Description
In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity (RV) planet searches. Supergranulation introduces RV variations on timescales of 1-2 days with amplitudes of 0.5-1 m/s, considerably larger than the expected 10 cm/s signal from Earth-like planets. I will present new work focused on mitigating the impact of supergranulation using Gaussian Processes in the time domain. I will apply this new method to HARPS-N solar data sets, and show how this method has led to the discovery of a ‘supergranulation cycle’, in phase with the activity cycle of the Sun. I will also discuss observational strategies that can be employed to characterise supergranulation in other stars, a critical step in the search for Earth-twins. Finally, I will show that by modelling the supergranulation signal in this way, we can improve the detection of planets with smaller RV signals, bringing us closer to identifying Earth-like exoplanets.
