Substellar Companions to Seven Evolved Intermediate-Mass Stars
Substellar Companions to Seven Evolved Intermediate-Mass Stars
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DOI：
10.1093/pasj/64.6.135
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发表时间：
2012-07
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影响因子：
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通讯作者：
B. Sato;M. Omiya;H. Harakawa;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;H. Izumiura;E. Kambe;Y. Takeda;Michitoshi Yoshida;Y. Itoh;H. Ando;E. Kokubo;S. Ida
本文报道了冈山天体物理观测站对7颗中等质量恒星的亚星伴星的精确多普勒观测。o UMa（G4 II-III）是一颗质量为3.1 M_sun的巨星，其母行星的最小质量为m_2sini=4.1 M_J，轨道周期为P=1630 d，离心率为e=0.13。这是迄今为止发现的第一颗围绕质量大于3 M太阳的恒星运行的候选行星（< 13 M J）. o CrB（K 0 III）是一颗2.1 M太阳巨星，其行星m_2sini=1.5 M J，轨道187.8 d，e=0.19。这是迄今为止发现的质量最小的行星之一，围绕着~2 M太阳恒星。HD 5608（K 0 IV）是一颗1.6 M太阳的亚巨星，它有一颗质量为m_2sini=1.4 M_J的行星，轨道为793 d，e=0.19。这颗星星也呈现出线速度的趋势，暗示着它的外部有一颗质量更大的伴星。75 Cet（G3 III：）是一颗2.5 M的太阳巨星，在692 d的轨道上有一颗m_2sini=3.0 M_J的行星，轨道e=0.12。该星星还显示出可能的额外周期约为200 d和1880 d，速度振幅约为7- 10 m/s，尽管这些在现阶段并不重要。Nu Oph（K 0 III）是一颗3.0 M太阳巨星，有两颗褐矮星伴星m_2sini= 24 M_J和27 M_J，轨道分别为P=530.3 d和3190 d，e=0.126和0.17，由Quirrenbach等人（2011）独立宣布。周期之比接近1：6，表明伴星处于平均运动共振状态。我们还独立地确认了围绕k CrB（K 0 III-IV）和HD 210702（K1 IV）的行星，这两颗行星分别由约翰逊等人（2008）和约翰逊等人（2007 a）宣布。所得的轨道参数与前人的结果一致。
We report the detections of substellar companions orbiting around seven evolved intermediate-mass stars from precise Doppler measurements at Okayama Astrophysical Observatory. o UMa (G4 II-III) is a giant with a mass of 3.1 M_sun and hosts a planet with minimum mass of m_2sini=4.1 M_J in an orbit with a period P=1630 d and an eccentricity e=0.13. This is the first planet candidate (< 13 M_J) ever discovered around stars more massive than 3 M_sun. o CrB (K0 III) is a 2.1 M_sun giant and has a planet of m_2sini=1.5 M_J in a 187.8 d orbit with e=0.19. This is one of the least massive planets ever discovered around ~2 M_sun stars. HD 5608 (K0 IV) is an 1.6 M_sun subgiant hosting a planet of m_2sini=1.4 M_J in a 793 d orbit with e=0.19. The star also exhibits a linear velocity trend suggesting the existence of an outer, more massive companion. 75 Cet (G3 III:) is a 2.5 M_sun giant hosting a planet of m_2sini=3.0 M_J in a 692 d orbit with e=0.12. The star also shows possible additional periodicity of about 200 d and 1880 d with velocity amplitude of ~7--10 m/s, although these are not significant at this stage. nu Oph (K0 III) is a 3.0 M_sun giant and has two brown-dwarf companions of m_2sini= 24 M_J and 27 M_J, in orbits with P=530.3 d and 3190 d, and e=0.126 and 0.17, respectively, which were independently announced by Quirrenbach et al. (2011). The ratio of the periods is close to 1:6, suggesting that the companions are in mean motion resonance. We also independently confirmed planets around k CrB (K0 III-IV) and HD 210702 (K1 IV), which had been announced by Johnson et al. (2008) and Johnson et al. (2007a), respectively. All of the orbital parameters we obtained are consistent with the previous results.