A Massive Substellar Companion to the Massive Giant HD 119445

作者：Omiya Masashi^*; Izumiura Hideyuki; Han Inwoo; Lee Byeong Cheol; Sato Bun'ei; Kambe Eiji; Kim Kang Min; Yoon Tae Seog; Yoshida Michitoshi; Masuda Seiji; Toyota Eri; Urakawa Seitaro; Takada Hidai Masahide

来源：Publications of the Astronomical Society of Japan, 2009, 61(4): 825-831.

DOI：10.1093/pasj/61.4.825

• stars: individual (HD 119445)
• star: low-mass, brown dwarfs
• techniques: radial velocities

We detected a brown dwarf-mass companion around the intermediate-mass giant star HD 119445 (G6111) using the Doppler technique. This discovery is the first result from a Korean-Japanese planet search program based on precise radial velocity measurements. The radial velocity of this star exhibits a periodic Keplerian variation with a period, semiamplitude, and eccentricity of 410.2 d, 413.5 m s(-1), and 0.082, respectively. Adopting a stellar mass of 3.9 M(circle dot), we were able to confirm the presence of a massive substellar companion with a semimajor axis of 1.71 AU and a minimum mass of 37.6 M(J), which falls in the middle of the brown dwarf-mass region. This substellar companion is the most massive ever discovered within 3 AU of a central intermediate-mass star. The host star also ranks among the most massive stars with substellar companions ever detected by the Doppler technique. This result supports the current view of substellar systems that more massive substellar companions tend to exist around more massive stars, and may further constrain substellar system formation mechanisms.

• 出版日期2009
• 单位中国科学院国家天文台