IA/U.Porto Seminar - The battle between exoplanets and stellar activity - 7 junho 2017

Discovering Earth-like exoplanets is mainly being challenged by stellar activity, especially when using the radial velocity (RV) technique. Even when the presence of a transiting planet and hence its period are known, stellar activity can be the main barrier in nailing down the correct amplitude of the RV signal. Only by understanding the variable signals imposed by the star itself will we be able to find the underlying planetary signals.

 

In this talk I will review the activity problem in exoplanet research. I will present a new tool, using the Bayesian general Lomb-Scargle periodogram, that can be used for the purpose of identifying periodicities caused by stellar activity, based on the principle that stellar activity signals are variable and incoherent whilst planet-induced signals are stable. I will also explain about a new technique of extracting information on the stellar magnetic field directly from the intensity spectrum in order to disentangle the stellar magnetic signal from the signals from Earth-like planets.