variable stars observed for several quarters as part of the Kepler Guest Observer program. The magnitude and timescale of the amplitude variations are discussed, along with the presence or absence of correlations between amplitude variations for different frequencies of a given star. Proposed causes of amplitude spectrum variability that will require further investigation are also discussed.

  9. Kepler-223: A Resonant Chain of Four Sub-Neptune Planets

    Science.gov (United States)

    Mills, Sean M.; Clark Fabrycky, Daniel; Migaszewski, Cezary; Ford, Eric B.; Petigura, Erik; Isaacson, Howard T.

    2015-12-01

    The Kepler mission has revealed an abundance of pairs of planets in the same system which often lie near, but not exactly on, resonance. Understanding how and when they entered a resonance and were removed from it has implications for their birthplaces and planetary structure. Here we characterize Kepler-223 (KOI-730), an outstanding example of a system of small planets in resonance. We perform TTV, photodynamic, stability, and migration analyses to determine the system's most likely current parameters and resonant state. Its four sub-Neptune planets form a chain linked by 4:3, 3:2, and 2:1 resonances that cause measurable dynamical effects and imply a disk-migration origin. Tidal dissipation in the planets or wide-scale instability may eventually transform resonant chains of planets like Kepler-223 into the more common type of architecture.

  10. LAMOST OBSERVATIONS IN THE KEPLER FIELD: SPECTRAL CLASSIFICATION WITH THE MKCLASS CODE

    Energy Technology Data Exchange (ETDEWEB)

    Gray, R. O. [Department of Physics and Astronomy, Appalachian State University, Boone, NC 28608 (United States); Corbally, C. J. [Vatican Observatory Research Group, Steward Observatory, Tucson, AZ 85721-0065 (United States); Cat, P. De [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel (Belgium); Fu, J. N.; Ren, A. B. [Department of Astronomy, Beijing Normal University, 19 Avenue Xinjiekouwai, Beijing 100875 (China); Shi, J. R.; Luo, A. L.; Zhang, H. T.; Wu, Y.; Cao, Z.; Li, G. [Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Zhang, Y.; Hou, Y.; Wang, Y. [Nanjing Institute of Astronomical Optics and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Nanjing 210042 (China)

    2016-01-15

    The LAMOST-Kepler project was designed to obtain high-quality, low-resolution spectra of many of the stars in the Kepler field with the Large Sky Area Multi Object Fiber Spectroscopic Telescope (LAMOST) spectroscopic telescope. To date 101,086 spectra of 80,447 objects over the entire Kepler field have been acquired. Physical parameters, radial velocities, and rotational velocities of these stars will be reported in other papers. In this paper we present MK spectral classifications for these spectra determined with the automatic classification code MKCLASS. We discuss the quality and reliability of the spectral types and present histograms showing the frequency of the spectral types in the main table organized according to luminosity class. Finally, as examples of the use of this spectral database, we compute the proportion of A-type stars that are Am stars, and identify 32 new barium dwarf candidates.

  11. Motions of Kepler circumbinary planets in restricted three-body problem under radiating primaries

    Energy Technology Data Exchange (ETDEWEB)

    Dermawan, B., E-mail: budider@as.itb.ac.id; Hidayat, T., E-mail: taufiq@as.itb.ac.id [Astronomy Research Division, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132 (Indonesia); Huda, I. N., E-mail: ibnu.nurul@students.itb.ac.id; Mandey, D., E-mail: mandey.de@gmail.com; Utama, J. A., E-mail: judhistira@yahoo.com; Tampubolon, I., E-mail: ihsan.tampubolon@gmail.com [Department of Astronomy, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132 (Indonesia); Wibowo, R. W., E-mail: ridlo.w.wibowo@gmail.com [Department of Computational Science, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jalan Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    By observing continuously a single field of view in the sky, Kepler mission reveals outstanding results on discoveries of exoplanets. One of its recent progress is the discoveries of circumbinary planets. A circumbinary planet is an exoplanet that moves around a binary system. In this study we investigate motions of Kepler circumbinary planets belong to six binary systems, namely Kepler-16, -34, -35, -38, -47, and -413. The motions are considered to follow the Restricted Three-Body Problem (RTBP). Because the primaries (central massive objects) are stars, they are both radiatives, while the planet is an infinitesimal object. The primaries move in nearly circular and elliptic orbits with respect to their center of masses. We describe, in general, motions of the circumbinary planets in RTBP under radiating primaries. With respect to the averaged zero velocity curves, we show that motions of the exoplanets are stable, in accordance with their Hill stabilities.

  12. On the connections between the classical and quantum-mechanical Kepler problems

    International Nuclear Information System (INIS)

    Dahl, J.P.; Jorgensen, T.G.

    1993-01-01

    The Runge-Lenz vector, which accounts for the accidental degeneracy of the non-relativistic Kepler problem, has been the subject matter of many studies, both in quantum mechanics and in classical mechanics. Much less attention has been paid to the Johnson-Lippmann operator which accounts for the accidental degeneracy of the relativistic Kepler problem in Dirac's quantum-mechanical description. In the present communication we discuss the properties of the Johnson-Lippmann operator. We show its relation to the non-relativistic Runge-Lenz vector and draw a connection to Sommerfield's early discussion of the relativistic Kepler problem. This enables us, inter alia, to give an explanation of the apparent coincidence of the energy expressions of the two theories

  13. Observations of Hot-Jupiter occultations combining Spitzer and Kepler photometry

    Directory of Open Access Journals (Sweden)

    Knutson H.

    2011-02-01

    Full Text Available We present the status of an ongoing program which aim at measuring occultations by their parent stars of transiting hot giant exoplanets discovered recently by Kepler. The observations are obtained in the near infrared with WarmSpitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of measuring the mid-occultation times and the relative occultation depths in each band-passes. Our measurements of occultations depths in the Kepler bandpass is turned into the determination of the optical geometric albedo Ag in this wavelength domain. The brightness temperatures of these planets are deduced from the infrared observations. We combine the optical and near infrared planetary emergent fluxes to obtain broad band emergent spectra of individual planet. We finally compare these spectra to hot Jupiter atmospheric models in order broadly distinguishing these atmospheres between different classes of models.

  14. 3D spin-orbit angle of Kepler-25 and HAT-P-7

    Directory of Open Access Journals (Sweden)

    Benomar Othman

    2015-01-01

    Full Text Available The number of discovered exoplanets now exceeds 1500, mostly due to the Kepler space instrument observations. Many of these planet orbit in less than a week around their host stars. This implies that the inward migration of those planets is a basic ingredient of successful theories of planet formation and evolution. Several mechanisms have been proposed to explain the observed periods, which lead to different orbit eccentricity and obliquity distributions. Here we summarise and discuss the results of obliquities for two Kepler stars: HAT-P-7 and Kepler-25. These are interesting stellar systems as we could carry out a joint analysis using asteroseismology, transit lightcurve and the Rossiter-McLaughlin effect in order to measure the three dimensional obliquity.

  15. Flare Rate and Statistics for the M Dwarf GJ 1243 With Kepler

    Science.gov (United States)

    Johnson, Emily; Davenport, James R. A.; Hawley, Suzanne L.

    2015-01-01

    Light curve data taken from the Kepler space telescope have been used to detect stellar flares. These data are a valuable resource for the study of flare rates and morphology, but currently flare samples must be validated by hand. FBEye (Flares By Eye) is an interactive program created to detect and manually validate these flares, with the goal of removing the need for human input. As a first year undergraduate student, I participated in this project by analyzing Kepler light curves and vetting stellar flares. Using 11 months of one-minute cadence data from GJ 1243, an M dwarf star, we classified each flare by energy and morphology. This work has been used to refine the FBEye program, which will eventually be applied to the entire catalogue of Kepler data. It is also part of a research paper on GJ 1243, which is currently in the publication process.

  16. What is Gravitational Lensing? (LBNL Summer Lecture Series)

    Energy Technology Data Exchange (ETDEWEB)

    Leauthaud, Alexie; Nakajima, Reiko [Berkeley Center for Cosmological Physics

    2009-07-28

    Summer Lecture Series 2009: Gravitational lensing is explained by Einstein's general theory of relativity: galaxies and clusters of galaxies, which are very massive objects, act on spacetime by causing it to become curved. Alexie Leauthaud and Reiko Nakajima, astrophysicists with the Berkeley Center for Cosmological Physics, will discuss how scientists use gravitational lensing to investigate the nature of dark energy and dark matter in the universe.

  17. Bilateral spontaneous subluxation of scleral-fixated intraocular lenses.

    Science.gov (United States)

    Assia, Ehud I; Nemet, Arie; Sachs, Dani

    2002-12-01

    Two young men with primary ectopic lenses had intracapsular cataract extraction and scleral fixation of posterior chamber intraocular lenses (PC IOLs) using 10-0 polypropylene sutures tied to the IOL eyelets. Three to 9 years after implantation, spontaneous IOL vertical subluxation occurred in all 4 eyes (5 IOL loops), probably because of suture breakage. Late subluxation of a sutured IOL may occur several years after implantation. Double fixation and thicker sutures should be considered, especially in young patients.

  18. Periodic self-lensing from accreting massive black hole binaries

    Science.gov (United States)

    D'Orazio, Daniel J.; Di Stefano, Rosanne

    2018-03-01

    Nearly 150 massive black hole binary (MBHB) candidates at sub-pc orbital separations have been reported in recent literature. Nevertheless, the definitive detection of even a single such object remains elusive. If at least one of the black holes is accreting, the light emitted from its accretion disc will be lensed by the other black hole for binary orbital inclinations near to the line of sight. This binary self-lensing could provide a unique signature of compact MBHB systems. We show that, for MBHBs with masses in the range 106-1010 M⊙ and with orbital periods less than ˜10 yr, strong lensing events should occur in one to 10s of per cent of MBHB systems that are monitored for an entire orbit. Lensing events will last from days for the less massive, shorter period MBHBs to a year for the most massive ˜10 year orbital period MBHBs. At small inclinations of the binary orbit to the line of sight, lensing must occur and will be accompanied by periodicity due to the relativistic Doppler boost. Flares at the same phase as the otherwise average flux of the Doppler modulation would be a smoking gun signature of self-lensing and can be used to constrain binary parameters. For MBHBs with separation ≳100 Schwarzschild radii, we show that finite-sized source effects could serve as a probe of MBH accretion disc structure. Finally, we stress that our lensing probability estimate implies that ˜10 of the known MBHB candidates identified through quasar periodicity should exhibit strong lensing flares.

  19. Optical and visual performance of aspheric soft contact lenses.

    Science.gov (United States)

    Efron, Suzanne; Efron, Nathan; Morgan, Philip B

    2008-03-01

    This study was conducted to investigate whether aspheric design soft contact lenses reduce ocular aberrations and result in better visual acuity and subjective appreciation of clinical performance compared with spherical soft contact lenses. A unilateral, double-masked, randomized and controlled study was undertaken in which ocular aberrations and high and low contrast logMAR visual acuity were measured on myopic subjects who wore aspheric design (Biomedics 55 Evolution, CooperVision) and spherical design (Biomedics 55, CooperVision) soft contact lenses. Ten subjects who had about -2.00 D myopia wore -2.00 D lenses and 10 subjects who had about -5.00 D myopia wore -5.00 D lenses. Measurements were made under photopic and mesopic lighting conditions. Subjects were invited to grade comfort, vision in photopic and mesopic conditions, and overall impression with the two lens types on 100 unit visual analogue scales. There was no significant difference in high contrast or low contrast visual acuity between the two lens designs of either power under photopic or mesopic conditions. Both lens designs displayed lower levels of spherical aberration compared with the "no lens" condition under photopic and mesopic light levels (p designs. There were no statistically significant differences in subjective appreciation of clinical performance between lens designs or lens powers. At least with respect to the brand of lenses tested, the fitting of aspheric design soft contact lenses does not result in superior visual acuity, aberration control, or subjective appreciation compared with equivalent spherical design soft contact lenses.

  20. High HIV Prevalence among Asylum Seekers Who Gave Birth in the Netherlands: A Nationwide Study Based on Antenatal HIV Tests.

    Science.gov (United States)

    Goosen, Simone; Hoebe, Christian J P A; Waldhober, Quita; Kunst, Anton E

    2015-01-01

    Asylum seekers are considered to be a particularly vulnerable group with respect to HIV. Data on the HIV prevalence among asylum seekers, however, are scarce. The aim of this study is to map the HIV prevalence among asylum seekers who gave birth in The Netherlands. We used a nationwide electronic medical records database from the community health services for asylum seekers (MOA). The study population consisted of 4,854 women and girls who delivered in asylum reception between 2000 and 2008. A unique electronic health data base was used and case allocation was based on ICPC-codes. The number of women and girls that was HIV positive during their last pregnancy was 80, of which 79 originated from sub-Saharan Africa. The prevalence for women from this region of origin (3.4%) was high compared to women from all other regions of origin (0.04%; OR = 90.2; 95%CI 12.5-648.8). The highest HIV prevalence rates were found for women from Rwanda (17.0%) and Cameroon (13.2%). HIV prevalence rates were higher among women who arrived in reception without partner (OR = 1.82; 95%CI 0.75-4.44) and unaccompanied minors (OR = 2.59; 95%CI 0.79-8.49), compared to women who arrived in reception with partner. We conclude that, among asylum-seeking women from sub-Saharan Africa giving birth in The Netherlands, the HIV prevalence is high compared to the host population. For women from other regions of origin, the prevalence is at the same level as in the host population. The high HIV prevalence underlines the importance of preventive interventions and voluntary HIV testing for sub-Saharan African asylum seekers as from shortly after arrival.

  1. Completing Kepler's Mission to Determine the Frequency of Earth-like Planets

    Science.gov (United States)

    Burke, Christopher

    2017-08-01

    The primary goal of NASA's Kepler mission is to estimate the frequency of Earth-sized planets orbiting in the habitable zone (HZ) of Sun-like stars (so called eta-Earth). Analysis of four years of Kepler data reveals an unprecedented population of more than 4400 planet candidates orbiting 3400 stars, however only a small subset of these ( 13 planets) fall into the regime of near-Earth-sized and in the HZ of a solar-type star. By accounting properly for detection biases that limit the catalog completeness and reliability we can turn an observed population into an intrinsic population and achieve Kepler's prime mission goal. Our team have shown that uncertainties in HZ occurrence rates for solar-type stars for all analyses to date are dominated by systematic uncertainties. The robustness of the 13 high-value Earth-like planet candidates is questionable due to their long periods and small transit depths - the Kepler team estimate that perhaps 50% of these are real planets. The proposed HST observations provide a pilot study to measure the photometric time series of the high-value, temperate terrestrial planet candidate Kepler-62f in order to confirm that it is not a false alarm. Long-duration high-precision observations from HST of this kind have not been attempted before and therefore we opt to waive the proprietary period of data collected during this pilot study. Successful confirmation will pave the way for a future large program to examine all of the Kepler G dwarf habitable Earth-sized planets and drastically improve the accuracy of eta-Earth estimates.

  2. Increasing the Sensitivity of the Kepler Legacy Archive to Habitable Zone Planets and Earth Analogs

    Science.gov (United States)

    Still, M.

    2014-04-01

    All legacy light curves archived by the Kepler project are available to the community. They are based upon simple aperture extractions from time-tagged pixel data. We demonstrate that this photometry method works well for the bright end of the Kepler target sample yet there is enormous scope for further gains in sensitivity to planet transits of faint stars in the sample. To this end, all pixel data have been made available in the archive. Methods for the user community to optimize aperture photometry and exploit point spread function modeling are being developed. Exploiting existing Kepler planet candidates, we showcase the signal-to-noise to be gained by these methods. We argue that at the faintest end of the candidate distribution, optimization provides a factor two improvement in sensitivity to transits, reaching beyond the signal-to-noise promised by the eight year mission, curtailed by reaction wheel failure after four years. These methods can provide potentially significant improvement to a number of facets of the Kepler mission: 1. Sensitivity to new planet candidates residing currently below the signal-to-noise detection threshold; 2. Characterizing known transit profiles to higher precision; 3. Identifying contamination from nearby sources and removing contamination bias from transit depths; 4. Mitigating focus and pointing systematics within the Kepler data, and 5. Allowing the direct characterization of time-dependent physical and detector biases within the image background. With exisiting focal plane calibrations, the number of targets that currently benefit from optimized photometry is relatively small, limited to sources of magnitude Kp > 16. However, with additional refinement of the focal plane calibration, improvement in light curve quality for objects 14 < Kp < 16 can be anticipated, impacting 50% of the Kepler target sample. These methods are equally applicable to data from the upcoming TESS mission and are potentially a critical component to

  3. Kepler Data Validation I: Architecture, Diagnostic Tests, and Data Products for Vetting Transiting Planet Candidates

    Science.gov (United States)

    Twicken, Joseph D.; Catanzarite, Joseph H.; Clarke, Bruce D.; Giroud, Forrest; Jenkins, Jon M.; Klaus, Todd C.; Li, Jie; McCauliff, Sean D.; Seader, Shawn E.; Tennenbaum, Peter; hide

    2018-01-01

    The Kepler Mission was designed to identify and characterize transiting planets in the Kepler Field of View and to determine their occurrence rates. Emphasis was placed on identification of Earth-size planets orbiting in the Habitable Zone of their host stars. Science data were acquired for a period of four years. Long-cadence data with 29.4 min sampling were obtained for approx. 200,000 individual stellar targets in at least one observing quarter in the primary Kepler Mission. Light curves for target stars are extracted in the Kepler Science Data Processing Pipeline, and are searched for transiting planet signatures. A Threshold Crossing Event is generated in the transit search for targets where the transit detection threshold is exceeded and transit consistency checks are satisfied. These targets are subjected to further scrutiny in the Data Validation (DV) component of the Pipeline. Transiting planet candidates are characterized in DV, and light curves are searched for additional planets after transit signatures are modeled and removed. A suite of diagnostic tests is performed on all candidates to aid in discrimination between genuine transiting planets and instrumental or astrophysical false positives. Data products are generated per target and planet candidate to document and display transiting planet model fit and diagnostic test results. These products are exported to the Exoplanet Archive at the NASA Exoplanet Science Institute, and are available to the community. We describe the DV architecture and diagnostic tests, and provide a brief overview of the data products. Transiting planet modeling and the search for multiple planets on individual targets are described in a companion paper. The final revision of the Kepler Pipeline code base is available to the general public through GitHub. The Kepler Pipeline has also been modified to support the Transiting Exoplanet Survey Satellite (TESS) Mission which is expected to commence in 2018.

  4. Lensing bias to CMB polarization measurements of compensated isocurvature perturbations

    Science.gov (United States)

    Heinrich, Chen

    2018-01-01

    Compensated isocurvature perturbations (CIPs) are opposite spatial fluctuations in the baryon and dark matter (DM) densities. They arise in the curvaton model and some models of baryogenesis. While the gravitational effects of baryon fluctuations are compensated by those of DM, leaving no observable impacts on the cosmic microwave background (CMB) at first order, they modulate the sound horizon at recombination, thereby correlating CMB anisotropies at different multipoles. As a result, CIPs can be reconstructed using quadratic estimators similarly to CMB detection of gravitational lensing. Because of these similarities, however, the CIP estimators are biased with lensing contributions that must be subtracted. These lensing contributions for CMB polarization measurement of CIPs are found to roughly triple the noise power of the total CIP estimator on large scales. In addition, the cross power with temperature and E -mode polarization are contaminated by lensing-ISW (integrated Sachs-Wolfe) correlations and reionization-lensing correlations respectively. For a cosmic-variance-limited temperature and polarization experiment measuring out to multipoles lmax=2500 , the lensing noise raises the detection threshold by a factor of 1.5, leaving a 2.7 σ detection possible for the maximal CIP signal in the curvaton model.

  5. Cosmological constraints from weak lensing non-Gaussian statistics

    Science.gov (United States)

    Liu, Jia; Haiman, Zoltan; Petri, Andrea; Hill, James; Hui, Lam; Kratochvil, Jan Michael; May, Morgan

    2016-01-01

    Weak gravitational lensing is one of the most promising techniques to probe dark energy. Our work to date suggests that the information in the nonlinear regime exceeds that in the two-point functions. Using the publicly available data from the 154 deg^2 CFHTLenS survey and a large suite of ray-tracing N-body simulations on a grid of 91 cosmological models, we find that constraints from peak counts are comparable to those from the power spectrum, and somewhat tighter when different smoothing scales are combined.I will also introduce the utility of cross-correlating weak galaxy lensing maps with CMB lensing maps, a technique that will be useful to probe structures at an intermediate redshift of 0.9, as larger weak lensing surveys such as HSC, DES, KiDS, Euclid, and LSST come online. We cross-correlate the CFHTLenS galaxy lensing convergence maps with Planck CMB lensing maps. Our results show two sigma tension with the constraints obtained from the Planck temperature measurements. I will discuss possible sources of the tension, including intrinsic alignments, photo-z uncertainties, masking of tSZ in the CMB maps, and the multiplicative bias.

  6. Invited Review Article: Development of crystal lenses for energetic photons

    International Nuclear Information System (INIS)

    Smither, Robert K.

    2014-01-01

    This paper follows the development of crystal diffraction lenses designed to focus energetic photons. It begins with the search for a solution to the astrophysics problem of how to detect weak astrophysics sources of gamma rays and x-rays. This led to the basic designs for a lens and to the understanding of basic limitations of lens design. The discussion of the development of crystal diffraction lenses is divided into two parts: lenses using crystals with mosaic structure, and lenses that use crystals with curved crystal planes. This second group divides into two sub-groups: (1) Curved crystals that are used to increase the acceptance angle of the diffraction of a monochromatic beam and to increase the energy bandwidth of the diffraction. (2) Curved crystals used to focus gamma ray beams. The paper describes how these two types of crystals affect the design of the corresponding crystal lenses in different fields: astrophysics, medical imaging, detection of weak, distant, gamma-ray sources, etc. The designs of crystal lenses for these applications are given in enough detail to allow the reader to design a lens for his own application

  7. Scleral contact lenses for the management of complicated ptosis.

    Science.gov (United States)

    Katsoulos, Konstantinos; Rallatos, Gerasimos Livir; Mavrikakis, Ioannis

    2017-10-20

    To present the management of three patients suffering from ptosis of various etiologies, with scleral contact lenses. Three patients (five eyes) with ptosis resulting from levator dehiscence due to long-term rigid gas permeable contact lens wear for keratoconus, phthisis bulbi, and myopathy due to Kearns-Sayre syndrome were identified during a 2-year period. They were fitted with scleral contact lenses in order to provide cosmesis by lifting the upper eyelid with the bulk of the lens, and simultaneously provide vision correction where applicable. The scleral contact lenses provided comfortable wear, significantly improved cosmesis as both palpebral aperture and marginal reflex distance were increased, and visual acuity was also subjectively and objectively improved. Two of the patients opted for the scleral contact lenses, whereas the parents of the third patient, a 10-year-old girl with Kearns-Sayre syndrome, chose to undergo ptosis surgery due to handling issues of the scleral contact lenses. Scleral contact lenses can be a useful addition to the treatment option for patients with complicated ptosis.

  8. Chromatic confocal microscope using hybrid aspheric diffractive lenses

    Science.gov (United States)

    Rayer, Mathieu; Mansfield, Daniel

    2014-05-01

    A chromatic confocal microscope is a single point non-contact distance measurement sensor. For three decades the vast majority of the chromatic confocal microscope use refractive-based lenses to code the measurement axis chromatically. However, such an approach is limiting the range of applications. In this paper the performance of refractive, diffractive and Hybrid aspheric diffractive are compared. Hybrid aspheric diffractive lenses combine the low geometric aberration of a diffractive lens with the high optical power of an aspheric lens. Hybrid aspheric diffractive lenses can reduce the number of elements in an imaging system significantly or create large hyper- chromatic lenses for sensing applications. In addition, diffractive lenses can improve the resolution and the dynamic range of a chromatic confocal microscope. However, to be suitable for commercial applications, the diffractive optical power must be significant. Therefore, manufacturing such lenses is a challenge. We show in this paper how a theoretical manufacturing model can demonstrate that the hybrid aspheric diffractive configuration with the best performances is achieved by step diffractive surface. The high optical quality of step diffractive surface is then demonstrated experimentally. Publisher's Note: This paper, originally published on 5/10/14, was replaced with a corrected/revised version on 5/19/14. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  9. The epidemiology of microbial keratitis with silicone hydrogel contact lenses.

    Science.gov (United States)

    Stapleton, Fiona; Keay, Lisa; Edwards, Katie; Holden, Brien

    2013-01-01

    It was widely anticipated that after the introduction of silicone hydrogel lenses, the risk of microbial keratitis would be lower than with hydrogel lenses because of the reduction in hypoxic effects on the corneal epithelium. Large-scale epidemiological studies have confirmed that the absolute and relative risk of microbial keratitis is unchanged with overnight use of silicone hydrogel materials. The key findings include the following: (1) The risk of infection with 30 nights of silicone hydrogel use is equivalent to 6 nights of hydrogel extended wear; (2) Occasional overnight lens use is associated with a greater risk than daily lens use; (3) The rate of vision loss due to corneal infection with silicone hydrogel contact lenses is similar to that seen in hydrogel lenses; (4) The spectrum of causative organisms is similar to that seen in hydrogel lenses, and the material type does not impact the corneal location of presumed microbial keratitis; and (5) Modifiable risk factors for infection include overnight lens use, the degree of exposure, failing to wash hands before lens handling, and storage case hygiene practice. The lack of change in the absolute risk of disease would suggest that exposure to large number of pathogenic organisms can overcome any advantages obtained from eliminating the hypoxic effects of contact lenses. Epidemiological studies remain important in the assessment of new materials and modalities. Consideration of an early adopter effect with studies involving new materials and modalities and further investigation of the impact of second-generation silicone hydrogel materials is warranted.

  10. Kepler Planet Detection Metrics: Automatic Detection of Background Objects Using the Centroid Robovetter

    Science.gov (United States)

    Mullally, Fergal

    2017-01-01

    We present an automated method of identifying background eclipsing binaries masquerading as planet candidates in the Kepler planet candidate catalogs. We codify the manual vetting process for Kepler Objects of Interest (KOIs) described in Bryson et al. (2013) with a series of measurements and tests that can be performed algorithmically. We compare our automated results with a sample of manually vetted KOIs from the catalog of Burke et al. (2014) and find excellent agreement. We test the performance on a set of simulated transits and find our algorithm correctly identifies simulated false positives approximately 50 of the time, and correctly identifies 99 of simulated planet candidates.

  11. KEPLER-10 c: A 2.2 EARTH RADIUS TRANSITING PLANET IN A MULTIPLE SYSTEM

    International Nuclear Information System (INIS)

    Fressin, Francois; Torres, Guillermo; Desert, Jean-Michel; Charbonneau, David; Holman, Matthew J.; Batalha, Natalie M.; Fortney, Jonathan J.; Fabrycky, Daniel C.; Rowe, Jason F.; Allen, Christopher; Borucki, William J.; Bryson, Stephen T.; Henze, Christopher E.; Brown, Timothy M.; Ciardi, David R.; Cochran, William D.; Deming, Drake; Dunham, Edward W.; Gautier III, Thomas N.; Gilliland, Ronald L.

    2011-01-01

    The Kepler mission has recently announced the discovery of Kepler-10 b, the smallest exoplanet discovered to date and the first rocky planet found by the spacecraft. A second, 45 day period transit-like signal present in the photometry from the first eight months of data could not be confirmed as being caused by a planet at the time of that announcement. Here we apply the light curve modeling technique known as BLENDER to explore the possibility that the signal might be due to an astrophysical false positive (blend). To aid in this analysis we report the observation of two transits with the Spitzer Space Telescope at 4.5 μm. When combined, they yield a transit depth of 344 ± 85 ppm that is consistent with the depth in the Kepler passband (376 ± 9 ppm, ignoring limb darkening), which rules out blends with an eclipsing binary of a significantly different color than the target. Using these observations along with other constraints from high-resolution imaging and spectroscopy, we are able to exclude the vast majority of possible false positives. We assess the likelihood of the remaining blends, and arrive conservatively at a false alarm rate of 1.6 x 10 -5 that is small enough to validate the candidate as a planet (designated Kepler-10 c) with a very high level of confidence. The radius of this object is measured to be R p = 2.227 +0.052 -0.057 R + (in which the error includes the uncertainty in the stellar properties), but currently available radial-velocity measurements only place an upper limit on its mass of about 20 M + . Kepler-10 c represents another example (with Kepler-9 d and Kepler-11 g) of statistical 'validation' of a transiting exoplanet, as opposed to the usual 'confirmation' that can take place when the Doppler signal is detected or transit timing variations are measured. It is anticipated that many of Kepler's smaller candidates will receive a similar treatment since dynamical confirmation may be difficult or impractical with the sensitivity of

  12. Detection of Potential Transit Signals in the First Three Quarters of Kepler Mission Data

    OpenAIRE

    Tenenbaum, Peter; Christiansen, Jessie L.; Jenkins, Jon M.; Rowe, Jason F.; Seader, Shawn; Caldwell, Douglas A.; Clarke, Bruce D.; Li, Jie; Quintana, Elisa V.; Smith, Jeffrey C.; Stumpe, Martin C.; Thompson, Susan E.; Twicken, Joseph D.; Van Cleve, Jeffrey; Borucki, William J.

    2012-01-01

    We present the results of a search for potential transit signals in the first three quarters of photometry data acquired by the Kepler Mission. The targets of the search include 151,722 stars which were observed over the full interval and an additional 19,132 stars which were observed for only 1 or 2 quarters. From this set of targets we find a total of 5,392 detections which meet the Kepler detection criteria: those criteria are periodicity of the signal, an acceptable signal-to-noise ratio,...

  13. Science from Kepler Collateral Data: 50 Kilosecond per Year from 13 Million Star?

    Science.gov (United States)

    Kolodziejczak, J. J.; Caldwell, D. A.

    2011-01-01

    As each Kepler frame is read out, light from each star in a CCD column accumulates in successive pixels as they wait for the next row to be read out. This accumulation is the same in the masked rows at the start of the readout and virtual rows at the end of the readout as it is in the science data. A range of these "smear" rows are added together for each long cadence and sent to the ground for calibration purposes. We will introduce and describe this smear collateral data, discuss and demonstrate its potential use for scientific studies exclusive of Kepler calibration,.

  14. Multiple star systems observed with CoRoT and Kepler

    Directory of Open Access Journals (Sweden)

    Southworth John

    2015-01-01

    Full Text Available The CoRoT and Kepler satellites were the first space platforms designed to perform high-precision photometry for a large number of stars. Multiple systems display a wide variety of photometric variability, making them natural benefactors of these missions. I review the work arising from CoRoT and Kepler observations of multiple systems, with particular emphasis on eclipsing binaries containing giant stars, pulsators, triple eclipses and/or low-mass stars. Many more results remain untapped in the data archives of these missions, and the future holds the promise of K2, TESS and PLATO.

  15. The Initial Mass Function in the Nearest Strong Lenses from SNELLS: Assessing the Consistency of Lensing, Dynamical, and Spectroscopic Constraints

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Andrew B. [The Observatories of the Carnegie Institution for Science, Pasadena, CA (United States); Smith, Russell J. [Centre for Extragalactic Astronomy, University of Durham, South Road, Durham (United Kingdom); Conroy, Charlie [Department of Astronomy, Harvard University, Cambridge, MA (United States); Villaume, Alexa [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States); Van Dokkum, Pieter, E-mail: anewman@obs.carnegiescience.edu [Department of Astrophysical Sciences, Yale University, New Haven, CT (United States)

    2017-08-20

    We present new observations of the three nearest early-type galaxy (ETG) strong lenses discovered in the SINFONI Nearby Elliptical Lens Locator Survey (SNELLS). Based on their lensing masses, these ETGs were inferred to have a stellar initial mass function (IMF) consistent with that of the Milky Way, not the bottom-heavy IMF that has been reported as typical for high- σ ETGs based on lensing, dynamical, and stellar population synthesis techniques. We use these unique systems to test the consistency of IMF estimates derived from different methods. We first estimate the stellar M {sub *}/ L using lensing and stellar dynamics. We then fit high-quality optical spectra of the lenses using an updated version of the stellar population synthesis models developed by Conroy and van Dokkum. When examined individually, we find good agreement among these methods for one galaxy. The other two galaxies show 2–3 σ tension with lensing estimates, depending on the dark matter contribution, when considering IMFs that extend to 0.08 M {sub ⊙}. Allowing a variable low-mass cutoff or a nonparametric form of the IMF reduces the tension among the IMF estimates to <2 σ . There is moderate evidence for a reduced number of low-mass stars in the SNELLS spectra, but no such evidence in a composite spectrum of matched- σ ETGs drawn from the SDSS. Such variation in the form of the IMF at low stellar masses ( m ≲ 0.3 M {sub ⊙}), if present, could reconcile lensing/dynamical and spectroscopic IMF estimates for the SNELLS lenses and account for their lighter M {sub *}/ L relative to the mean matched- σ ETG. We provide the spectra used in this study to facilitate future comparisons.

  16. Prosthetic soft contact lenses in Japan.

    Science.gov (United States)

    Kanemoto, Masumi; Toshida, Hiroshi; Takahiro, Itagaki; Murakami, Akira

    2007-11-01

    To investigate the use of the prosthetic iris-tinted soft contact lens, the SEED Opaque, during the past 5 years. The records of 42 outpatients (48 eyes) for whom the prosthetic soft contact lens was prescribed in the contact lens clinic of Juntendo University Hospital from July 2001 to June 2005 were investigated. An investigation was conducted in regard to the tint patterns of the prosthetic soft contact lens and the presence or absence of a transparent part in the middle, as a brown iris with a clear pupil or a solid pupil. The diagnosis, purpose of prescription, age when that lens was prescribed, complications, and changes in corrected visual acuities were analyzed retrospectively from the medical records. The mean age at the first prescription, total number of years of wearing prosthetic contact lenses, total number of prescriptions, and mean period to use each SEED Opaque lens were compared. The mean age at the first prescription of solid-pupil lens wearers was significantly younger than that for clear-pupil lens wearers (Ppossible to adjust the color and size of the cosmetic part and the pupil diameter. Further, corrected visual acuities could improve with the clear-pupil type for patients who had prescribed for improvement of visual function.

  17. Efficient lensing element for x-rays

    International Nuclear Information System (INIS)

    Ceglio, N.M.; Smith, H.I.

    1977-01-01

    An efficient x-ray lens with an effective speed of order less than approximately f/50 for lambda greater than approximately 10 A x-rays is described. Fabrication of this lensing element appears feasible using existing microfabrication technology. Diffraction and refraction are coupled in a single element to achieve efficient x-ray concentration into a single order focal spot. Diffraction is used to produce efficient ray bending (without absorption) while refraction is used only to provide appropriate phase adjustment among the various diffraction orders to insure what is essentially a single order output. The mechanism for ray bending (diffraction) is decoupled from the absorption mechanism. Refraction is used only to achieve small shifts in phase so that the associated attenuation need not be prohibitive. The x-ray lens might be described as a Blazed Fresnel Phase Plate (BFPP) with a spatially distributed phase shift within each Fresnel zone. The spatial distribution of the phase shifts is chosen to concentrate essentially all of the unabsorbed energy into a single focal spot. The BFPP transforms the incident plane wave into a converging spherical wave having an amplitude modulation which is periodic in r 2 . As a result of the periodic amplitude modulation, the BFPP will diffract energy into foci other than the first order real focus. In cases of small absorption such effects are negligible and practically all the unabsorbed energy is directed into the first order real focus

  18. Fluid Lensing and Applications to Remote Sensing of Aquatic Environments

    Science.gov (United States)

    Chirayath, Ved

    2017-01-01

    The use of fluid lensing technology on UAVs is presented as a novel means for 3D imaging of aquatic ecosystems from above the water's surface at the centimeter scale. Preliminary results are presented from airborne fluid lensing campaigns conducted over the coral reefs of Ofu Island, American Samoa (2013) and the stromatolite reefs of Shark Bay, Western Australia (2014), covering a combined area of 15km2. These reef ecosystems were revealed with centimetre-scale 2D resolution, and an accompanying 3D bathymetry model was derived using fluid lensing, Structure from Motion and UAV position data. Data products were validated from in-situ survey methods including underwater calibration targets, depth measurements and millimetre-scale high-dynamic range gigapixel photogrammetry. Fluid lensing is an experimental technology that uses water transmitting wavelengths to passively image underwater objects at high-resolution by exploiting time-varying optical lensing events caused by surface waves. Fluid lensing data are captured from low-altitude, cost-effective electric UAVs to achieve multispectral imagery and bathymetry models at the centimetre scale over regional areas. As a passive system, fluid lensing is presently limited by signal-to-noise ratio and water column inherent optical properties to approximately 10 m depth over visible wavelengths in clear waters. The datasets derived from fluid lensing present the first centimetre-scale images of a reef acquired from above the ocean surface, without wave distortion. The 3D multispectral data distinguish coral, fish and invertebrates in American Samoa, and reveal previously undocumented, morphologically distinct, stromatolite structures in Shark Bay. These findings suggest fluid lensing and multirotor electric drones represent a promising advance in the remote sensing of aquatic environments at the centimetre scale, or 'reef scale' relevant to the conservation of reef ecosystems. Pending further development and validation of

  19. Philippus Feselius - Biographical notes on the unknown medicus of Kepler's Tertius Interveniens. (German Title: Philippus Feselius - Biographische Notizen zum unbekannten Medicus aus Keplers Tertius Interveniens)

    Science.gov (United States)

    Lenke, Nils; Roudet, Nicolas

    Until now, Philipp Feselius has been perceived only indirectly as Kepler's antagonist. Not much is known about his life besides his work as Baden private physician and his book against astrology which was cited intensely in Kepler's «Tertius Interveniens». This paper traces the stations of his career as a physician, about his presumable provenance and education in Strasbourg, his academic career in Tübingen, Strasbourg, Rostock and Padua, the doctorate in Basel in 1592, up to his employment, in 1599, as a court physician in Sulzburg and later in Durlach. Further hand-written and printed traces of Feselius are presented, and his social environment is investigated so that his personality becomes clearer, and relations can be established between his education and his writing against astrology.

  20. Characterizing Lenses and Lensed Stars of High-magnification Single-lens Gravitational Microlensing Events with Lenses Passing over Source Stars

    DEFF Research Database (Denmark)

    Choi, J.-Y; Park, S.-Y; Han, C.

    2012-01-01

    -source effect. For seven events, we measure the Einstein radii and the lens-source relative proper motions. Among them, five events are found to have Einstein radii of less than 0.2 mas, making the lenses very low mass star or brown dwarf candidates. For MOA-2011-BLG-274, especially, the small Einstein radius...

  1. Investigating the Properties of Granulation in the Red Giants Observed by Kepler

    DEFF Research Database (Denmark)

    Mathur, S.; Hekker, S.; Trampedach, R.

    2012-01-01

    More than 1000 red giants have been observed by NASA/Kepler mission during a nearly continuous period of ˜ 13 months. The resulting high-frequency resolution (<0.03 μHz) allows us to study the granulation parameters of these stars. The granulation pattern results from the convection motions leadi...

  2. Kepler Planet Detection Metrics: Window and One-Sigma Depth Functions for Data Release 25

    Science.gov (United States)

    Burke, Christopher J.; Catanzarite, Joseph

    2017-01-01

    This document describes the window and one-sigma depth functions relevant to the Transiting Planet Search (TPS) algorithm in the Kepler pipeline (Jenkins 2002; Jenkins et al. 2017). The window function specifies the fraction of unique orbital ephemeris epochs over which three transits are observable as a function of orbital period. In this context, the epoch and orbital period, together, comprise the ephemeris of an orbiting companion, and ephemerides with the same period are considered equivalent if their epochs differ by an integer multiple of the period. The one-sigma depth function specifies the depth of a signal (in ppm) for a given light curve that results in a one-sigma detection of a transit signature as a function of orbital period when averaged over all unique orbital ephemerides. These planet detection metrics quantify the ability of TPS to detect a transiting planet signature on a star-by-star basis. They are uniquely applicable to a specific Kepler data release, since they are dependent on the details of the light curves searched and the functionality of the TPS algorithm used to perform the search. This document describes the window and one-sigma depth functions relevant to Kepler Data Release 25 (DR25), where the data were processed (Thompson et al. 2016) and searched (Twicken et al. 2016) with the SOC 9.3 pipeline. In Section 4, we describe significant differences from those reported in Kepler Data Release 24 (Burke Seader 2016) and document our verification method.

  3. Automated preparation of Kepler time series of planet hosts for asteroseismic analysis

    DEFF Research Database (Denmark)

    Handberg, R.; Lund, M. N.

    2014-01-01

    . In this paper we present the KASOC Filter, which is used to automatically prepare data from the Kepler/K2 mission for asteroseismic analyses of solar-like planet host stars. The methods are very effective at removing unwanted signals of both instrumental and planetary origins and produce significantly cleaner...

  4. VizieR Online Data Catalog: Kepler pipeline transit signal recovery. III. (Christiansen+, 2016)

    Science.gov (United States)

    Christiansen, J. L.; Clarke, B. D.; Burke, C. J.; Jenkins, J. M.; Bryson, S. T.; Coughlin, J. L.; Mullally, F.; Thompson, S. E.; Twicken, J. D.; Batalha, N. M.; Haas, M. R.; Catanzarite, J.; Campbell, J. R.; Uddin, A. K.; Zamudio, K.; Smith, J. C.; Henze, C. E.

    2018-03-01

    Here we describe the third transit injection experiment, which tests the entire Kepler observing baseline (Q1-Q17) for the first time across all 84 CCD channels. It was performed to measure the sensitivity of the Kepler pipeline used to generate the Q1-Q17 Data Release 24 (DR24) catalog of Kepler Objects of Interest (Coughlin et al. 2016, J/ApJS/224/12) available at the NASA Exoplanet Archive (Akeson et al. 2013PASP..125..989A). The average detection efficiency describes the likelihood that the Kepler pipeline would successfully recover a given transit signal. To measure this property we perform a Monte Carlo experiment where we inject the signatures of simulated transiting planets around 198154 target stars, one per star, across the focal plane starting with the Q1-Q17 DR24 calibrated pixels. The simulated transits are generated using the Mandel & Agol (2002ApJ...580L.171M) model. Of the injections, 159013 resulted in three or more injected transits (the minimum required for detection by the pipeline) and were used for the subsequent analysis. (1 data file).

  5. VizieR Online Data Catalog: Parameters of 529 Kepler eclipsing binaries (Kjurkchieva+, 2017)

    Science.gov (United States)

    Kjurkchieva, D.; Vasileva, D.; Atanasova, T.

    2017-11-01

    We reviewed the Kepler eclipsing binary catalog (Prsa et al. 2011, Cat. J/AJ/141/83; Slawson et al. 2011, Cat. J/AJ/142/160; Matijevic et al. 2012) to search for detached eclipsing binaries with eccentric orbits. (5 data files).

  6. Jacobi's last multiplier and symmetries for the Kepler problem plus a lineal story

    International Nuclear Information System (INIS)

    Nucci, M C; Leach, P G L

    2004-01-01

    We calculate the first integrals of the Kepler problem by the method of Jacobi's last multiplier using the symmetries for the equations of motion. Also we provide another example which shows that Jacobi's last multiplier together with Lie symmetries unveils many first integrals neither necessarily algebraic nor rational whereas other published methods may yield just one

  7. Solar-like oscillations in KIC 11395018 and KIC 11234888 from 8 months of Kepler data

    NARCIS (Netherlands)

    Mathur, S.; Handberg, R.; Campante, T.L.; Garcia, R.A.; Appourchaux, T.; Bedding, T.R.; Mosser, B.; Chaplin, W.J.; Ballot, J.; Benomar, O.; Bonanno, A.; Corsaro, E.; Gaulme, P.; Hekker, S.; Regulo, C.; Salabert, D.; Verner, G.; White, T.R.; Brandao, I.M.; Creevey, O.L.; Dogan, G.; Elsworth, Y.; Huber, D.; Hale, S.J.; Houdek, G.; Karoff, C.; Metcalfe, T.S.; Molenda-Zakowicz, J.; Monteiro, M.J.P.F.G.; Thompson, M.J.; Christensen-Dalsgaard, J.; Gilliland, R.L.; Kawaler, S.D.; Kjeldsen, H.; Quintana, E.V.; Sanderfer, D.T.; Seader, S.E.

    2011-01-01

    We analyze the photometric short-cadence data obtained with the Kepler mission during the first 8 months of observations of two solar-type stars of spectral types G and F: KIC 11395018 and KIC 11234888, respectively, the latter having a lower signal-to-noise ratio (S/N) compared with the former. We

  8. Seismic analysis of four solar-like stars observed during more than eight months by Kepler

    NARCIS (Netherlands)

    Mathur, S.; Campante, T.L.; Handberg, R.; García, R.A.; Appourchaux, T.; Bedding, T.R.; Mosser, B.; Chaplin, W.J.; Ballot, J.; Benomar, O.; Bonanno, A.; Corsaro, E.; Gaulme, P.; Hekker, S.; Régulo, C.; Salabert, D.; Verner, G.; White, T.R.; Brandão, I.M.; Creevey, O.L.; Doğan, G.; Bazot, M.; Cunha, M.S.; Elsworth, Y.; Huber, D.; Hale, S.J.; Houdek, G.; Karoff, C.; Lundkvist, M.; Metcalfe, T.S.; Molenda-Żakowicz, J.; Monteiro, M.J.P.F.G.; Thompson, M.J.; Stello, D.; Christensen-Dalsgaard, J.; Gilliland, R.L.; Kawaler, S.D.; Kjeldsen, H.; Clarke, B.D.; Girouard, F.R.; Hall, J.R.; Quintana, E.V.; Sanderfer, D.T.; Seader, S.E.

    2012-01-01

    Having started science operations in May 2009, the Kepler photometer has been able to provide exquisite data of solar-like stars. Five out of the 42 stars observed continuously during the survey phase show evidence of oscillations, even though they are rather faint (magnitudes from 10.5 to 12). In

  9. Rotation and oblique pulsation in Kepler observations of the roAp star KIC 10483436

    DEFF Research Database (Denmark)

    Balona, L. A.; Cunha, M. S.; Gruberbauer, M.

    2011-01-01

    Photometry of KIC 10483436 was obtained continuously with 1-min exposures over a 27-d period from the Kepler satellite. The light curve shows rotational variations from surface spots with a period of 4.303 ± 0.002 d, an amplitude of about 6 mmag and eight pulsation frequencies typical of roAp sta...

  10. Seismic analysis of four solar-like stars observed during more than eight months by Kepler

    DEFF Research Database (Denmark)

    Mathur, S.; L. Campante, T.; Handberg, R.

    2011-01-01

    Having started science operations in May 2009, the Kepler photometer has been able to provide exquisite data of solar-like stars. Five out of the 42 stars observed continuously during the survey phase show evidence of oscillations, even though they are rather faint (magnitudes from 10.5 to 12). I...

  11. Detailed Study of the Internal Structure of a Red-giant Star Observed with Kepler

    DEFF Research Database (Denmark)

    Di Mauro, M. P.; Ventura, R.; Cardini, D.

    2012-01-01

    We study the internal structure and evolutionary state of KIC 4351319, a red-giant star observed with the Kepler satellite. The use of 25 individual oscillation frequencies, together with the accurate atmospheric data provided by ground-based spectroscopic observations, allowed us to estimate the...

  12. Asteroseismology of Red Giants from the First Four Months of Kepler Data

    DEFF Research Database (Denmark)

    Huber, Daniel; Bedding, Timothy R.; Stello, Dennis

    2010-01-01

    We have studied solar-like oscillations in ~800 red giant stars using Kepler long-cadence photometry. The sample includes stars ranging in evolution from the lower part of the red giant branch to the helium main sequence. We investigate the relation between the large frequency separation (Δν) and...

  13. Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data

    DEFF Research Database (Denmark)

    Batalha, Natalie M.; Rowe, Jason F.; Bryson, Stephen T.

    2012-01-01

    New transiting planet candidates are identified in sixteen months (May 2009 - September 2010) of data from the Kepler spacecraft. Nearly five thousand periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1,091 viable new planet candidates, bring...

  14. Using Final Kepler Catalog Completeness and Reliability Products in Exoplanet Occurrence Rate Estimates

    Science.gov (United States)

    Bryson, Steve; Burke, Christopher; Batalha, Natalie Marie; Thompson, Susan E.; Coughlin, Jeffrey; Christiansen, Jessie; Mullally, Fergal; Shabram, Megan; Kepler Team

    2018-01-01

    Burke et. al. 2015 presented an exoplanet occurrence rate estimate based on the Q1-Q16 Kepler Planet Candidate catalog. That catalog featured uniform planet candidate vetting and analytic approximations to the detection completeness (the fraction of true planets that would be detected) for each target star. We present an extension of that occurrence rate work using the final DR25 Kepler Planet Candidate catalog products, which uses higher-accuracy detection completeness data for each target star, and adds estimates of vetting completeness (the fraction of detected true planets correctly identified as planet candidates) and vetting reliability (the fraction of planet candidates that are true planets). These completeness and reliability products are based on synthetic manipulations of Kepler data, including transit injection, data scrambling, and inversion. We describe how each component is incorporated into the occurrence rate estimate, and how they impact the occurrence rate estimate both individually and in combination. We discuss the strengths and weaknesses of the completeness and reliability products and how they impact our confidence in the occurrence rate values uncertainties. This work is an example of how the community can use the DR25 completeness and reliability products, which are publicly available at the NASA Exoplanet Archive (http://exoplanetarchive.ipac.caltech.edu) and the Mikulski Archive for Space Telescopes (http://archive.stsci.edu/kepler).

  15. KEGS Transients Discovered by a Pan-STARRS1 Search of the Kepler Campaign 16 Field

    Science.gov (United States)

    Smith, K. W.; Rest, A.; Tucker, B. E.; Garnavich, P. M.; Margheim, S.; Kasen, D.; Olling, R.; Shaya, E.; Narayan, G.; Villar, A.; Forster, F.; Mushotzky, R.; Zenteno, A.; James, D.; Smith, R. Chris; Dotson, J. L.; Barentsen, G.; Gully-Santiago, M.; Smartt, S. J.; Wright, D. E.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Schultz, A.; Magnier, E.; Waters, C.; Bulger, J.; Wainscoat, R. J.

    2018-01-01

    We report the following transients discovered by Pan-STARRS1 during a targeted search of the Kepler Campaign 16 field as part of the K2 Extragalactic Survey (KEGS) for Transients (see http://www.mso.anu.edu.au/kegs/).

  16. Periodic solutions of an indefinite singular equation arising from the Kepler problem on the sphere

    Czech Academy of Sciences Publication Activity Database

    Hakl, Robert; Zamora, M.

    2018-01-01

    Roč. 70, č. 1 (2018), s. 173-190 ISSN 0008-414X Institutional support: RVO:67985840 Keywords : indefinite singularity * periodic solution * Kepler problem on S^1 Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 0.963, year: 2016 https://cms.math.ca/10.4153/CJM-2016-050-1

  17. Transiting Exoplanet Monitoring Project (TEMP). III. On the Relocation of the Kepler-9 b Transit

    Science.gov (United States)

    Wang, Songhu; Wu, Dong-Hong; Addison, Brett C.; Laughlin, Gregory; Liu, Hui-Gen; Wang, Yong-Hao; Yang, Taozhi; Yang, Ming; Yisikandeer, Abudusaimaitijiang; Hong, Renquan; Li, Bin; Liu, Jinzhong; Zhao, Haibin; Wu, Zhen-Yu; Hu, Shao-Ming; Zhou, Xu; Zhou, Ji-Lin; Zhang, Hui; Zheng, Jie; Wang, Wei; Fan, Zhou; Niu, Hubiao; Chen, Yuan-Yuan; Lu, Hao; Peng, Xiyan; Li, Kai; Guo, Di-Fu

    2018-02-01

    The Kepler-9 system harbors three known transiting planets. The system holds significant interest for several reasons. First, the outer two planets exhibit a period ratio that is close to a 2:1 orbital commensurability, with attendant dynamical consequences. Second, both planets lie in the planetary mass “desert” that is generally associated with the rapid gas agglomeration phase of the core accretion process. Third, there exist attractive prospects for accurately measuring both the sky-projected stellar spin–orbit angles as well as the mutual orbital inclination between the planets in the system. Following the original Kepler detection announcement in 2010, the initially reported orbital ephemerides for Kepler-9 b and c have degraded significantly, due to the limited time base-line of observations on which the discovery of the system rested. Here, we report new ground-based photometric observations and extensive dynamical modeling of the system. These efforts allow us to photometrically recover the transit of Kepler-9 b and thereby greatly improve the predictions for upcoming transit mid-times. Accurate ephemerides of this system are important in order to confidently schedule follow-up observations of this system, for both in-transit Doppler measurements as well as for atmospheric transmission spectra taken during transit.

  18. The connection between stellar granulation and oscillation as seen by the Kepler mission

    NARCIS (Netherlands)

    Kallinger, T.; De Ridder, J.; Hekker, S.; Mathur, S.; Mosser, B.; Gruberbauer, M.; García, R.A.; Karoff, C.; Ballot, J.

    2014-01-01

    Context. The long and almost continuous observations by Kepler show clear evidence of a granulation background signal in a large sample of stars, which is interpreted as the surface manifestation of convection. It has been shown that its characteristic timescale and rms intensity fluctuation scale

  19. CoRoT and Kepler results: Solar-like oscillators

    NARCIS (Netherlands)

    Hekker, S.

    2013-01-01

    The space-borne observatories CoRoT (Convection Rotation and planetary Transits) and Kepler have provided photometric time series data of unprecedented precision for large numbers of stars. These data have revolutionized the fields of transiting exoplanets and asteroseismology. In this review some

  20. Automated Classification of Variable Stars in the Asteroseismology Program of the Kepler Space Mission

    DEFF Research Database (Denmark)

    Blomme, J.; Debosscher, J.; De Ridder, J.

    2010-01-01

    We present the first results of the application of supervised classification methods to the Kepler Q1 long-cadence light curves of a subsample of 2288 stars measured in the asteroseismology program of the mission. The methods, originally developed in the framework of the CoRoT and Gaia space...

  1. Predicting the Detectability of Oscillations in Solar-type Stars Observed by Kepler

    DEFF Research Database (Denmark)

    Chaplin, William J.; Kjeldsen, Hans; Bedding, Timothy R.

    2011-01-01

    Asteroseismology of solar-type stars has an important part to play in the exoplanet program of the NASA Kepler Mission. Precise and accurate inferences on the stellar properties that are made possible by the seismic data allow very tight constraints to be placed on the exoplanetary systems. Here...

  2. Kepler-1649b: An Exo-Venus in the Solar Neighborhood

    Energy Technology Data Exchange (ETDEWEB)

    Angelo, Isabel; Rowe, Jason F.; Huber, Daniel [SETI Institute, Mountain View, CA 94043 (United States); Howell, Steve B.; Quintana, Elisa V.; Burningham, Ben; Barclay, Thomas [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Still, Martin [Bay Area Environmental Research Institute, 625 2nd Street, Suite 209, Petaluma, CA 94952 (United States); Mann, Andrew W. [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA (United States); Kane, Stephen R., E-mail: isabelangelo@berkeley.edu [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States)

    2017-04-01

    The Kepler mission has revealed that Earth-sized planets are common, and dozens have been discovered to orbit in or near their host star’s habitable zone. A major focus in astronomy is to determine which of these exoplanets are likely to have Earth-like properties that are amenable to follow-up with both ground- and future space-based surveys, with an ultimate goal of probing their atmospheres to look for signs of life. Venus-like atmospheres will be of particular interest in these surveys. While Earth and Venus evolved to have similar sizes and densities, it remains unclear what factors led to the dramatic divergence of their atmospheres. Studying analogs to both Earth and Venus can thus shed light on the limits of habitability and the potential for life on known exoplanets. Here, we present the discovery and confirmation of Kepler-1649b, an Earth-sized planet orbiting a nearby M5V star that receives incident flux at a level similar to that of Venus. We present our methods for characterizing the star, using a combination of point-spread function photometry, ground-based spectroscopy, and imaging, to confirm the planetary nature of Kepler-1649b. Planets like Kepler-1649b will be prime candidates for atmospheric and habitability studies in the next generation of space missions.

  3. Investigating the Properties of Granulation in the Red Giants Observed by Kepler

    NARCIS (Netherlands)

    Mathur, S.; Hekker, S.; Trampedach, R.; Ballot, J.; Kallinger, T.; Buzasi, D.; García, R.A.; Huber, D.; Jiménez, A.; Mosser, B.; Bedding, T.R.; Elsworth, Y.; Régulo, C.; Stello, D.; Chaplin, W.J.; De Ridder, J.; Hale, S.J.; Kinemuchi, K.; Kjeldsen, H.; Mullally, F.; Thompson, S.E.

    2012-01-01

    More than 1000 red giants have been observed by NASA/Kepler mission during a nearly continuous period of ˜ 13 months. The resulting high-frequency resolution (< 0.03 μHz) allows us to study the granulation parameters of these stars. The granulation pattern results from the convection motions leading

  4. Solar-like Oscillations in KIC 11395018 and KIC 11234888 from 8 Months of Kepler Data

    DEFF Research Database (Denmark)

    Mathur, S.; Handberg, Rasmus; Campante, Tiago. L.

    2011-01-01

    We analyze the photometric short-cadence data obtained with the Kepler mission during the first 8 months of observations of two solar-type stars of spectral types G and F: KIC 11395018 and KIC 11234888, respectively, the latter having a lower signal-to-noise ratio (S/N) compared with the former. We...

  5. Predicting the detectability of oscillations in solar-type stars observed by Kepler

    NARCIS (Netherlands)

    Chaplin, W.J.; Kjeldsen, H.; Bedding, T.R.; Christensen-Dalsgaard, J.; Gilliland, R.L.; Kawaler, S.D.; Appourchaux, T.; Elsworth, Y.; Garcia, R.A.; Houdek, G.; Karoff, C.; Metcalfe, T.S.; Molenda-Zakowicz, J.; Monteiro, M.J.P.F.G.; Thompson, M.J.; Verner, G.A.; Batalha, N.; Borucki, W.J.; Brown, T.M.; Bryson, S.T.; Christiansen, J.L.; Clarke, B.D.; Jenkins, J.M.; Klaus, T.C.; Koch, D.; An, D.; Ballot, J.; Basu, S.; Benomar, O.; Bonanno, A.; Broomhall, A.M.; Campante, T.L.; Corsaro, E.; Creevey, O.L.; Esch, L.; Gai, N.; Gaulme, P.; Hale, S.J.; Handberg, R.; Hekker, S.; Huber, D.; Mathur, S.; Mosser, B.; New, R.; Pinsonneault, M.H.; Pricopi, D.; Quirion, P.O.; Regulo, C.; Roxburgh, I.W.; Salabert, D.; Stello, D.; Suran, M.D.

    2011-01-01

    Asteroseismology of solar-type stars has an important part to play in the exoplanet program of the NASA Kepler Mission. Precise and accurate inferences on the stellar properties that are made possible by the seismic data allow very tight constraints to be placed on the exoplanetary systems. Here, we

  6. Bergman kernels, TYZ expansions and Hankel operators on the Kepler manifold

    Czech Academy of Sciences Publication Activity Database

    Bommier-Hato, H.; Engliš, Miroslav; Youssfi, E.-H.

    2016-01-01

    Roč. 271, č. 2 (2016), s. 264-288 ISSN 0022-1236 Institutional support: RVO:67985840 Keywords : Kepler manifold * Bergman kernel * Tian-Yau-Zelditch expansion Subject RIV: BA - General Mathematics Impact factor: 1.254, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022123616300593

  7. Keplerův Novoroční dar krystalografii

    Czech Academy of Sciences Publication Activity Database

    Fábry, Jan

    2012-01-01

    Roč. 62, č. 4 (2012), s. 253-255 ISSN 0009-0700 Institutional research plan: CEZ:AV0Z10100520 Keywords : Johannes Kepler * Strena Seu de nive sexangula * six-cornered snow-flakes * close-packed arrangements of spheres Subject RIV: AB - History

  8. Revised Stellar Properties of Kepler Targets for the Quarter 1-16 Transit Detection Run

    NARCIS (Netherlands)

    Huber, D.; Silva Aguirre, V.; Matthews, J.M.; Pinsonneault, M.H.; Gaidos, E.; García, R.A.; Hekker, S.; Mathur, S.; Mosser, B.; Torres, G.; Bastien, F.A.; Basu, S.; Bedding, T.R.; Chaplin, W.J.; Demory, B.O.; Fleming, S.W.; Guo, Z.; Mann, A.W.; Rowe, J.F.; Serenelli, A.M.; Smith, M.A.; Stello, D.

    2014-01-01

    We present revised properties for 196,468 stars observed by the NASA Kepler mission and used in the analysis of Quarter 1-16 (Q1-Q16) data to detect and characterize transiting planets. The catalog is based on a compilation of literature values for atmospheric properties (temperature, surface

  9. Detailed Study of the Internal Structure of a Red-giant Star Observed with Kepler

    NARCIS (Netherlands)

    Di Mauro, M.P.; Ventura, R.; Cardini, D.; Catanzaro, G.; Barban, C.; Bedding, T.R.; Christensen-Dalsgaard, J.; De Ridder, J.; Hekker, S.; Huber, D.; Kallinger, T.; Kinemuchi, K.; Kjeldsen, H.; Miglio, A.; Montalbán, J.; Mosser, B.; Mullally, F.; Stello, D.; Still, M.; Uytterhoeven, K.

    2012-01-01

    We study the internal structure and evolutionary state of KIC 4351319, a red-giant star observed with the Kepler satellite. The use of 25 individual oscillation frequencies, together with the accurate atmospheric data provided by ground-based spectroscopic observations, allowed us to estimate the

  10. Stellar hydrodynamics caught in the act: Asteroseismology with CoRoT and Kepler

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jørgen; Thompson, Michael J.

    2011-01-01

    Asteroseismic investigations, particularly based on data on stellar oscillations from the CoRoT and Kepler space missions, are providing unique possibilities for investigating the properties of stellar interiors. This constitutes entirely new ways to study the effects of dynamic phenomena...

  11. Mass and age of red giant branch stars observed with LAMOST and Kepler

    DEFF Research Database (Denmark)

    Wu, Yaqian; Xiang, Maosheng; Bi, Shaolan

    2018-01-01

    Obtaining accurate and precise masses and ages for large numbers of giant stars is of great importance for unraveling the assemblage history of the Galaxy. In this paper, we estimate masses and ages of 6940 red giant branch (RGB) stars with asteroseismic parameters deduced from Kepler photometry...

  12. Oscillation mode frequencies of 61 main-sequence and subgiant stars observed by Kepler

    DEFF Research Database (Denmark)

    Appourchaux, T.; Chaplin, W. J.; García, R. A.

    2012-01-01

    Solar-like oscillations have been observed by Kepler and CoRoT in several solar-type stars, thereby providing a way to probe the stars using asteroseismology Aims. We provide the mode frequencies of the oscillations of various stars required to perform a comparison with those obtained from stellar...

  13. Age of the Kepler Open Cluster NGC 6811 from an Eclipsing Binary

    DEFF Research Database (Denmark)

    Leitner, Marika; Sandquist, E. L.; Shetrone, M. D.

    2013-01-01

    The star KIC9777062 was discovered to be an eccentric eclipsing binary star via Kepler observations (Prsa et al. 2011). Because the system (also identified as Sanders 195) sits at the turnoff of the open cluster NGC 6811, precision measurement of the characteristics of the stars in the binary can...

  14. Probing the Deep End of the Milky Way with New Oscillating Kepler Giants

    Science.gov (United States)

    Mathur, Savita; García, Rafael A.; Huber, Daniel; Regulo, Clara; Stello, Dennis; Beck, Paul G.; Houmani, Kenza; Salabert, David

    2017-10-01

    The Kepler mission has been a success in both exoplanet search and stellar physics studies. Red giants have actually been quite a highlight in the Kepler scene. The Kepler long and almost continuous four-year observations allowed us to detect oscillations in more than 15,000 red giants targeted by the mission. However by looking at the power spectra of 45,000 stars classified as dwarfs according to the Q1-16 Kepler star properties catalog, we detected red-giant like oscillations in 850 stars. Even though this is a small addition to the known red-giant sample, these misclassified stars represent a goldmine for galactic archeology studies. Indeed they happen to be fainter (down to Kp 16) and more distant (d>10kPc) than the known red giants, opening the possibility to probe unknown regions of our Galaxy. The faintness of these red giants with detected oscillations is very promising for detecting acoustic modes in red giants observed with K2 and TESS. In this talk, I will present this new sample of red giants with their revised stellar parameters derived from asteroseismology. Then I will discuss about the distribution of their masses, distances, and evolutionary states compared to the previously known sample of red giants.

  15. Flat liquid crystal diffractive lenses with variable focus and magnification

    Science.gov (United States)

    Valley, Pouria

    Non-mechanical variable lenses are important for creating compact imaging devices. Various methods employing dielectrically actuated lenses, membrane lenses, and liquid crystal lenses were previously proposed [1-4]. In This dissertation the design, fabrication, and characterization of innovative flat tunable-focus liquid crystal diffractive lenses (LCDL) are presented. LCDL employ binary Fresnel zone electrodes fabricated on Indium-Tin-Oxide using conventional micro-photolithography. The light phase can be adjusted by varying the effective refractive index of a nematic liquid crystal sandwiched between the electrodes and a reference substrate. Using a proper voltage distribution across various electrodes the focal length can be changed between several discrete values. Electrodes are shunted such that the correct phase retardation step sequence is achieved. If the number of 2pi zone boundaries is increased by a factor of m the focal length is changed from f to f/m based on the digitized Fresnel zone equation: f = rm2/2mlambda, where r m is mth zone radius, and lambda is the wavelength. The chromatic aberration of the diffractive lens is addressed and corrected by adding a variable fluidic lens. These LCDL operate at very low voltage levels (+/-2.5V ac input), exhibit fast switching times (20-150 ms), can have large apertures (>10 mm), and small form factor, and are robust and insensitive to vibrations, gravity, and capillary effects that limit membrane and dielectrically actuated lenses. Several tests were performed on the LCDL including diffraction efficiency measurement, switching dynamics, and hybrid imaging with a refractive lens. Negative focal lengths are achieved by adjusting the voltages across electrodes. Using these lenses in combination, magnification can be changed and zoom lenses can be formed. These characteristics make LCDL a good candidate for a variety of applications including auto-focus and zoom lenses in compact imaging devices such as camera

  16. Comparison between liquid and solid tunable focus lenses

    Energy Technology Data Exchange (ETDEWEB)

    Santiago-Alvarado, A; Cruz-Martinez, V M [Universidad Tecnologica de la Mixteca, Carre. Acatlima Km 2.5 Huajuapan de Leon Oaxaca (Mexico); Vazquez-Montiel, S; Munoz-Lopez, J; Diaz-Gonzalez, G [Instituto Nacional de Astrofisica, Optica y Electronica Luis Enrique Erro 1, Tonantzintla Puebla (Mexico); Campos-Garcia, M, E-mail: santiago@mixteco.utm.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apdo. Postal 70-186, 04510, D.F. Mexico (Mexico)

    2011-01-01

    Nowadays more reports in the use of tunable lenses are reported, it is due to the benefits they offer in optical systems design. A tunable lens is an optical system that can focus on a range of positions by changing dynamically one of its geometric parameters. There are several types of tunable lenses, the most known types are the liquid, the solid elastic, with variable refractive index, and lenses that use a dielectric medium. This paper presents the analysis and opto-mechanical design of two tunable lenses, a liquid lens and another Solid Elastic Lens (SEL). Both lenses are made in mounting aluminium and polydimethylsiloxane (PDMS) as refractor medium, the liquid lens use two elastic membranes containing a liquid medium between them while the SEL only use PDMS material as body of the lens (medium refractor). We describe the opto-mechanical performance of both types of lens highlighting the main features of each. Finally, results of a opto-functional comparison between these prototypes are showed.

  17. Advances in scleral lenses for refractive surgery complications.

    Science.gov (United States)

    Parminder, Amy; Jacobs, Deborah S

    2015-07-01

    The last two decades have brought advances in materials and manufacturing of large diameter rigid gas-permeable contact lenses, and a greater appreciation of the role of scleral lenses for therapeutic indications. The purpose of this review is to provide an update on the use of rigid gas-permeable scleral lenses in the management of patients with complications after refractive surgery. There are recent reports on clinical experience with specific scleral lens designs from single institutions in cohorts that include patients who have undergone refractive surgery. Typically, these are patients with 'irregular corneas' after radial keratotomy or LASER assisted in-situ keratomileusis, but patients with keratectasia, dry eye syndrome, and corneal neuralgia are also reported. Visual outcomes and wearing success rates are high in these reports, although outcomes for refractive surgery patients are not reported separately. Clinicians who encounter patients with complications after corneal refractive surgery should be aware of advances in scleral lenses. Scleral lenses are an alternative to surgical intervention in patients who might otherwise be considered poor contact lens candidates.

  18. Bacterial adherence to extended wear soft contact lenses

    International Nuclear Information System (INIS)

    Aswad, M.I.; John, T.; Barza, M.; Kenyon, K.; Baum, J.

    1990-01-01

    The authors studied the adherence of Pseudomonas aeruginosa and Staphylococcus aureus to extended wear soft contact lenses (EWSCLs) with and without focal deposits using both a radiolabeling technique and electron microscopy. P. aeruginosa showed significant adherence to contact lenses in vitro. In contrast, S. aureus failed to show significant adherence to contact lenses in vitro (i.e., the radioactive uptake was not significantly above background). The extent of adherence of Pseudomonas was proportional to the number of focal deposits on the lenses. Results of electron microscopic examination showed the bacteria to be adherent primarily to large focal deposits (greater than or equal to 150 microns). There was no pseudomonal adherence to the small focal deposits (less than or equal to 50 microns) and little adherence to the areas in between the focal deposits. The authors hypothesize that worn lenses, especially those with large focal deposits, serve as a vehicle for the transport of P. aeruginosa to the cornea. This hypothesis could be a partial explanation for the high incidence of keratitis caused by P. aeruginosa in EWSCL patients

  19. The First APOKASC Catalog of Kepler Dwarf and Subgiant Stars

    Science.gov (United States)

    Serenelli, Aldo; Johnson, Jennifer; Huber, Daniel; Pinsonneault, Marc; Ball, Warrick H.; Tayar, Jamie; Silva Aguirre, Victor; Basu, Sarbani; Troup, Nicholas; Hekker, Saskia; Kallinger, Thomas; Stello, Dennis; Davies, Guy R.; Lund, Mikkel N.; Mathur, Savita; Mosser, Benoit; Stassun, Keivan G.; Chaplin, William J.; Elsworth, Yvonne; García, Rafael A.; Handberg, Rasmus; Holtzman, Jon; Hearty, Fred; García-Hernández, D. A.; Gaulme, Patrick; Zamora, Olga

    2017-12-01

    We present the first APOKASC catalog of spectroscopic and asteroseismic data for dwarfs and subgiants. Asteroseismic data for our sample of 415 objects have been obtained by the Kepler mission in short (58.5 s) cadence, and light curves span from 30 up to more than 1000 days. The spectroscopic parameters are based on spectra taken as part of the Apache Point Observatory Galactic Evolution Experiment and correspond to Data Release 13 of the Sloan Digital Sky Survey. We analyze our data using two independent {T}{eff} scales, the spectroscopic values from DR13 and those derived from SDSS griz photometry. We use the differences in our results arising from these choices as a test of systematic temperature uncertainties and find that they can lead to significant differences in the derived stellar properties. Determinations of surface gravity ({log}g), mean density ( ), radius (R), mass (M), and age (τ) for the whole sample have been carried out by means of (stellar) grid-based modeling. We have thoroughly assessed random and systematic error sources in the spectroscopic and asteroseismic data, as well as in the grid-based modeling determination of the stellar quantities provided in the catalog. We provide stellar properties determined for each of the two {T}{eff} scales. The median combined (random and systematic) uncertainties are 2% (0.01 dex; {log}g), 3.4% ( ), 2.6% (R), 5.1% (M), and 19% (τ) for the photometric {T}{eff} scale and 2% ({log}g), 3.5% ( ), 2.7% (R), 6.3% (M), and 23% (τ) for the spectroscopic scale. We present comparisons with stellar quantities in the asteroseismic catalog by Chaplin et al. that highlight the importance of having metallicity measurements for determining stellar parameters accurately. Finally, we compare our results with those coming from a variety of sources, including stellar radii determined from TGAS parallaxes and asteroseismic analyses based on individual frequencies. We find a very good agreement for all inferred quantities

  20. Aldose reductase activity and glucose-related opacities in incubated lenses from dogs and cats.

    Science.gov (United States)

    Richter, Marianne; Guscetti, Franco; Spiess, Bernhard

    2002-11-01

    To determine responses of canine and feline lenses to incubation in a medium with a high glucose concentration. Lenses from 35 dogs and 26 cats. Glucose concentrations were measured in paired lenses from 25 dogs and 17 cats after incubation for 14 days in high-glucose (30 mmol of glucose/L) or control (6 mmol of glucose/L) medium. Aldose reductase activity was measured spectrophotometrically in the incubated lenses and in freshly frozen lenses from 10 dogs and 9 cats. Two lenses of each group were studied histologically. Canine and feline lenses in high-glucose medium developed glucose-specific opacities of variable localization and extent. Canine lenses developed equatorial vacuoles, but severity of the lesions was not associated with the age of the dog. Lenses from young cats (cats (> 4 years old) did not. Glucose concentrations were similar in all lenses incubated in high-glucose medium; however aldose reductase activity was significantly lower in lenses from older cats, compared with lenses from young cats and from dogs. High aldose reductase activity and glucose-related opacities suggest a central role for this enzyme in the pathogenesis of diabetic cataracts in dogs and cats. Because onset of diabetes mellitus usually occurs in cats > 7 years of age, low activity of aldose reductase in lenses of older cats may explain why diabetic cataracts are rare in this species despite hyperglycemia.

  1. VizieR Online Data Catalog: Final Kepler transiting planet search (DR25) (Twicken+, 2016)

    Science.gov (United States)

    Twicken, J. D.; Jenkins, J. M.; Seader, S. E.; Tenenbaum, P.; Smith, J. C.; Brownston, L. S.; Burke, C. J.; Catanzarite, J. H.; Clarke, B. D.; Cote, M. T.; Girouard, F. R.; Klaus, T. C.; Li, J.; McCauliff, S. D.; Morris, R. L.; Wohler, B.; Campbell, J. R.; Uddin, A. K.; Zamudio, K. A.; Sabale, A.; Bryson, S. T.; Caldwell, D. A.; Christiansen, J. L.; Coughlin, J. L.; Haas, M. R.; Henze, C. E.; Sanderfer, D. T.; Thompson, S. E.

    2017-01-01

    The Kepler spacecraft is in an Earth-trailing heliocentric orbit and maintained a boresight pointing centered on α=19h22m40s, δ=+44.5° during the primary mission. The Kepler photometer acquired data on a 115-square-degree region of the sky. The data were acquired on 29.4-minute intervals, colloquially known as "long cadences". Long-cadence pixel values were obtained by accumulating 270 consecutive 6.02s exposures. Science acquisition of Q1 data began at 2009-05-13 00:01:07Z, and acquisition of Q17 data concluded at 2013-05-11 12:16:22Z. This time period contains 71427 long-cadence intervals. A total of 198709 targets observed by Kepler were searched for evidence of transiting planets in the final Q1-Q17 pipeline run (see Table1). The results of past Kepler Mission transiting planet searches have been presented in Tenenbaum et al. 2012 (Cat. J/ApJS/199/24) for Quarter 1 through Quarter 3 (i.e., Q1-Q3), Tenenbaum et al. 2013ApJS..206....5T for Q1-Q12, Tenenbaum et al. 2014ApJS..211....6T for Q1-Q16, and Seader et al. 2015 (Cat. J/ApJS/217/18) for Q1-Q17. We now present results of the final Kepler transiting planet search encompassing the complete 17-quarter primary mission. The data release for the final Q1-Q17 pipeline processing is referred to as Data Release 25 (DR25). (3 data files).

  2. Gravitational lensing in a cold dark matter universe

    Science.gov (United States)

    Narayan, Ramesh; White, Simon D. M.

    1988-01-01

    Gravitational lensing due to mass condensations in a biased cold dark matter (CDM) universe is investigated using the Press-Schechter (1974) theory with density fluctuation amplitudes taken from previous N-body work. Under the critical assumption that CDM haloes have small core radii, a distribution of image angular separations for high-z lensed quasars with a peak at about 1 arcsec and a half-width of a factor of about 10. Allowing for selection effects at small angular separations, this is in good agreement with the observed separations. The estimated frequency of lensing is somewhat lower than that observed, but the discrepancy can be removed by invoking amplification bias and by making a small upward adjustment to the density fluctuation amplitudes assumed in the CDM model.

  3. Observations of Cluster Substructure using Weakly Lensed Sextupole Moments

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, John

    2003-08-01

    Since dark matter clusters and groups may have substructure, we have examined the sextupole content of Hubble images looking for a curvature signature in background galaxies that would arise from galaxy-galaxy lensing. We describe techniques for extracting and analyzing sextupole and higher weakly lensed moments. Indications of substructure, via spatial clumping of curved background galaxies, were observed in the image of CL0024 and then surprisingly in both Hubble deep fields. We estimate the dark cluster masses in the deep field. Alternatives to a lensing hypothesis appear improbable, but better statistics will be required to exclude them conclusively. Observation of sextupole moments would then provide a means to measure dark matter structure on smaller length scales than heretofore.

  4. Improvements to the Root Finding Algorithm in VBBinaryLensing

    Science.gov (United States)

    Heintz, Tyler; Hoag, Ava; Bozza, Valerio; Oberst, Thomas

    2018-01-01

    VBBinaryLensing is the leading code for fitting magnification maps to microlensing events by binary lenses, most especially for exoplanet discoveries. The majority of the code’s runtime is devoted to finding roots of a fifth order complex polynomial arising from the binary lens equation. This is currently accomplished via the ZROOTS subroutine, which employs Laguerre’s method. Skowron and Gould’s (2012) algorithm, which employs a combination of Laguerre’s and Newton’s methods, presents the possibility of faster runtimes. We introduce a C++ translation of Skowron and Gould’s algorithm and test it as a replacement for ZROOTS in VBBinaryLensing. We find that this new implementation both reduces the time spent finding roots and makes the code more robust in extreme regimes.

  5. Strong lensing of gravitational waves as seen by LISA.

    Science.gov (United States)

    Sereno, M; Sesana, A; Bleuler, A; Jetzer, Ph; Volonteri, M; Begelman, M C

    2010-12-17

    We discuss strong gravitational lensing of gravitational waves from the merging of massive black hole binaries in the context of the LISA mission. Detection of multiple events would provide invaluable information on competing theories of gravity, evolution and formation of structures and, possibly, constraints on H0 and other cosmological parameters. Most of the optical depth for lensing is provided by intervening massive galactic halos, for which wave optics effects are negligible. Probabilities to observe multiple events are sizable for a broad range of formation histories. For the most optimistic models, up to ≲ 4 multiple events with a signal to noise ratio ≳ 8 are expected in a 5-year mission. Chances are significant even for conservative models with either light (≲ 60%) or heavy (≲ 40%) seeds. Because of lensing amplification, some intrinsically too faint signals are brought over threshold (≲ 2 per year).

  6. Feedback as the source of imperfection in lossy perfect lenses

    Science.gov (United States)

    Rosenblatt, Gilad; Bartal, Guy; Orenstein, Meir

    2016-02-01

    The major barrier to realizing a perfect lens with left-handed materials is perceived to be their intrinsic loss. Here we show that only specific designs of perfect lenses are limited by loss—those in which material loss is translated to internal feedback. The asymptotically uniform transmission required for perfect lensing is hindered by such feedback, which generates resonances that lead to a spatial cutoff in the lens transmission. Moreover, uniform transmission and its resonant deterioration stem from completely separate classes of modal excitations. A perfect lens made of lossy left-handed materials is therefore not forbidden in principle. Pursuing perfect lens designs that avoid internal feedback offers a path towards realization of practical perfect lenses.

  7. Computerized calculation scheme for toric intraocular lenses.

    Science.gov (United States)

    Langenbucher, Achim; Seitz, Berthold

    2004-06-01

    While a number of intraocular lens (IOL) power prediction formulae are well established for determination of spherical lenses, no common strategy has been published for the computation of toric IOLs. The purpose of this study is to describe a paraxial computing scheme for tracing an axial pencil of rays through the 'optical system eye' containing astigmatic refractive surfaces with their axes at random. The capabilities of this computing scheme are demonstrated with clinical examples. Based on a schematic model eye with spherocylindric surfaces, we use two alternative notations for description of vergences or prescriptions: (1) standard notation (refraction in both cardinal meridians and axis), and (2) component notation (spherical equivalent and cylindric component in 0 degrees and 45 degrees. Refractive surfaces are added to the vergence in component notation, whereas the transformation of the vergence through media is performed in the standard notation for both cardinal meridians. For calculation of the toric lens implant, a pencil of rays is traced through the spectacle and the cornea to the estimated lens position as well as backwards from the retina to the estimated lens position. For calculation of residual spectacle refraction, a pencil of rays is traced backwards from the retina through the toric lens implant and the cornea to the spectacle plane. In example 1 we calculate a 'thin toric lens' for compensation of a corneal astigmatism to achieve a spherical target refraction. In example 2 we compute a 'thick toric lens', which has to compensate for an oblique corneal astigmatism and rotate the spectacle cylinder to the against the rule position to enhance near vision. In example 3 we estimate the residual refraction at the corneal plane after implantation of a thick toric lens, when the cylinder of the lens implant is compensating the corneal cylinder in part and the axis of implantation is not fully aligned with the axis of the corneal astigmatism. This

  8. Daily disposable contact lenses versus spectacles in teenagers.

    Science.gov (United States)

    Plowright, Andrew J; Maldonado-Codina, Carole; Howarth, Gillian F; Kern, Jami; Morgan, Philip B

    2015-01-01

    To compare clinical and subjective quality-of-life (QoL) data for teenagers wearing daily disposable contact lenses or spectacles. This open-label study randomized subjects (aged 13 to 19 years) with no previous contact lens wear experience to nelfilcon A (DAILIES AquaComfort Plus) contact lenses or spectacles for 6 months. A full clinical workup, as well as subjective QoL measures using the Pediatric Refractive Error Profile and Quality of Life Impact of Refractive Correction questionnaires, was conducted at baseline and at week 4 and months 3 and 6, with an additional study visit at week 2 for subjects randomized to wear contact lenses. A total of 110 teenagers were enrolled in the study; 13 discontinued before study completion, 10 (17.5%) from the contact lens group and 3 (5.7%) from the spectacle group (p = 0.04). Visual acuity was good for both groups at all study visits. Biomicroscopy assessments were similar at baseline for both groups. Significant differences in Pediatric Refractive Error Profile responses were noted between vision correction groups across visits for appearance (p teenagers had a more positive attitude toward comfort, vision, and safety with contact lenses. No serious adverse events were reported during the study. The daily disposable lenses used in this study are suitable for vision correction for teenagers, offering improvements in QoL measures during the first month of wear, including appearance, satisfaction, activities, and peer perceptions, without negatively impacting vision or eye health. Teenagers were able to handle contact lenses with the same amount of confidence as spectacles.

  9. Strong Lensing Science Results from the Hyper Suprime-Cam Survey

    Science.gov (United States)

    Wong, Kenneth; HSC SSP Strong Lens Working Group

    2018-01-01

    Strong gravitational lenses are valuable objects for studying galaxy structure and cosmology. Lensing is a unique probe of the dark matter structure of galaxies, groups, and clusters, as well as an independent tool for constraining cosmological parameters. Lensing also magnifies the background source population, allowing for detailed studies of their properties at high resolution. However, strong lenses are rare and difficult to find, requiring deep wide-area high-resolution imaging surveys. With data from the ongoing Hyper Suprime-Cam (HSC) Subaru Strategic Program, we have discovered over 100 new strong lenses at the galaxy and group scale to expand the sample of lensing systems, particularly at redshifts z > 0.5, where there have previously been relatively few known lenses. We present a summary of the latest strong lensing science results from the HSC survey data taken through the S17A semester.

  10. 21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

    Science.gov (United States)

    2010-04-01

    ... frequency of eye injuries resulting from the shattering of ordinary crown glass lenses indicates that the... multifocal, bioconcave, myodisc and minus lenticular, custom laminate and cemented assembly lenses shall be...

  11. Shadows and strong gravitational lensing: a brief review

    Science.gov (United States)

    Cunha, Pedro V. P.; Herdeiro, Carlos A. R.

    2018-04-01

    For ultra compact objects, light rings and fundamental photon orbits (FPOs) play a pivotal role in the theoretical analysis of strong gravitational lensing effects, and of BH shadows in particular. In this short review, specific models are considered to illustrate how FPOs can be useful in order to understand some non-trivial gravitational lensing effects. This paper aims at briefly overviewing the theoretical foundations of these effects, touching also some of the related phenomenology, both in general relativity and alternative theories of gravity, hopefully providing some intuition and new insights for the underlying physics, which might be critical when testing the Kerr black hole hypothesis.

  12. Application and System Design of Elastomer Based Optofluidic Lenses

    Science.gov (United States)

    Savidis, Nickolaos

    Adaptive optic technology has revolutionized real time correction of wavefront aberrations. Optofluidic based applied optic devices have offered an opportunity to produce flexible refractive lenses in the correction of wavefronts. Fluidic lenses have superiority relative to their solid lens counterparts in their capabilities of producing tunable optical systems, that when synchronized, can produce real time variable systems with no moving parts. We have developed optofluidic fluidic lenses for applications of applied optical devices, as well as ophthalmic optic devices. The first half of this dissertation discusses the production of fluidic lenses as optical devices. In addition, the design and testing of various fluidic systems made with these components are evaluated. We begin with the creation of spherical or defocus singlet fluidic lenses. We then produced zoom optical systems with no moving parts by synchronizing combinations of these fluidic spherical lenses. The variable power zoom system incorporates two singlet fluidic lenses that are synchronized. The coupled device has no moving parts and has produced a magnification range of 0.1 x to 10 x or a 20 x magnification range. The chapter after fluidic zoom technology focuses on producing achromatic lens designs. We offer an analysis of a hybrid diffractive and refractive achromat that offers discrete achromatized variable focal lengths. In addition, we offer a design of a fully optofluidic based achromatic lens. By synchronizing the two membrane surfaces of the fluidic achromat we develop a design for a fluidic achromatic lens. The second half of this dissertation discusses the production of optofluidic technology in ophthalmic applications. We begin with an introduction to an optofluidic phoropter system. A fluidic phoropter is designed through the combination of a defocus lens with two cylindrical fluidic lenses that are orientated 45° relative to each other. Here we discuss the designs of the fluidic

  13. Gravitational Lensing in the metric theory proposed by Sobouti

    Science.gov (United States)

    Bernal, Tula; Mendoza, Sergio

    2008-12-01

    Recently, Y. Sobouti (2007) has provided a metric theory f(R) that can account for certain dynamical anomalies observed in spiral galaxies. Mendoza & Rosas-Guevara (2007) have shown that in this theory there is an extra-bending as compared to standard general relativity. In the present work we have developed in more specific detail this additional lensing effect and we have made evaluations of the α parameter used in the model adjusting the theory to observations in X-rays of 13 clusters of galaxies with gravitational lensing ([6]).

  14. Probing dark energy with lensing magnification in photometric surveys.

    Science.gov (United States)

    Schneider, Michael D

    2014-02-14

    I present an estimator for the angular cross correlation of two tracers of the cosmological large-scale structure that utilizes redshift information to isolate separate physical contributions. The estimator is derived by solving the Limber equation for a reweighting of the foreground tracer that nulls either clustering or lensing contributions to the cross correlation function. Applied to future photometric surveys, the estimator can enhance the measurement of gravitational lensing magnification effects to provide a competitive independent constraint on the dark energy equation of state.

  15. Predicting How Close Near-Earth Asteroids Will Come to Earth in the Next Five Years Using Only Kepler's Algorithm

    National Research Council Canada - National Science Library

    Wright, Melissa

    1998-01-01

    .... The goal of th is investigation was to see if using only Kepler's algorithm, which ignores the gravitational pull of other planets, our moon, and Jupiter, was sufficient to predict close encounters with Earth...

  16. Near Mean-motion Resonances in the System Observed by Kepler: Affected by Mass Accretion and Type I Migration

    Science.gov (United States)

    Wang, Su; Ji, Jianghui

    2017-12-01

    The Kepler mission has released over 4496 planetary candidates, among which 3483 planets have been confirmed as of 2017 April. The statistical results of the planets show that there are two peaks around 1.5 and 2.0 in the distribution of orbital period ratios. The observations indicate that plenty of planet pairs could have first been captured into mean-motion resonances (MMRs) in planetary formation. Subsequently, these planets depart from exact resonant locations to be near-MMR configurations. Through type I migration, two low-mass planets have a tendency to be trapped in first-order MMRs (2:1 or 3:2 MMRs); however, two scenarios of mass accretion of planets and potential outward migration play important roles in reshaping their final orbital configurations. Under the scenario of mass accretion, the planet pairs can cross 2:1 MMRs and then enter into 3:2 MMRs, especially for the inner pairs. With such a formation scenario, the possibility that two planets are locked into 3:2 MMRs can increase if they are formed in a flat disk. Moreover, the outward migration can make planets have a high likelihood to be trapped into 3:2 MMRs. We perform additional runs to investigate the mass relationship for those planets in three-planet systems, and we show that two peaks near 1.5 and 2.0 for the period ratios of two planets can be easily reproduced through our formation scenario. We further show that the systems in chain resonances (e.g., 4:2:1, 3:2:1, 6:3:2, and 9:6:4 MMRs), have been observed in our simulations. This mechanism can be applicable to understand the formation of systems of Kepler-48, Kepler-53, Kepler-100, Kepler-192, Kepler-297, Kepler-399, and Kepler-450.

  17. THE HUNT FOR EXOMOONS WITH KEPLER (HEK). III. THE FIRST SEARCH FOR AN EXOMOON AROUND A HABITABLE-ZONE PLANET

    Energy Technology Data Exchange (ETDEWEB)

    Kipping, D. M. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Forgan, D. [Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Hartman, J.; Bakos, G. Á. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States); Nesvorný, D. [Department of Space Studies, Southwest Research Institute, Boulder, CO 80302 (United States); Schmitt, A.; Buchhave, L., E-mail: dkipping@cfa.harvard.edu [Niels Bohr Institute, Copenhagen University (Denmark)

    2013-11-10

    Kepler-22b is the first transiting planet to have been detected in the habitable zone of its host star. At 2.4 R{sub ⊕}, Kepler-22b is too large to be considered an Earth analog, but should the planet host a moon large enough to maintain an atmosphere, then the Kepler-22 system may yet possess a telluric world. Aside from being within the habitable zone, the target is attractive due to the availability of previously measured precise radial velocities and low intrinsic photometric noise, which has also enabled asteroseismology studies of the star. For these reasons, Kepler-22b was selected as a target-of-opportunity by the 'Hunt for Exomoons with Kepler' (HEK) project. In this work, we conduct a photodynamical search for an exomoon around Kepler-22b leveraging the transits, radial velocities, and asteroseismology plus several new tools developed by the HEK project to improve exomoon searches. We find no evidence for an exomoon around the planet and exclude moons of mass M{sub S} > 0.5 M{sub ⊕} to 95% confidence. By signal injection and blind retrieval, we demonstrate that an Earth-like moon is easily detected for this planet even when the time-correlated noise of the data set is taken into account. We provide updated parameters for the planet Kepler-22b, including a revised mass of M{sub P} < 53 M{sub ⊕} to 95% confidence and an eccentricity of 0.13{sub -0.13}{sup +0.36} by exploiting Single-body Asterodensity Profiling. Finally, we show that Kepler-22b has a >95% probability of being within the empirical habitable zone but a <5% probability of being within the conservative habitable zone.

  18. Cross-correlation of gravitational lensing from DES Science Verification data with SPT and Planck lensing

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, D.; Omori, Y.; Benoit-Lévy, A.; Cawthon, R.; Chang, C.; Larsen, P.; Amara, A.; Bacon, D.; Crawford, T. M.; Dodelson, S.; Fosalba, P.; Giannantonio, T.; Holder, G.; Jain, B.; Kacprzak, T.; Lahav, O.; MacCrann, N.; Nicola, A.; Refregier, A.; Sheldon, E.; Story, K. T.; Troxel, M. A.; Vieira, J. D.; Vikram, V.; Zuntz, J.; Abbott, T. M. C.; Abdalla, F. B.; Becker, M. R.; Benson, B. A.; Bernstein, G. M.; Bernstein, R. A.; Bleem, L. E.; Bonnett, C.; Bridle, S. L.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carlstrom, J. E.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Crocce, M.; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Frieman, J.; Gerdes, D. W.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D. J.; Jarvis, M.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Lima, M.; March, M.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Nichol, R. C.; Ogando, R.; Plazas, A. A.; Reichardt, C. L.; Roodman, A.; Rozo, E.; Rykoff, E. S.; Sako, M.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Simard, G.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Wechsler, R. H.; Weller, J.

    2016-03-10

    We measure the cross-correlation between weak lensing of galaxy images and of the cosmic microwave background (CMB). The effects of gravitational lensing on different sources will be correlated if the lensing is caused by the same mass fluctuations. We use galaxy shape measurements from 139 deg(2) of the Dark Energy Survey (DES) Science Verification data and overlapping CMB lensing from the South Pole Telescope (SPT) and Planck. The DES source galaxies have a median redshift of z(med) similar to 0.7, while the CMB lensing kernel is broad and peaks at z similar to 2. The resulting cross-correlation is maximally sensitive to mass fluctuations at z similar to 0.44. Assuming the Planck 2015 best-fitting cosmology, the amplitude of the DESxSPT cross-power is found to be A(SPT) = 0.88 +/- 0.30 and that from DESxPlanck to be A(Planck) = 0.86 +/- 0.39, where A = 1 corresponds to the theoretical prediction. These are consistent with the expected signal and correspond to significances of 2.9 sigma and 2.2 sigma, respectively. We demonstrate that our results are robust to a number of important systematic effects including the shear measurement method, estimator choice, photo-z uncertainty and CMB lensing systematics. We calculate a value of A = 1.08 +/- 0.36 for DESxSPT when we correct the observations with a simple intrinsic alignment model. With three measurements of this cross-correlation now existing in the literature, there is not yet reliable evidence for any deviation from the expected LCDM level of cross-correlation. We provide forecasts for the expected signal-to-noise ratio of the combination of the five-year DES survey and SPT-3G.

  19. Cellular proliferation and regeneration following tissue damage. Progress report. [X radiation; rabbit lenses

    Energy Technology Data Exchange (ETDEWEB)

    Harding, C.V.

    1977-01-01

    Studies were conducted on the following research projects: effects of x radiation on rabbit lenses; DNA synthesis and mitosis in cultured lenses; serum dependency and actinomycin D sensitivity; changes in ultrastructure; injury-induced growth of vascular endothelium; corneal neovascularization following injury; and human cataractous lenses. (HLW)

  20. High Quality Liquid Crystal Tunable Lenses and Optimization with Floating Electrodes

    Science.gov (United States)

    Li, Liwei

    2013-01-01

    In addition to the display application, Liquid Crystals (LC) can be very useful in other applications such as beam steering, tunable lenses, etc. Electro-optical LC tunable lenses have been considered as an alternative to conventional glass lenses because of their ability to change their focal length with the application of a control voltage, as…