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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.
Precise radial velocities from the Anglo-Australian Telescope confirm the presence of a rare short-period planet around the K0 giant HD 121056. An independent two-planet solution using the AAT data shows that the inner planet has P=89.1+/-0.1 days, a
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 $pm$ 0.02 days, a semi-amplitude of 51.1 $pm$ 1.4 ms, an eccentricit
The K2.5 dwarf HD 40307 has been reported to host three super-Earths. The system lacks massive planets and is therefore a potential candidate for having additional low-mass planetary companions. We re-derive Doppler measurements from public HARPS spe
We report the detection of two planetary mass companions to the solar-type star HD 155358. The two planets have orbital periods of 195.0 and 530.3 days, with eccentricities of 0.11 and 0.18. The minimum masses for these planets are 0.89 and 0.50 Jupi
We report the detection of a double planetary system orbiting around the evolved intermediate-mass star HD 4732 from precise Doppler measurements at Okayama Astrophysical Observatory (OAO) and Anglo-Australian Observatory (AAO). The star is a K0 subg