A planet around the evolved intermediate-mass star HD 110014

作者：de Medeiros J R^*; Setiawan J; Hatzes A P; Pasquini L; Girardi L; Udry S; Doellinger M P; da Silva L

来源：Astronomy & Astrophysics, 2009, 504(2): 617-623.

DOI：10.1051/0004-6361/200911658

• stars: evolution
• technique: radial velocities
• stars: planetary systems
• stars late-type

Context. We found evidence for a sub-stellar companion around the K giant star HD 110014. This cool evolved star, with a spectral type K2III and an estimated mass between 1.9 and 2.4 M-circle dot, is slightly metal rich with [Fe/H] = 0.19 and a rotational velocity V sin i = 2.0 km s(-1).
Aims. To search for extrasolar planets around intermediate-mass stars and to improve our knowledge of the nature of radial velocity variations shown by G and K giant stars.
Methods. Based on radial velocity analysis, we found evidence for a substellar companion with a planetary mass and long orbital period. The Radial velocity variation of HD 110014 has been monitored from 2000 until 2007 with FEROS at 1.5 m ESO and at the 2.2 m MPG/ESO, HARPS at the 3.6 m ESO and Coralie at 1.2 m Leonard Euler swiss telescopes in La Silla observatory. The radial velocities were computed by using a cross-correlation technique. Line bisector, Hipparcos photometry and chromospheric lines were analyzed to exclude other root-causes for the radial velocity variability.
Results. We report the presence of an extrasolar planet around the giant star HD 110014, with an orbital period of 835.48 +/- 6.04 days. A Keplerian orbit, with an eccentricity e = 0.462 +/- 0.069, yields a minimum mass M sin i = 11.09 M-Jup. The analysis of the residuals shows evidence for a second RV variability with a period of 130 days and an amplitude of +/-100 ms(-1). Its nature is not completely clear, but a second planet is a possible explanation.

• 出版日期2009-9