Activity of close-in planet hosts: probing mass loss and star-planet interactions

Using the Robert Stobie Spectrograph on the Southern African Large Telescope, we have generated a homogeneous database of magnetic activity metrics for close-in hosts, the majority of which host hot Jupiters. We find over one third of main sequence hosts have sub-basal activity, providing compelling evidence of atmospheric mass loss from highly irradiated planets. We also find strong evidence for star-planet interactions.