A Double Planetary System around the Evolved Intermediate-Mass Star HD 4732

Authors :: Sato, Bun'ei
Omiya, Masashi
Wittenmyer, Robert A.
Harakawa, Hiroki
Nagasawa, Makiko
Izumiura, Hideyuki
Kambe, Eiji
Takeda, Yoichi
Yoshida, Michitoshi
Itoh, Yoichi
Ando, Hiroyasu
Kokubo, Eiichiro
Ida, Shigeru
Publication Year :: 2012
Abstract: 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 subgiant with a mass of 1.7 M_sun and solar metallicity. The planetary system is composed of two giant planets with minimum mass of msini=2.4 M_J, orbital period of 360.2 d and 2732 d, and eccentricity of 0.13 and 0.23, respectively. Based on dynamical stability analysis for the system, we set the upper limit on the mass of the planets to be about 28 M_J (i>5 deg) in the case of coplanar prograde configuration.<br />Comment: 12 pages, 7 figures, accepted for publication in ApJ