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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
A High-Eccentricity Component In The Double-Planet System Around Hd 163607 And A Planet Around Hd 164509*, Matthew J. Giguere, Debra A. Fischer, Andrew W. Howard, John A. Johnson, Gregory W. Henry, Jason T. Wright, Geoffrey W. Marcy, Howard Isaacson, Fengji Hou, Julien Spronck
A High-Eccentricity Component In The Double-Planet System Around Hd 163607 And A Planet Around Hd 164509*, Matthew J. Giguere, Debra A. Fischer, Andrew W. Howard, John A. Johnson, Gregory W. Henry, Jason T. Wright, Geoffrey W. Marcy, Howard Isaacson, Fengji Hou, Julien Spronck
Information Systems and Engineering Management Research Publications
We report the detection of three new exoplanets from Keck Observatory. HD 163607 is a metal-rich G5IV star with two planets. The inner planet has an observed orbital period of 75.29 ± 0.02 days, a semi-amplitude of 51.1 ± 1.4 m s−1, an eccentricity of 0.73 ± 0.02, and a derived minimum mass of MPsin i = 0.77 ± 0.02 MJup. This is the largest eccentricity of any known planet in a multi-planet system. The argument of periastron passage is 78.7 ± 2fdg0; consequently, the planet's closest approach to its parent star is very near the line of sight, leading …
A Search For The Transit Of Hd 168443b: Improved Orbital Parameters And Photometry, Genady Pilyavsky, Suvrath Mahadevan, Stephen R. Kane, Andrew W. Howard, David R. Ciardi, Chris De Pree, Diana Dragomir, Debra A. Fischer, Gregory W. Henry, Eric L. N. Jensen, Gregory Laughlin
A Search For The Transit Of Hd 168443b: Improved Orbital Parameters And Photometry, Genady Pilyavsky, Suvrath Mahadevan, Stephen R. Kane, Andrew W. Howard, David R. Ciardi, Chris De Pree, Diana Dragomir, Debra A. Fischer, Gregory W. Henry, Eric L. N. Jensen, Gregory Laughlin
Information Systems and Engineering Management Research Publications
The discovery of transiting planets around bright stars holds the potential to greatly enhance our understanding of planetary atmospheres. In this work we present the search for transits of HD 168443b, a massive planet orbiting the bright star HD 168443 (V = 6.92) with a period of 58.11 days. The high eccentricity of the planetary orbit (e = 0.53) significantly enhances the a priori transit probability beyond that expected for a circular orbit, making HD 168443 a candidate for our ongoing Transit Ephemeris Refinement and Monitoring Survey. Using additional radial velocities from Keck High Resolution Echelle Spectrometer, we refined the …
Retired A Stars And Their Companions. Vii. 18 New Jovian Planets, John Asher Johnson, Christian Clanton, Andrew W. Howard, Brendan P. Bowler, Gregory W. Henry, Geoffrey W. Marcy, Justin R. Crepp, Michael Endl, William D. Cochran, Phillip J. Macqueen, Jason T. Wright, Howard Isaacson
Retired A Stars And Their Companions. Vii. 18 New Jovian Planets, John Asher Johnson, Christian Clanton, Andrew W. Howard, Brendan P. Bowler, Gregory W. Henry, Geoffrey W. Marcy, Justin R. Crepp, Michael Endl, William D. Cochran, Phillip J. Macqueen, Jason T. Wright, Howard Isaacson
Information Systems and Engineering Management Research Publications
We report the detection of 18 Jovian planets discovered as part of our Doppler survey of subgiant stars at Keck Observatory, with follow-up Doppler and photometric observations made at McDonald and Fairborn Observatories, respectively. The host stars have masses 0.927 ⩽ M⋆/M☉ ⩽ 1.95, radii 2.5 ⩽ R⋆/R☉ ⩽ 8.7, and metallicities −0.46 ⩽ [Fe/H] ⩽+0.30. The planets have minimum masses 0.9 MJup ⩽ MPsin i ≲ 13 MJup and semimajor axes a ⩾ 0.76 AU. These detections represent a 50% increase in the number of planets known to orbit stars more massive than 1.5 M☉ and provide valuable additional …
Kepler And Ground-Based Transits Of The Exo-Neptune Hat-P-11b, Drake Deming, Pedro V. Sada, Brian Jackson, Steven W. Peterson, Eric Agol, Heather A. Knutson, Donald E. Jennings, Flynn Haase, Kevin Bays
Kepler And Ground-Based Transits Of The Exo-Neptune Hat-P-11b, Drake Deming, Pedro V. Sada, Brian Jackson, Steven W. Peterson, Eric Agol, Heather A. Knutson, Donald E. Jennings, Flynn Haase, Kevin Bays
Brian Jackson
We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields Rp = 4.31 R⊕ ± 0.06 R ⊕ and Rs = 0.683 R☉ ± 0.009 R☉, both about 3σ smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening …
Hubble Space Telescope Transmission Spectroscopy Of The Exoplanet Hd 189733b: High-Altitude Atmospheric Haze In The Optical And Near-Ultraviolet With Stis, David K. Sing, Frederic Pont, Suzanne Aigrain, David Charbonneau, Jean-Michel Désert, Neale P. Gibson, Ronald Gilliland, Wolfgang Hayek, Gregory W. Henry, Heather Knutson, Alain Lecavelier Des Etangs, Tsevi Mazeh, Avi Shporer
Hubble Space Telescope Transmission Spectroscopy Of The Exoplanet Hd 189733b: High-Altitude Atmospheric Haze In The Optical And Near-Ultraviolet With Stis, David K. Sing, Frederic Pont, Suzanne Aigrain, David Charbonneau, Jean-Michel Désert, Neale P. Gibson, Ronald Gilliland, Wolfgang Hayek, Gregory W. Henry, Heather Knutson, Alain Lecavelier Des Etangs, Tsevi Mazeh, Avi Shporer
Information Systems and Engineering Management Research Publications
We present Hubble Space Telescope (HST) optical and near-ultraviolet transmission spectra of the transiting hot Jupiter HD 189733b, taken with the repaired Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the range 2900–5700 Å and reach per exposure signal-to-noise ratio levels greater than 11 000 within a 500-Å bandwidth. We used time series spectra obtained during two transit events to determine the wavelength dependence of the planetary radius and measure the exoplanet’s atmospheric transmission spectrum for the first time over this wavelength range. Our measurements, in conjunction with existing HST spectra, now provide a broad-band transmission spectrum covering …
Detailed Abundances Of The Solar Twins 16 Cygni And B Cygni: Constraining Planet Formation Models, Simon C. Schuler, Katia Cunha, Verne V. Smith, Luan Ghezzi, Jeremy R. King, Constantine P. Deliyannis, Ann Merchant Boesgaard
Detailed Abundances Of The Solar Twins 16 Cygni And B Cygni: Constraining Planet Formation Models, Simon C. Schuler, Katia Cunha, Verne V. Smith, Luan Ghezzi, Jeremy R. King, Constantine P. Deliyannis, Ann Merchant Boesgaard
Publications
Results of a detailed abundance analysis of the solar twins 16 Cyg A and 16 Cyg B based on high-resolution, high signal-to-noise ratio echelle spectroscopy are presented. 16 Cyg B is known to host a giant planet while no planets have yet been detected around 16 Cyg A. Stellar parameters are derived directly from our high-quality spectra, and the stars are found to be physically similar, with ΔTeff = +43 K, Δ log g =−0.02 dex, and Δξ = +0.10 km s−1 (in the sense of A − B), consistent with previous findings. Abundances of 15 elements are derived and …
Revised Orbit And Transit Exclusion For Hd 114762b, Stephen R. Kane, Gregory W. Henry, Diana Dragomir, Debra A. Fischer, Andrew W. Howard, Xuesong Wang, Jason T. Wright
Revised Orbit And Transit Exclusion For Hd 114762b, Stephen R. Kane, Gregory W. Henry, Diana Dragomir, Debra A. Fischer, Andrew W. Howard, Xuesong Wang, Jason T. Wright
Information Systems and Engineering Management Research Publications
Transiting planets around bright stars have allowed the detailed follow-up and characterization of exoplanets, such as the study of exoplanetary atmospheres. The Transit Ephemeris Refinement and Monitoring Survey is refining the orbits of the known exoplanets to confirm or rule out both transit signatures and the presence of additional companions. Here we present results for the companion orbiting HD 114762 in an eccentric 84 day orbit. Radial velocity analysis performed on 19 years of Lick Observatory data constrain the uncertainty in the predicted time of mid-transit to ∼5 hr, which is less than the predicted one-half day transit duration. We …
A Spitzer Transmission Spectrum For The Exoplanet Gj 436b, Evidence For Stellar Variability, And Constraints On Dayside Flux Variations, Heather Knutson, Nikku Madhusudhan, Nicolas B. Cowan, Jessie L. Christiansen, Eric Agol, Drake Deming, Jean-Michel Désert, David Charbonneau, Gregory W. Henry, Derek Homeier, Jonathan Langton, Gregory Laughlin, Sara Seager
A Spitzer Transmission Spectrum For The Exoplanet Gj 436b, Evidence For Stellar Variability, And Constraints On Dayside Flux Variations, Heather Knutson, Nikku Madhusudhan, Nicolas B. Cowan, Jessie L. Christiansen, Eric Agol, Drake Deming, Jean-Michel Désert, David Charbonneau, Gregory W. Henry, Derek Homeier, Jonathan Langton, Gregory Laughlin, Sara Seager
Information Systems and Engineering Management Research Publications
In this paper, we describe a uniform analysis of eight transits and eleven secondary eclipses of the extrasolar planet GJ 436b obtained in the 3.6, 4.5, and 8.0 μm bands using the IRAC instrument on the Spitzer Space Telescope between UT 2007 June 29 and UT 2009 February 4. We find that the best-fit transit depths for visits in the same bandpass can vary by as much as 8% of the total (4.7σ significance) from one epoch to the next. Although we cannot entirely rule out residual detector effects or a time-varying, high-altitude cloud layer in the planet's atmosphere as …
Abundances Of Stars With Planets: Trends With Condensation Temperature, Simon C. Schuler, Davin Flateau, Katia Cunha, Jeremy R. King, Luan Ghezzi, Verne V. Smith
Abundances Of Stars With Planets: Trends With Condensation Temperature, Simon C. Schuler, Davin Flateau, Katia Cunha, Jeremy R. King, Luan Ghezzi, Verne V. Smith
Publications
Precise abundances of 18 elements have been derived for 10 stars known to host giant planets from high signal-to-noise ratio, high-resolution echelle spectroscopy. Internal uncertainties in the derived abundances are typically 0.05 dex. The stars in our sample have all been previously shown to have abundances that correlate with the condensation temperature (Tc) of the elements in the sense of increasing abundances with increasing Tc; these trends have been interpreted as evidence that the stars may have accreted H-depleted planetary material. Our newly derived abundances also correlate positively with Tc, although slopes of linear least-square fits to the [m/H]–Tc relations …
Improved Orbital Parameters And Transit Monitoring For Hd 156846b, Stephen R. Kane, Andrew W. Howard, Genady Pilyavsky, Suvrath Mahadevan, Gregory W. Henry, Kaspar Von Braun, David R. Ciardi, Diana Dragomir, Debra A. Fischer, Eric L. N. Jensen, Gregory Laughlin, Solange V. Ramirez, Jason T. Wright
Improved Orbital Parameters And Transit Monitoring For Hd 156846b, Stephen R. Kane, Andrew W. Howard, Genady Pilyavsky, Suvrath Mahadevan, Gregory W. Henry, Kaspar Von Braun, David R. Ciardi, Diana Dragomir, Debra A. Fischer, Eric L. N. Jensen, Gregory Laughlin, Solange V. Ramirez, Jason T. Wright
Information Systems and Engineering Management Research Publications
HD 156846b is a Jovian planet in a highly eccentric orbit (e = 0.85) with a period of 359.55 days. The pericenter passage at a distance of 0.16 AU is nearly aligned to our line of sight, offering an enhanced transit probability of 5.4% and a potentially rich probe of the dynamics of a cool planetary atmosphere impulsively heated during close approach to a bright star (V = 6.5). We present new radial velocity (RV) and photometric measurements of this star as part of the Transit Ephemeris Refinement and Monitoring Survey. The RV measurements from the Keck–High Resolution Echelle Spectrometer …
The Nasa-Uc Eta-Earth Program. Iii. A Super-Earth Orbiting Hd 97658 And A Neptune-Mass Planet Orbiting Gl 785*, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, Gregory W. Henry, Howard Isaacson, Jeff A. Valenti, Jay Anderson, Nikolai Piskunov
The Nasa-Uc Eta-Earth Program. Iii. A Super-Earth Orbiting Hd 97658 And A Neptune-Mass Planet Orbiting Gl 785*, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, Gregory W. Henry, Howard Isaacson, Jeff A. Valenti, Jay Anderson, Nikolai Piskunov
Information Systems and Engineering Management Research Publications
We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modeling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msin i = 8.2 ± 1.2 M⊕, orbital period P = 9.494 ± 0.005 days, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msin i = 21.6 ± 2.0 M⊕, P = 74.39 ± 0.12 days, and orbital eccentricity e = 0.30 ± 0.09. Photometric …