Colloquium on Oct. 23th, 2019

Observing stellar dynamos in action

Speaker: Thomas Hackman (Helsinki)

Venue: Room 2111, SWIFAR Building

Time: 10:00 AM, Wednesday, 23th October, 2019

Abstract: 

Studying spots of late-type stars is crucial for understanding the  stellar dynamos believed to be the main mechanism causing cool spots in solar-type stars. In  order to unravel both long and short-term evolution it is important to  collect long time series of observations with regular intervals. Doppler  imaging is a very efficient technique to study surface spots on stars  that cannot be angularly resolved. I will present recent results based  mainly on high-resolution spectroscopic and spectropolarimetric monitoring of active late-type  stars. These include evidence of connection between activity states and surface magnetic field topology, but also more erratic behaviour in some stars.