2005/05/25 by J. Setiawan, J. Rodmann, L. da Silva +9 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:200500133
5 pages, 5 figures
arxiv created 2005/05/25 · openalex publication_date 2005/06/21 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/04
We report the discovery of a substellar companion to the intermediate-mass star HD 11977 (G5 III). Radial velocities of this star have been monitored for five years with FEROS at the 1.52-m ESO and later at the 2.2-m MPG/ESO telescope in La Silla, Chile. Based on the collected data we calculated an orbital solution with a period of , a semi-amplitude of , and an eccentricity of . The period of the radial-velocity variation is longer than that of the estimated stellar rotation, rendering it unlikely that rotational modulation is the source of the variation in the radial velocity. This hypothesis is supported by the absence of a correlation between stellar activity indicators and radial-velocity variation. By determining a primary stellar mass of , the best-fit minimum mass of the companion and semi-major axis of the orbit are and , respectively. An upper limit for the mass of the companion of has been calculated from Hipparcos astrometric measurements. Although the possibility of a brown-dwarf companion cannot be excluded, HD 11977 B is one of the few planet candidates detected around an intermediate-mass star. The progenitor main-sequence star of HD 11977 is probably an A-type star. This discovery gives an indirect evidence for planetary companions around early type main-sequence stars.