We report the discovery of a massive planetary companion orbiting the young disc star HD 81040. Based on five years of precise radial-velocity measurements with the HIRES and ELODIE spectrographs, we derive a spectroscopic orbit with a period P=1001.0 days and eccentricity e=0.53. The inferred minimum mass for the companion of m2sini=6.86 MJup places it in the high-mass tail of the extrasolar planet mass distribution. The radial-velocity residuals exhibit a scatter significantly larger than the typical internal measurement precision of the instruments. Based on an analysis of the Ca II H and K line cores, this is interpreted as an activity-induced phenomenon. However, we find no evidence for the period and magnitude of the radial-velocity variations to be caused by stellar surface activity. The observed orbital motion of HD 81040 is thus best explained with the presence of a massive giant planet companion.
@article{arxiv.astro-ph/0511679,
title = {A Massive Planet to the Young Disc Star HD 81040},
author = {A. Sozzetti and S. Udry and S. Zucker and G. Torres and J. L. Beuzit and D. W. Latham and M. Mayor and T. Mazeh and D. Naef and C. Perrier and D. Queloz and J. -P. Sivan},
journal= {arXiv preprint arXiv:astro-ph/0511679},
year = {2009}
}
Comments
9 pages, 5 figures, 4 tables. Accepted for publication in A&A