A planet around the evolved intermediate-mass star HD 110014 ^*,**

¹ Departamento de Física, Universidade Federal do Rio Grande do Norte, Natal, Brazil e-mail: renan@dfte.ufrn.br
² Max-Planck-Institut fur Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
³ Thueringer Landessternwarte, Tautenburg, Germany
⁴ European Southern Observatory, Garching bei Munchen, Germany
⁵ Osservatorio Astronomico di Padova-INAF, Padova, Italy
⁶ Geneva Observatory, Geneva University, Geneva, Switzerland
⁷ Observatório Nacional, Rio de Janeiro, Brazil

Received: 13 January 2009
Accepted: 10 July 2009

Abstract

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 , is slightly metal rich with [Fe/H] = 0.19 and a rotational velocity  = 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  days. A Keplerian orbit, with an eccentricity , yields a minimum mass  = 11.09 . 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.