The Lick-Carnegie Survey: A New Two-Planet System Around the Star HD 207832

Abstract

Keck/HIRES precision radial velocities of HD 207832 indicate the presence of two Jovian-type planetary companions in Keplerian orbits around this G star. The planets have minimum masses of 0.56 and 0.73 Jupiter-masses with orbital periods of ~162 and ~1156 days, and eccentricities of 0.13 and 0.27, respectively. Stromgren b and y photometry reveals a clear stellar rotation signature of the host star with a period of 17.8 days, well separated from the period of the radial velocity variations, reinforcing their Keplerian origin. The values of the semimajor axes of the planets suggest that these objects have migrated from the region of giant planet formation to closer orbits. In order to examine the possibility of the existence of additional (small) planets in the system, we studied the orbital stability of hypothetical terrestrial-sized objects in the region between the two planets and interior to the orbit of the inner body. Results indicated that stable orbits exist only in a small region interior to planet b. However, the current observational data offer no evidence for the existence of additional objects in this system.

23 pages, 4 figures, 5 tables, accepted for publication in ApJ

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• Dynamical constraints on the origin of hot and warm Jupiters with close friends
• No difference in orbital parameters of RV-detected giant planets between 0.1 and 5 au in single vs multi-stellar systems
• Planetary system around LTT 1445A unveiled by ESPRESSO: Multiple planets in a triple M-dwarf system
• On the 3D secular dynamics of radial-velocity-detected planetary systems
• Binary frequency of planet-host stars at wide separations: A new brown dwarf companion to a planet-host star