Found 2 talks width keyword CoRot

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Thursday June 23, 2011
Institut d'Astrophysique Spatiale; Université Paris Sud, Paris, France

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.


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Wednesday May 26, 2010
Laboratoire AIM, IRFU/DSM/CEA, Saclay, France

Abstract

Gamma Dor stars (M = 1.2-2.5 M⊙; spectral type A-F) are very interesting from an asteroseismic point of view. They show gravity modes, which are the only modes that provide information on the deep stellar interior. Observationally they are very challenging targets. Typical pulsation periods are of the order of a day and amplitudes are fairly small (below 0.05 mag; 2 km/s), making it extremely difficult to monitor the periodic variations from the ground. The asteroseismic space missions CoRoT and Kepler are providing uninterrupted time-series from space, with unprecedented accuracy, and hence promise a revolution in the study of gamma Dor stars. I will present results of the seismic analysis of CoRoT and Kepler gamma Dor targets, and the associated ground-based support observations, involving many telescopes at different observatories (including La Palma and Izaña).

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