A planet around the evolved intermediate-mass star HD 110014

• Autor(a) principal: Medeiros, José Renan de
• Data de Publicação: 2009
• Outros Autores: Setiawan, J., Hatzes, A. P., Pasquini, L., Girardi, L., Udry, S., Döllinger, M. P., Silva, L. da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/28995; https://doi.org/10.1051/0004-6361/200911658
• topic: 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, 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 MJup. 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.