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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

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Tennessee State University

2007

Planetary systems

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Two Jovian-Mass Planets In Earthlike Orbits, Sarah E. Robinson, Gregory Laughlin, Steve Vogt, Debra A. Fischer, R. Paul Butler, Geoffrey W. Marcy, Gregory W. Henry, Peter Driscoll, Genya Takeda, John A. Johnson Dec 2007

Two Jovian-Mass Planets In Earthlike Orbits, Sarah E. Robinson, Gregory Laughlin, Steve Vogt, Debra A. Fischer, R. Paul Butler, Geoffrey W. Marcy, Gregory W. Henry, Peter Driscoll, Genya Takeda, John A. Johnson

Information Systems and Engineering Management Research Publications

We report the discovery of two new planets: a 1.94 MJup planet in a 1.8 yr orbit of HD 5319, and a 2.51 MJup planet in a 1.1 yr orbit of HD 75898. The measured eccentricities are 0.12 for HD 5319b and 0.10 for HD 75898b, and Markov chain Monte Carlo simulations based on the derived orbital parameters indicate that the radial velocities of both stars are consistent with circular planet orbits. With low eccentricity and 1 AU < a < 2 AU, our new planets have orbits similar to terrestrial planets in the solar system. The radial velocity residuals of both stars have significant trends, likely arising from substellar or low-mass stellar companions.


The Rotation Period Of The Planet-Hosting Star Hd 189733, Gregory W. Henry, Joshua N. Winn Nov 2007

The Rotation Period Of The Planet-Hosting Star Hd 189733, Gregory W. Henry, Joshua N. Winn

Information Systems and Engineering Management Research Publications

We present synoptic optical photometry of HD 189733, the chromospherically active parent star of one of the most intensively studied exoplanets. We have significantly extended the timespan of our previously reported observations and refined the estimate of the stellar rotation period by more than an order of magnitude: P = 11.953 ± 0.009 days. We derive a lower limit on the inclination of the stellar rotation axis of 54° (with 95% confidence), corroborating earlier evidence that the stellar spin axis and planetary orbital axis are well aligned.


Five Intermediate-Period Planets From The N2k Sample, Debra A. Fischer, Steve Vogt, Geoffrey W. Marcy, R. Paul Butler, Bun'ei Sato, Gregory W. Henry, Sarah E. Robinson, Gregory Laughlin, Shigeru Ida, Eri Toyota, Masashi Omiya, Peter Driscoll, Genya Takeda, Jason T. Wright, John A. Johnson Nov 2007

Five Intermediate-Period Planets From The N2k Sample, Debra A. Fischer, Steve Vogt, Geoffrey W. Marcy, R. Paul Butler, Bun'ei Sato, Gregory W. Henry, Sarah E. Robinson, Gregory Laughlin, Shigeru Ida, Eri Toyota, Masashi Omiya, Peter Driscoll, Genya Takeda, Jason T. Wright, John A. Johnson

Information Systems and Engineering Management Research Publications

We report the detection of five Jovian-mass planets orbiting high-metallicity stars. Four of these stars were first observed as part of the N2K program, and exhibited low rms velocity scatter after three consecutive observations. However, follow-up observations over the last 3 years now reveal the presence of longer period planets with orbital periods ranging from 21 days to a few years. HD 11506 is a G0 V star with a planet of M sin i = 4.74 MJup in a 3.85 yr orbit. HD 17156 is a G0 V star with a 3.12 MJup planet in a 21.2 day orbit. …


A Determination Of The Spin-Orbit Alignment Of The Anomalously Dense Planet Orbiting Hd 149026, Aaron S. Wolf, Gregory Laughlin, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt Sep 2007

A Determination Of The Spin-Orbit Alignment Of The Anomalously Dense Planet Orbiting Hd 149026, Aaron S. Wolf, Gregory Laughlin, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt

Information Systems and Engineering Management Research Publications

We report 35 radial velocity measurements of HD 149026 taken with the Keck Telescope. Of these measurements, 15 were made during the transit of the companion planet HD 149026b, which occurred on 2005 June 25. These velocities provide a high-cadence observation of the Rossiter-McLaughlin effect, the shifting of photospheric line profiles that occurs when a planet occults a portion of the rotating stellar surface. We combine these radial velocities with previously published radial velocity and photometric data sets and derive a composite best-fit model for the star-planet system. This model confirms and improves previously published orbital parameters, including the remarkably …


The Transit Light Curve Project. V. System Parameters And Stellar Rotation Period Of Hd 189733, Joshua N. Winn, Matthew J. Holman, Gregory W. Henry, Anna Roussanova, Keigo Enya, Yuzuru Yoshii, Avi Shporer, Tsevi Mazeh, John Asher Johnson, Norio Narita Mar 2007

The Transit Light Curve Project. V. System Parameters And Stellar Rotation Period Of Hd 189733, Joshua N. Winn, Matthew J. Holman, Gregory W. Henry, Anna Roussanova, Keigo Enya, Yuzuru Yoshii, Avi Shporer, Tsevi Mazeh, John Asher Johnson, Norio Narita

Information Systems and Engineering Management Research Publications

We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning 2 yr. Using the transit photometry, we determine the stellar and planetary radii and the photometric ephemeris. Outside of transits, there are quasi-periodic flux variations with a 13.4 day period that we attribute to stellar rotation. In combination with previous results, we derive upper limits on the orbital eccentricity and on the true angle between the stellar rotation axis and planetary orbit (as opposed to the angle between the projections of those axes on the sky).