Five Intermediate-Period Planets from the N2K Sample

• Published in: The Astrophysical journal Vol. 669; no. 2; pp. 1336 - 1344
• Main Authors: Fischer, Debra A, Vogt, Steven S, Marcy, Geoffrey W, Butler, R. Paul, Sato, Bun’ei, Henry, Gregory W, Robinson, Sarah, Laughlin, Gregory, Ida, Shigeru, Toyota, Eri, Omiya, Masashi, Driscoll, Peter, Takeda, Genya, Wright, Jason T, Johnson, John A
• Format: Journal Article
• Language: English
• Published: Chicago, IL IOP Publishing 10.11.2007; University of Chicago Press
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; stars: individual (HD 11506, HD 17156, HD 125612, HD 170469, HD 231701); Planets; planetary systems; Planetary system
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/521869

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 GO V star with a planet of Msin i = 4.74 M sub(Jup) in a 3.85 yr orbit. HD 17156 is a G0 V star with a 3.12 Wjup planet in a 21.2 day orbit. The eccentricity of this orbit is 0.67, one of the highest known for a planet with a relatively short period. The orbital period for this planet places it in a region of parameter space where relatively few planets have been detected. HD 125612 is a G3 V star with a planet of Msin i = 3.5 M sub(Jup) in a 1.4 yr orbit. HD 170469 is a G5 IV star with a planet of Msin i = 0.67 M sub(Jup) in a 3.13 year orbit HD 231701 is an F8 V star with planet of 1.08 M sub(Jup) in a 142 day orbit. All of these stars have supersolar metallicity. Three of the five stars were observed photometrically, but showed no evidence of brightness variability. A transit search conducted for HD 17156 was negative, but covered only 25% of the search space, and so is not conclusive.