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arXiv · 1304.4328

Planetary Companions to Three Evolved Intermediate-Mass Stars: HD 2952, HD 120084, and omega Serpentis

Bun'ei Sato·Masashi Omiya·Hiroki Harakawa·Yu-Juan Liu·Hideyuki Izumiura·Eiji Kambe·Yoichi Takeda·Michitoshi Yoshida·Yoichi Itoh·Hiroyasu Ando·Eiichiro Kokubo·Shigeru Ida
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Abstract

We report the detections of planetary companions orbiting around three evolved intermediate-mass stars from precise radial velocity measurements at Okayama Astrophysical Observatory. HD 2952 (K0III, 2.5 M_sun) and omega Ser (G8III, 2.2 M_sun) host a relatively low mass planet with minimum mass of m_2sin i=1.6 M_J and 1.7 M_J in nearly circular orbits with period of P=312 and 277 d, respectively. HD 120084 (G7 III, 2.4 M_sun) hosts an eccentric planet with m_2sin i=4.5 M_J in an orbit with P=2082 d and eccentricity of e=0.66. The planet has one of the largest eccentricities among those ever discovered around evolved intermediate-mass stars, almost all of which have eccentricity smaller than 0.4. We also show that radial velocity variations of stellar oscillations for G giants can be averaged out below a level of a few m/s at least in timescale of a week by high cadence observations, which enables us to detect a super-Earth and a Neptune-mass planet in short-period orbits even around such giant stars.

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Bun'ei Sato, Masashi Omiya, Hiroki Harakawa, Yu-Juan Liu, Hideyuki Izumiura, Eiji Kambe, Yoichi Takeda, Michitoshi Yoshida, Yoichi Itoh, Hiroyasu Ando, Eiichiro Kokubo, Shigeru Ida. 2013-04-17. Planetary Companions to Three Evolved Intermediate-Mass Stars: HD 2952, HD 120084, and omega Serpentis. https://doi.org/10.1093/pasj%2F65.4.85

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