EDP Sciences
Free access
Volume 485, Number 3, July III 2008
Page(s) 859 - 864
Section Planets and planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20079175
Published online 06 May 2008

A&A 485, 859-864 (2008)
DOI: 10.1051/0004-6361:20079175

HD 75289Ab revisited

Searching for starlight reflected from a hot Jupiter
F. Rodler1, 2, M. Kürster1, and T. Henning1

1  Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
    e-mail: rodler@mpia.de
2  Institut für Astronomie, Universität Wien, Türkenschanzstrasse 17, 1180 Vienna, Austria

Received 30 November 2007 / Accepted 29 February 2008

Aims. We attempt to detect starlight reflected from a hot Jupiter, orbiting the main-sequence star HD 75289Ab. We report a revised analysis of observations of this planetary system presented previously by another research group.
Methods. We analyze high-precision, high-resolution spectra, collected over four nights using UVES at the VLT/UT2, by way of data synthesis. We try to interpret our data using different atmospheric models for hot Jupiters.
Results. We do not find any evidence for reflected light, and, therefore, establish revised upper limits to the planet-to-star flux ratio at the 99.9% significance level. At high orbital inclinations, where the best sensitivity is attained, we can limit the relative reflected radiation to be less than $\epsilon =
6.7\times10^{-5}$ assuming a grey albedo, and $\epsilon=8.3\times10^{-5}$ assuming an Class IV function, respectively. This implies a geometric albedo smaller than p=0.46 and p=0.57, for the grey albedo and the Class IV albedo shape, respectively, assuming a planetary radius of $1.2~{R_{\rm Jup}}$.

Key words: methods: data analysis -- techniques: radial velocities -- stars: individual: HD 75289A -- stars: planetary systems

© ESO 2008