Colloquium on Nov. 27, 2019
One year in the life of the fast rotator AB Doradus
Speaker: Panagiotis Ioannidis (Hamburg Univ.)
Venue: Room 2111, SWIFAR Building
Time: 3:00 PM, Wednesday, November 27, 2019
Abstract:
One the key properties of stars in order to understand their behavior is their rotation period. In most of the cases measuring the rotation period of stars is possible by following the movement of active regions which rotate with the star. Studies based on data from the Kepler satellite showed that long term and uninterrupted observations of stars can allow us to measure with more confidence the rotation period and temporal evolution of spots. With the Transiting Exoplanet Survey Satellite (TESS) we can now proceed one step further, i.e., to study not random stars, limited by the observation sample of a mission, but rather well known and previously studied stars with specific properties (e.g. known planet hosts, flare stars, pulsators etc.) Following that principal we analyzed one year of data of the fast rotator AB Dor, as observed from TESS. We measure the rotation period of AB Dor and we study the evolution of its active regions, which appear to be highly preferential, with long life times and what we interpret as small differential rotation. With the confirmation of the activity features of a heavily studied star as AB Dor, we feel confident that we can proceed with similar studies on planet host stars which will allow us to better understand their properties and thus improve the characterization of their planets.