2012/07/13 by Bun'ei Sato, Masashi Omiya, Hiroki Harakawa +8 · 56 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Brown dwarf #Eccentricity (behavior) #Giant planet #Orbit (dynamics) #Planet #Planetary system #Radial velocity #Stars #Stellar, planetary, and galactic studies #Subgiant #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.1093/pasj/64.6.135
published in Publications of the Astronomical Society of Japan 64(6) (Oxford University Press) · 21 pages, 14 figures, accepted for publication in PASJ
arxiv created 2012/07/13 · openalex publication_date 2012/12/25 · arxiv updated 2015/06/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We report on 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\odot , and hosts a planet with a minimum mass of m2 sin i= 4.1 M\rm J in an orbit with a period P= 1630 d and an eccentricity e= 0.13. This is the first planet candidate (\lt 13 M\rm J ) ever discovered around a star more massive than 3 M\odot . o CrB (K0 III) is a 2.1 M\odot giant, and has a planet of m2 sin i= 1.5 M\rm J in a 187.8 d orbit with e= 0.19. This is one of the least-massive planets ever discovered around an ∼ 2 M\odot star. HD 5608 (K0 IV) is an 1.6 M\odot subgiant hosting a planet of m2 sin i= 1.4 M\rm 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\odot giant hosting a planet of m2 sin i= 3.0 M\rm J in a 692 d orbit with e= 0.12. The star also shows a possible additional periodicity of about 200 d and 1880 d with a velocity amplitude of ∼ 7–10 m s-1 , although these are not significant at this stage. ν Oph (K0 III) is a 3.0 M\odot giant, and has two brown-dwarf companions of m2 sin i= 24 M\rm J and 27 M\rm 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, Reffert, and Bergmann (2011, AIP Conf. Proc. 1331, 102). 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 κ CrB (K0 III-IV) and HD 210702 (K1 IV), which were announced by Johnson et al. (2008, ApJ, 675, 784) and Johnson et al. (2007a, ApJ, 665, 785), respectively. All of the orbital parameters we obtained are consistent with the previous results.