Stellar variability: impact on the detection of low-mass planets

I. Boisse, X. Dumusque, N. C. Santos, J. Gomes da Silva, X. Bonfils, A. F. Lanza

Abstract.
Although many methodes are currently being used to search for planets orbiting other stars, the radial-velocity (RV) technique remains the most prolific. Moreover, transit surveys need RV follow-up to establish the planetary nature of their candidates and to measure their masses. This mass measurement, combined with the radius one via the transit light-curve, is crucial to have an estimation of exoplanets density. Ground-based RV measurements are then critical to explore the physical characterization of exoplanets.
Although extremely efficient, the RV technique is, however, an indirect method (as well as photometric transit detection or astrometry). One of the problems with this is the fact that periodic RV variations can in some cases be caused by some other mechanisms, not related to the presence of low-mass companions. Phenomena such as stellar pulsation, inhomogeneous convection, spots or magnetic cycles can prevent us from finding planets, they might degrade the parameters estimation, or give us false candidate, if they produce a stable periodic signal.
We consider the different kind of «noise » that are generated by stars, as well as the methods proposed and used to overcome this issue. The impact for the detection of other earths using high-precision RV instruments, like HARPS or ESPRESSO is considered.

PLATO Science Conference
Berlin, Germany
February 2011

Type: Poster