CfA Colloquium Schedule Spring 2008
 15 May 2008

15 May 2008

Speaker: Michel Mayor (University of Geneva)

Title: Cecilia Payne-Gaposchkin Lecture:
Exoplanets : The Road to Earth Twins


In the last thirteen years, about 300 exoplanets have been detected. These discoveries have revealed the impressive diversity of exoplanet orbital properties.

The past years have also witnessed a remarkable improvement of the precision of radial velocity measurements with a gain of about a factor 100. Thanks to the HARPS spectrograph installed in 2003 at la Silla Observatory, numerous planets with masses as small as a few earth-masses have been detected. Several statistical properties are already emerging and help constraining the formation mechanisms of these systems.

Is it possible to expect further significant progresses of Doppler measurements? Such a possibility could be of interest to permit radial velocity follow-up measurements of planetary transit candidates expected from the COROT and KEPLER space missions: the goal being to get a precise determination of mass-radius relations from terrestrial planets to brown dwarfs. Recently, we have been able to get a first insight in the internal composition of a Neptune analogue from ground based observations.

A radial velocity precision at the level of 0.1 m/s does not seem out of reach. With an observing strategy adapted to minimize the influence of the stellar intrinsic variability (magnetic activity, acoustic modes) we should be in position to explore statistical properties of terrestrial planetary systems.

Video of the Presentation (Talks can be viewed with RealPlayer. Free download is available from )


Section Photo