Planetary Companions to Three Evolved Intermediate-Mass Stars: HD 2952, HD 120084, and omega Serpentis
Planetary Companions to Three Evolved Intermediate-Mass Stars: HD 2952, HD 120084, and omega Serpentis
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DOI：
10.1093/pasj/65.4.85
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发表时间：
2013-04
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通讯作者：
B. Sato;M. Omiya;H. Harakawa;Yujuan Liu;H. Izumiura;E. Kambe;Y. Takeda;Michitoshi Yoshida;Y. Itoh;H. Ando;E. Kokubo;S. Ida
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作者：
B. Sato;M. Omiya;H. Harakawa;Yujuan Liu;H. Izumiura;E. Kambe;Y. Takeda;Michitoshi Yoshida;Y. Itoh;H. Ando;E. Kokubo;S. Ida
我们报告了冈山天体物理观测站通过精确的径向速度测量发现的围绕三颗演化的中等质量恒星运行的行星伴星。 HD 2952 (K0III, 2.5 M_sun) 和 omega Ser (G8III, 2.2 M_sun) 拥有一颗质量相对较低的行星，最小质量为 m_2sin i=1.6 M_J 和 1.7 M_J，在近圆形轨道上运行，周期分别为 P=312 和 277 d。 HD 120084（G7 III，2.4 M_sun）拥有一颗 m_2sin i=4.5 M_J 的偏心行星，其轨道 P=2082 d，偏心率 e=0.66。这颗行星是迄今为止发现的围绕已演化中等质量恒星的偏心率最大的行星之一，几乎所有恒星的偏心率都小于 0.4。我们还表明，通过高节奏观测，G巨星的恒星振荡的径向速度变化至少在一周的时间尺度内可以平均到几米/秒的水平以下，这使我们能够在短周期轨道上探测到超级地球和海王星质量的行星，甚至围绕这样的巨星运行。
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.