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Jason W. Barnes

Bio: Jason W. Barnes is an academic researcher from University of Idaho. The author has contributed to research in topics: Titan (rocket family) & Planet. The author has an hindex of 48, co-authored 232 publications receiving 11237 citations. Previous affiliations of Jason W. Barnes include California Institute of Technology & University of Arizona.


Papers
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Journal ArticleDOI
19 Feb 2010-Science
TL;DR: The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars, which is the region where planetary temperatures are suitable for water to exist on a planet's surface.
Abstract: 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 monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 days were discovered. The density of the Neptune-sized Kepler-4b is similar to that of Neptune and GJ 436b, even though the irradiation level is 800,000 times higher. Kepler-7b 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.

3,663 citations

Journal ArticleDOI
TL;DR: For hydrogen-helium-rich planets, the authors in this article couple planetary evolution to stellar irradiation over a wide range of orbital separations (0.02-10 AU) through a nongray radiative-convective equilibrium atmosphere model.
Abstract: Toaidinthephysicalinterpretationofplanetaryradii constrainedthroughobservationsoftransitingplanets,oreventuallydirectdetections,wecomputemodelradiiofpurehydrogen-helium,water,rock,andironplanets,alongwithvarious mixtures. Masses ranging from 0.01 Earth masses to 10 Jupiter masses at orbital distances of 0.02–10 AU are considered. For hydrogen-helium rich planets, our models are the first to couple planetary evolution to stellar irradiation over a wide range of orbital separations (0.02–10 AU) through a nongray radiative-convective equilibrium atmosphere model. Stellar irradiation retards the contraction of giant planets, but its effect is not a simple function of theirradiationlevel:aplanetat1AUcontractsasslowlyasaplanetat0.1AU.WeconfirmtheassertionofGuillotthat very old giant planets under modest stellar irradiation (like that received by Jupiter and Saturn) develop isothermal atmospheric radiative zones once the planet’s intrinsic flux drops to a small fraction of the incident flux. For hydrogenhelium planets, we consider cores up to 90% of the total planet mass, comparable to those of Uranus and Neptune. If ‘‘hot Neptunes’’ have maintained their original masses and are not remnants of more massive planets, radii of � 0.30– 0.45RJ areexpected.Waterplanetsare � 40%–50%largerthanrockyplanets,independentofmass.Finally,weprovide tables of planetary radii at various ages and compositions, and for ice-rock-iron planets we fit our results to analytic functions, which will allow for quick composition estimates, given masses and radii, or mass estimates, given only planetary radii. These results will assist in the interpretation of observations for both the current transiting planet surveys as well as upcoming space missions, including COROT and Kepler.

995 citations

Journal ArticleDOI
31 Jul 2008-Nature
TL;DR: Infrared spectroscopic data obtained by the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft strongly indicate that ethane, probably in liquid solution with methane, nitrogen and other low-molecular-mass hydrocarbons, is contained within Titan’s Ontario Lacus.
Abstract: Saturn's moon Titan was once thought to have global oceans of light hydrocarbons on its surface, but the Cassini spacecraft's 40 close flybys of Titan have shown that no such oceans exist. Yet there are surface features similar to terrestrial lakes and seas. Infrared spectroscopic data from Cassini's 38th flyby reveal a possible explanation. The spectra and physical appearance of Ontario Lacus, a lake-like structure near Titan's south pole, support the idea that it is filled with liquid ethane, probably in solution with methane, nitrogen and other hydrocarbons. Titan was once hypothesized to have global oceans of light hydrocarbons, but it has become clear that none exist. However there are features similar to terrestrial lakes and seas. This paper reports infrared spectroscopic data that strongly indicate that ethane, probably in liquid solution with methane, nitrogen, and other low-molecular-weight hydrocarbons, is contained within Titan's Ontario Lacus. Titan was once thought to have global oceans of light hydrocarbons on its surface1,2,3,4,5, but after 40 close flybys of Titan by the Cassini spacecraft, it has become clear that no such oceans exist6. There are, however, features similar to terrestrial lakes and seas7, and widespread evidence for fluvial erosion8,9, presumably driven by precipitation of liquid methane from Titan’s dense, nitrogen-dominated atmosphere10. Here we report infrared spectroscopic data, obtained by the Visual and Infrared Mapping Spectrometer11 (VIMS) on board the Cassini spacecraft, that strongly indicate that ethane, probably in liquid solution with methane, nitrogen and other low-molecular-mass hydrocarbons, is contained within Titan’s Ontario Lacus.

262 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigate the long-term dynamical stability of hypothetical moons orbiting extrasolar giant planets and derive an upper mass limit for those satellites that might have survived to the present day.
Abstract: We investigate the long-term dynamical stability of hypothetical moons orbiting extrasolar giant planets. Stellar tides brake a planet's rotation and, together with tidal migration, act to remove satellites; this process limits the lifetimes of larger moons in extrasolar planetary systems. Because more massive satellites are removed more quickly than less massive ones, we are able to derive an upper mass limit for those satellites that might have survived to the present day. For example, we estimate that no primordial satellites with masses greater than 7 × 10-7 M⊕ (~70 km radius for ρ = 3 g cm-3) could have survived around the transiting planet HD 209458b for the age of the system. No meaningful mass limits can be placed on moons orbiting Jovian planets more than ~0.6 AU from their parent stars. Earthlike moons of Jovian planets could exist for 5 Gyr in systems where the stellar mass is greater than 0.15 M☉. Transits show the most promise for the discovery of extrasolar moons—we discuss prospects for satellite detection via transits using space-based photometric surveys and the limits on the planetary tidal dissipation factor Qp that a discovery would imply.

227 citations


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Journal ArticleDOI
TL;DR: Modules for Experiments in Stellar Astrophysics (MESA) as discussed by the authors can now simultaneously evolve an interacting pair of differentially rotating stars undergoing transfer and loss of mass and angular momentum, greatly enhancing the prior ability to model binary evolution.
Abstract: We substantially update the capabilities of the open-source software instrument Modules for Experiments in Stellar Astrophysics (MESA). MESA can now simultaneously evolve an interacting pair of differentially rotating stars undergoing transfer and loss of mass and angular momentum, greatly enhancing the prior ability to model binary evolution. New MESA capabilities in fully coupled calculation of nuclear networks with hundreds of isotopes now allow MESA to accurately simulate advanced burning stages needed to construct supernova progenitor models. Implicit hydrodynamics with shocks can now be treated with MESA, enabling modeling of the entire massive star lifecycle, from pre-main sequence evolution to the onset of core collapse and nucleosynthesis from the resulting explosion. Coupling of the GYRE non-adiabatic pulsation instrument with MESA allows for new explorations of the instability strips for massive stars while also accelerating the astrophysical use of asteroseismology data. We improve treatment of mass accretion, giving more accurate and robust near-surface profiles. A new MESA capability to calculate weak reaction rates "on-the-fly" from input nuclear data allows better simulation of accretion induced collapse of massive white dwarfs and the fate of some massive stars. We discuss the ongoing challenge of chemical diffusion in the strongly coupled plasma regime, and exhibit improvements in MESA that now allow for the simulation of radiative levitation of heavy elements in hot stars. We close by noting that the MESA software infrastructure provides bit-for-bit consistency for all results across all the supported platforms, a profound enabling capability for accelerating MESA's development.

2,166 citations

Journal ArticleDOI
TL;DR: The K2 mission as discussed by the authors uses an innovative way of operating the Kepler spacecraft to observe target fields along the ecliptic for the next 2-3 years, with an estimated photometric precision near 400 ppm in a single 30 minute observation.
Abstract: The K2 mission will make use of the Kepler spacecraft and its assets to expand upon Kepler's groundbreaking discoveries in the fields of exoplanets and astrophysics through new and exciting observations. K2 will use an innovative way of operating the spacecraft to observe target fields along the ecliptic for the next 2-3 years. Early science commissioning observations have shown an estimated photometric precision near 400 ppm in a single 30 minute observation, and a 6-hr photometric precision of 80 ppm (both at V = 12). The K2 mission offers long-term, simultaneous optical observation of thousands of objects at a precision far better than is achievable from ground-based telescopes. Ecliptic fields will be observed for approximately 75 days enabling a unique exoplanet survey which fills the gaps in duration and sensitivity between the Kepler and TESS missions, and offers pre-launch exoplanet target identification for JWST transit spectroscopy. Astrophysics observations with K2 will include studies of young open clusters, bright stars, galaxies, supernovae, and asteroseismology.

1,672 citations

Journal ArticleDOI
TL;DR: Modules for Experiments in Stellar Astrophysics (MESA) as discussed by the authors can now simultaneously evolve an interacting pair of differentially rotating stars undergoing transfer and loss of mass and angular momentum, greatly enhancing the prior ability to model binary evolution.
Abstract: We substantially update the capabilities of the open-source software instrument Modules for Experiments in Stellar Astrophysics (MESA). MESA can now simultaneously evolve an interacting pair of differentially rotating stars undergoing transfer and loss of mass and angular momentum, greatly enhancing the prior ability to model binary evolution. New MESA capabilities in fully coupled calculation of nuclear networks with hundreds of isotopes now allow MESA to accurately simulate advanced burning stages needed to construct supernova progenitor models. Implicit hydrodynamics with shocks can now be treated with MESA, enabling modeling of the entire massive star lifecycle, from pre-main sequence evolution to the onset of core collapse and nucleosynthesis from the resulting explosion. Coupling of the GYRE non-adiabatic pulsation instrument with MESA allows for new explorations of the instability strips for massive stars while also accelerating the astrophysical use of asteroseismology data. We improve treatment of mass accretion, giving more accurate and robust near-surface profiles. A new MESA capability to calculate weak reaction rates "on-the-fly" from input nuclear data allows better simulation of accretion induced collapse of massive white dwarfs and the fate of some massive stars. We discuss the ongoing challenge of chemical diffusion in the strongly coupled plasma regime, and exhibit improvements in MESA that now allow for the simulation of radiative levitation of heavy elements in hot stars. We close by noting that the MESA software infrastructure provides bit-for-bit consistency for all results across all the supported platforms, a profound enabling capability for accelerating MESA's development.

1,401 citations

Journal ArticleDOI
Steven R. Majewski1, Ricardo P. Schiavon2, Peter M. Frinchaboy3, Carlos Allende Prieto4, Carlos Allende Prieto5, Robert H. Barkhouser6, Dmitry Bizyaev7, Dmitry Bizyaev8, Basil Blank, Sophia Brunner1, Adam Burton1, Ricardo Carrera4, Ricardo Carrera5, S. Drew Chojnowski8, S. Drew Chojnowski1, Katia Cunha9, Courtney R. Epstein10, Greg Fitzgerald, Ana E. García Pérez5, Ana E. García Pérez1, Fred Hearty1, Fred Hearty11, Chuck Henderson, Jon A. Holtzman8, Jennifer A. Johnson10, Charles R. Lam1, James E. Lawler12, Paul Maseman9, Szabolcs Mészáros5, Szabolcs Mészáros13, Szabolcs Mészáros4, Matthew J. Nelson1, Duy Coung Nguyen14, David L. Nidever1, David L. Nidever15, Marc H. Pinsonneault10, Matthew Shetrone16, Stephen A. Smee6, Verne V. Smith9, T. Stolberg, Michael F. Skrutskie1, E. Walker1, John C. Wilson1, Gail Zasowski1, Gail Zasowski6, Friedrich Anders17, Sarbani Basu18, Stephane Beland19, Michael R. Blanton20, Jo Bovy21, Jo Bovy14, Joel R. Brownstein22, Joleen K. Carlberg23, Joleen K. Carlberg1, William J. Chaplin24, William J. Chaplin25, Cristina Chiappini17, Daniel J. Eisenstein26, Yvonne Elsworth25, Diane Feuillet8, Scott W. Fleming27, Scott W. Fleming28, Jessica Galbraith-Frew22, Rafael A. García29, D. Anibal García-Hernández5, D. Anibal García-Hernández4, Bruce Gillespie6, Léo Girardi30, James E. Gunn21, Sten Hasselquist1, Sten Hasselquist8, Michael R. Hayden8, Saskia Hekker31, Saskia Hekker24, Inese I. Ivans22, Karen Kinemuchi8, Mark A. Klaene8, Suvrath Mahadevan11, Savita Mathur32, Benoit Mosser33, Demitri Muna10, Jeffrey A. Munn, Robert C. Nichol, Robert W. O'Connell1, John K. Parejko18, Annie C. Robin34, H. J. Rocha-Pinto35, M. Schultheis36, Aldo Serenelli5, Neville Shane1, Victor Silva Aguirre24, Jennifer Sobeck1, Benjamin A. Thompson3, Nicholas W. Troup1, David H. Weinberg10, Olga Zamora4, Olga Zamora5 
TL;DR: In this article, the Hungarian National Research, Development and Innovation Office (K-119517) and Hungarian National Science Foundation (KNFI) have proposed a method to detect the presence of asteroids in Earth's magnetic field.
Abstract: National Science Foundation [AST-1109178, AST-1616636]; Gemini Observatory; Spanish Ministry of Economy and Competitiveness [AYA-2011-27754]; NASA [NNX12AE17G]; Hungarian Academy of Sciences; Hungarian NKFI of the Hungarian National Research, Development and Innovation Office [K-119517]; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy Office of Science

1,193 citations

Journal ArticleDOI
TL;DR: The 10th public data release (DR10) from the Sloan Digital Sky Survey (SDSS-III) was released in 2013 as mentioned in this paper, which includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopy data from Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July.
Abstract: The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R ~ 22,500 300 fiber spectrograph covering 1.514-1.696 μm. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included. DR10 also roughly doubles the number of BOSS spectra over those included in the Ninth Data Release. DR10 includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxy spectra, 182,009 quasar spectra, and 159,327 stellar spectra selected over 6373.2 deg2.

1,188 citations