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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
A Super-Earth And Two Neptunes Orbiting The Nearby Sun-Like Star 61 Virginis, Steve Vogt, Robert A. Wittenmyer, R. Paul Butler, Simon O'Toole, Gregory W. Henry, Eugenio J. Rivera, Stefano Meschiari, Gregory Laughlin, Chris G. Tinney, Hugh R. A. Jones, Jeremy Bailey, Brad D. Carter, Konstantin Batygin
A Super-Earth And Two Neptunes Orbiting The Nearby Sun-Like Star 61 Virginis, Steve Vogt, Robert A. Wittenmyer, R. Paul Butler, Simon O'Toole, Gregory W. Henry, Eugenio J. Rivera, Stefano Meschiari, Gregory Laughlin, Chris G. Tinney, Hugh R. A. Jones, Jeremy Bailey, Brad D. Carter, Konstantin Batygin
Information Systems and Engineering Management Research Publications
We present precision radial velocity data that reveal a multiple exoplanet system orbiting the bright nearby G5V star 61 Virginis. Our 4.6 years of combined Keck/HIRES and Anglo-Australian Telescope precision radial velocities indicate the hitherto unknown presence of at least three planets orbiting this well-studied star. These planets are all on low-eccentricity orbits with periods of 4.2, 38.0, and 124.0 days, and projected masses (Msin i) of 5.1, 18.2, and 24.0 M⊕, respectively. Test integrations of systems consistent with the radial velocity data suggest that the configuration is dynamically stable. Depending on the effectiveness of tidal dissipation within the inner …
A Super-Earth Orbiting The Nearby Sun-Like Star Hd 1461, Eugenio J. Rivera, R. Paul Butler, Steve Vogt, Gregory Laughlin, Gregory W. Henry, Stefano Meschiari
A Super-Earth Orbiting The Nearby Sun-Like Star Hd 1461, Eugenio J. Rivera, R. Paul Butler, Steve Vogt, Gregory Laughlin, Gregory W. Henry, Stefano Meschiari
Information Systems and Engineering Management Research Publications
We present precision radial velocity (RV) data that reveal a Super-Earth mass planet and two probable additional planets orbiting the bright nearby G0V star HD 1461. Our 12.8 years of Keck High Resolution Echelle Spectrometer precision RVs indicate the presence of a 7.4 M⊕ planet on a 5.77 day orbit. The data also suggest, but cannot yet confirm, the presence of outer planets on low-eccentricity orbits with periods of 446.1 and 5017 days, and projected masses (Msin i) of 27.9 and 87.1 M⊕, respectively. Test integrations of systems consistent with the RV data suggest that the configuration is dynamically stable. …
Five Planets And An Independent Confirmation Of Hd 196885ab From Lick Observatory, Debra A. Fischer, Peter Driscoll, Howard Isaacson, Matthew J. Giguere, Geoffrey W. Marcy, Jeff A. Valenti, Jason T. Wright, Gregory W. Henry, John Asher Johnson, Andrew W. Howard, Kathryn M. G. Peek, Chris Mccarthy
Five Planets And An Independent Confirmation Of Hd 196885ab From Lick Observatory, Debra A. Fischer, Peter Driscoll, Howard Isaacson, Matthew J. Giguere, Geoffrey W. Marcy, Jeff A. Valenti, Jason T. Wright, Gregory W. Henry, John Asher Johnson, Andrew W. Howard, Kathryn M. G. Peek, Chris Mccarthy
Information Systems and Engineering Management Research Publications
We present time series Doppler data from Lick Observatory that reveal the presence of long-period planetary companions orbiting nearby stars. The typical eccentricity of these massive planets are greater than the mean eccentricity of known exoplanets. HD 30562b has Msin i = 1.29 MJup, with semimajor axis of 2.3 AU and eccentricity 0.76. The host star has a spectral type F8V and is metal rich. HD 86264b has Msin i = 7.0 MJup, arel = 2.86 AU, an eccentricity e = 0.7 and orbits a metal-rich, F7V star. HD 87883b has Msin i = 1.78 MJup, arel = 3.6 AU, …
The 8 Μm Phase Variation Of The Hot Saturn Hd 149026b, Heather Knutson, David Charbonneau, Nicolas B. Cowan, Jonathan J. Fortney, Adam P. Showman, Eric Agol, Gregory W. Henry
The 8 Μm Phase Variation Of The Hot Saturn Hd 149026b, Heather Knutson, David Charbonneau, Nicolas B. Cowan, Jonathan J. Fortney, Adam P. Showman, Eric Agol, Gregory W. Henry
Information Systems and Engineering Management Research Publications
We monitor the star HD 149026 and its Saturn-mass planet at 8.0 μm over slightly more than half an orbit using the Infrared Array Camera on the Spitzer Space Telescope. We find an increase of 0.0227% ± 0.0066% (3.4σ significance) in the combined planet–star flux during this interval. The minimum flux from the planet is 45% ± 19% of the maximum planet flux, corresponding to a difference in brightness temperature of 480 ± 140 K between the two hemispheres. We derive a new secondary eclipse depth of 0.0411% ± 0.0076% in this band, corresponding to a dayside brightness temperature of …
Two Exoplanets Discovered At Keck Observatory, Jeff A. Valenti, Debra A. Fischer, Geoffrey W. Marcy, John Asher Johnson, Gregory W. Henry, Jason T. Wright, Andrew W. Howard, Matthew J. Giguere, Howard Isaacson
Two Exoplanets Discovered At Keck Observatory, Jeff A. Valenti, Debra A. Fischer, Geoffrey W. Marcy, John Asher Johnson, Gregory W. Henry, Jason T. Wright, Andrew W. Howard, Matthew J. Giguere, Howard Isaacson
Information Systems and Engineering Management Research Publications
We present two exoplanets detected at Keck Observatory. HD 179079 is a G5 subgiant that hosts a hot Neptune planet with M sin i = 27.5 M⊕ in a 14.48 days, low-eccentricity orbit. The stellar reflex velocity induced by this planet has a semiamplitude of K = 6.6 m s−1. HD 73534 is a G5 subgiant with a Jupiter-like planet of M sin i = 1.1 MJup and K = 16 m s−1 in a nearly circular 4.85 yr orbit. Both stars are chromospherically inactive and metal-rich. We discuss a known, classical bias in measuring eccentricities for orbits with velocity …
Transit Spectrophotometry Of The Exoplanet Hd 189733b I. Searching For Water But Finding Haze With Hst Nicmos, David K. Sing, Jean-Michel Désert, Alain Lecavelier Des Etangs, Gilda E. Ballester, Alfred Vidal-Madjar, Vivien Parmentier, Guillaume Hébrard, Gregory W. Henry
Transit Spectrophotometry Of The Exoplanet Hd 189733b I. Searching For Water But Finding Haze With Hst Nicmos, David K. Sing, Jean-Michel Désert, Alain Lecavelier Des Etangs, Gilda E. Ballester, Alfred Vidal-Madjar, Vivien Parmentier, Guillaume Hébrard, Gregory W. Henry
Information Systems and Engineering Management Research Publications
We present Hubble Space Telescope near-infrared transit photometry of the nearby hot-Jupiter HD 189733b. The observations were taken with the NICMOS instrument during five transits, with three transits executed with a narrowband filter at 1.87 m and two performed with a narrowband filter at 1.66 m. Our observing strategy using narrowband filters is insensitive to the usual HST intra-orbit and orbit-to-orbit measurement of systematic errors, allowing us to accurately and robustly measure the near-IR wavelength dependance of the planetary radius. Our measurements fail to reproduce the previously claimed detection of an absorption signature of atmospheric H2O below …
A Third Giant Planet Orbiting Hip 14810, Jason T. Wright, Debra A. Fischer, Eric B. Ford, Dimitri Veras, Ji Wang, Gregory W. Henry, Geoffrey W. Marcy, Andrew W. Howard, John Asher Johnson
A Third Giant Planet Orbiting Hip 14810, Jason T. Wright, Debra A. Fischer, Eric B. Ford, Dimitri Veras, Ji Wang, Gregory W. Henry, Geoffrey W. Marcy, Andrew W. Howard, John Asher Johnson
Information Systems and Engineering Management Research Publications
We present new precision radial velocities and a three-planet Keplerian orbit fit for the V = 8.5, G5 V star HIP 14810. We began observing this star at Keck Observatory as part of the N2K Planet Search Project. Wright et al. announced the inner two planets to this system, and subsequent observations have revealed the outer planet and the proper orbital solution for the middle planet. The planets have minimum masses of 3.9, 1.3, and 0.6 MJup and orbital periods of 6.67, 147.7, and 952 day, respectively. We have numerically integrated the family of orbital solutions consistent with the data …
A Search For Multi-Planet Systems Using The Hobby–Eberly Telescope, Robert A. Wittenmyer, Michael Endl, William D. Cochran, Harold F. Levison, Gregory W. Henry
A Search For Multi-Planet Systems Using The Hobby–Eberly Telescope, Robert A. Wittenmyer, Michael Endl, William D. Cochran, Harold F. Levison, Gregory W. Henry
Information Systems and Engineering Management Research Publications
Extrasolar multiple-planet systems provide valuable opportunities for testing theories of planet formation and evolution. The architectures of the known multiple-planet systems demonstrate a fascinating level of diversity, which motivates the search for additional examples of such systems in order to better constrain their formation and dynamical histories. Here we describe a comprehensive investigation of 22 planetary systems in an effort to answer three questions: (1) are there additional planets? (2) where could additional planets reside in stable orbits? and (3) what limits can these observations place on such objects? We find no evidence for additional bodies in any of these …
The Nasa-Uc Eta-Earth Program. I. A Super-Earth Orbiting Hd 7924, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, Gregory W. Henry, Matthew J. Giguere, Howard Isaacson, Jeff A. Valenti, Jay Anderson, Nikolai Piskunov
The Nasa-Uc Eta-Earth Program. I. A Super-Earth Orbiting Hd 7924, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, Gregory W. Henry, Matthew J. Giguere, Howard Isaacson, Jeff A. Valenti, Jay Anderson, Nikolai Piskunov
Information Systems and Engineering Management Research Publications
We report the discovery of the first low-mass planet to emerge from the NASA-UC Eta-Earth Program, a super-Earth orbiting the K0 dwarf HD 7924. Keplerian modeling of precise Doppler radial velocities reveals a planet with minimum mass MPsin i = 9.26 M⊕ in a P = 5.398 d orbit. Based on Keck-HIRES measurements from 2001 to 2008, the planet is robustly detected with an estimated false alarm probability of less than 0.001. Photometric observations using the Automated Photometric Telescopes at Fairborn Observatory show that HD 7924 is photometrically constant over the radial velocity period to 0.19 mmag, supporting the existence …
The Transit Light Curve Project. X. A Christmas Transit Of Hd 17156b, Joshua N. Winn, Matthew J. Holman, Gregory W. Henry, Guillermo Torres, Debra A. Fischer, John Asher Johnson, Geoffrey W. Marcy, Avi Shporer, Tsevi Mazeh
The Transit Light Curve Project. X. A Christmas Transit Of Hd 17156b, Joshua N. Winn, Matthew J. Holman, Gregory W. Henry, Guillermo Torres, Debra A. Fischer, John Asher Johnson, Geoffrey W. Marcy, Avi Shporer, Tsevi Mazeh
Information Systems and Engineering Management Research Publications
Photometry is presented of the 2007 December 25 transit of HD 17156b, which has the longest orbital period and highest orbital eccentricity of all the known transiting exoplanets. New measurements of the stellar radial velocity are also presented. All the data are combined and integrated with stellar-evolutionary modeling to derive refined system parameters. The planet's mass and radius are found to be 3.212+0.069−0.082 MJup and 1.023+0.070−0.055 RJup. The corresponding stellar properties are 1.263+0.035−0.047 M☉ and 1.446+0.099−0.067 R☉. The planet is smaller by 1σ than a theoretical solar-composition gas giant with the same mass and equilibrium temperature, a possible indication of …
Discovery Of A Low-Mass Companion To The Solar-Type Star Tyc 2534-698-1, Stephen R. Kane, Suvrath Mahadevan, William D. Cochran, Rachel A. Street, Sivarani Thirupathi, Gregory W. Henry, Michael H. Williamson
Discovery Of A Low-Mass Companion To The Solar-Type Star Tyc 2534-698-1, Stephen R. Kane, Suvrath Mahadevan, William D. Cochran, Rachel A. Street, Sivarani Thirupathi, Gregory W. Henry, Michael H. Williamson
Information Systems and Engineering Management Research Publications
Brown dwarfs and low-mass stellar companions are interesting objects to study since they occupy the mass region between deuterium and hydrogen burning. We report here the serendipitous discovery of a low-mass companion in an eccentric orbit around a solar-type main-sequence star. The stellar primary, TYC 2534-698-1, is a G2V star that was monitored both spectroscopically and photometrically over the course of several months. Radial velocity observations indicate a minimum mass of 0.037 M☉ and an orbital period of ∼103 days for the companion. Photometry outside of the transit window shows the star to be stable to within ∼6 millimags. The …