Planets around young active solar-type stars: assessing detection capabilities from a non-stabilized spectrograph

Abstract

Short-orbit gas giant planet formation/evolution mechanisms are still not well understood. One promising pathway to discriminate between mechanisms is to constrain the occurrence rate of these peculiar exoplanets at the earliest stage of the system’s life. However, a major limitation when studying newly born stars is stellar activity. This cocktail of phenomena triggered by fast rotation, strong magnetic fields and complex internal dynamics, especially present in very young stars, compromises our ability to detect exoplanets. In this paper, we investigated the limitations of such detections in the context of already acquired data solely using radial velocity data acquired with a non-stabilised spectrograph. We employed two strategies: Doppler Imaging and Gaussian Processes and could confidently detect Hot Jupiters with semi-amplitude of 100 m s−1buried in the stellar activity. We also showed the advantages of theGaussian Process approach in this case. This study serves as a proof of concept to identify potential candidates for follow-up observations or even discover such planets in legacy datasets available to the community.