Starspots and the dynamic evolution of hot-Jupiter exoplanet systems

When a hot-Jupiter transits its host star and crosses an active region there is a possibility that it will occult a starspot. When this happens a starspot anomaly is usually seen in the resulting transit lightcurve. Generally viewed as a nuisance, the most common approach is to remove the affected data points before performing an analysis to determine the lightcurve properties. However, when a starspot anomaly is found in transit photometry it can allow a wealth of information to be discovered. Apart from determining the physical properties of the starspot (such as position, size and temperature) if a starspot anomaly is found in two sets of transit photometry and is due to the same starspot it is then possible to determine the stellar rotation period at the given latitude of the starspot. It is also possible to measure the sky-projected stellar obliquity of the system which can then begin to shed some light on the primary mechanism of the dynamical evolution of the system.

Speaker: Jeremy Tregloan-Reed, SETI