Sunspots Detected on Hot Jupiter WASP-85Ab's Host Star

Starspots on WASP-85

Authors:

Močnik et al

Abstract:

By analysing K2 short-cadence observations we detect starspots on WASP-85A, the host star of the hot Jupiter WASP-85Ab. The star shows a rotational modulation with a period of 13.6 \pm 0.1 d. The absence of repeated occultations of the same spots suggests that the planet's orbit is not aligned with the star's rotational axis (\lambda>10^{\circ}). There are no significant transit-timing variations and thus no evidence of any additional planet in the system. Given the pronounced rotational modulation we are only able to place an upper limit of 100 parts per million for any phase-curve modulations and the secondary eclipse.