Seminar
Study of the planetary system HD 46375 with CoRoT and ground-based support

Abstract

At the end of 2008, on ideas of teams from the Observatoire de la Côte d’Azur (OCA) and IAC, the CoRoT satellite observed the star HD 46375, known to host a non-transiting Saturn-mass exoplanet with a 3.023 day period. HD 46375 is the brightest star with a known close-in planet in the CoRoT accessible field of view. As such, it was targeted by the CoRoT additional program and observed in a CCD normally dedicated to the asteroseismology program, to obtain an ultra-precise photometric lightcurve and detect or place upper limits on the brightness of the planet. In addition, a ground-based support was simultaneously performed with the high-resolution NARVAL spectro-polarimeter to constrain the stellar atmospheric and magnetic properties. In this seminar, I will present the main results, in particular the stellar constrain we obtained thanks to the detection of the oscillation mode signature and the plausible detection of the planetary signal, which, if confirmed with future observations, would be the first detection of phase changes in the visible for a non-transiting planet.