Planetary companions around the metal-poor star HIP 11952
Abstract
Aims. We carried out a radial-velocity survey to search for planets around metal-poor stars. In this paper we report the discovery of two planets around HIP 11952, a metal-poor star with [Fe/H]= -1.9 that belongs to our target sample. Methods. Radial velocity variations of HIP 11952 were monitored systematically with FEROS at the 2.2 m telescope located at the ESO La Silla observatory from August 2009 until January 2011. We used a cross-correlation technique to measure the stellar radial velocities (RV). Results. We detected a long-period RV variation of 290 d and a short-period one of 6.95 d. The spectroscopic analysis of the stellar activity reveals a stellar rotation period of 4.8 d. The Hipparcos photometry data shows intra-day variabilities, which give evidence for stellar pulsations. Based on our analysis, the observed RV variations are most likely caused by the presence of unseen planetary companions. Assuming a primary mass of 0.83 M\odot, we computed minimum planetary masses of 0.78 MJup for the inner and 2.93 MJup for the outer planet. The semi-major axes are a1 = 0.07 AU and a2 = 0.81 AU, respectively. Conclusions. HIP 11952 is one of very few stars with [Fe/H]< -1.0 which have planetary companions. This discovery is important to understand planet formation around metal-poor stars
Keywords
Cite
@article{arxiv.1208.4000,
title = {Planetary companions around the metal-poor star HIP 11952},
author = {J. Setiawan and V. Roccatagliata and D. Fedele and Th. Henning and A. Pasquali and M. V. Rodríguez-Ledesma and E. Caffau and U. Seemann and R. J. Klement},
journal= {arXiv preprint arXiv:1208.4000},
year = {2012}
}
Comments
Published in A&A