A simple model to describe intrinsic stellar noise for exoplanet detection around red giants
Thomas North (University of Birmingham), William Chaplin (University of Birmingham), et al.

In spite of the huge advances in exoplanet research provided by the NASA Kepler Mission, there remains a dearth of transit detections around evolved stars. Here we present a reformulation of the noise properties of red-giant stars, where the intrinsic stellar granulation and oscillations present the dominant noise sources. This noise model is then used to make transit signal-to-noise predictions for a 6400-strong cohort of Kepler stars that have already been identified as evolved stars on the red-giant branch. We discuss predictions of the fraction of red-giant targets that might have detectable planets. Subject to different assumptions for the underlying planet population our results suggest it may be possible to double the number of detected transiting planets around red giants, using current Kepler data.