Talk

Differential rotation and magnetic cycles in Gaia rotating variable stars

Elisa Distefano, INAF

The Gaia Data Release 2 (DR2) reported the rotation period P_{Rot} and the amplitude A of light curve induced by rotational modulation for about 150000 late-type stars. The analysis of the P_{Rot}-A diagram permitted to identify three different families of rotating stars that should be characterized by different magnetic properties. A better understanding of this diagram could be achieved with the help of information on the stellar magnetic activity coming from long-term photometry. Indeed long term photometry can be exploited to study magnetic activity cycles and to infer information on the surface differential rotation (see e.g. Distefano et al. 2016) that is a key ingredient in the stellar dynamo models. In the present work we study activity cycles and differential rotation in a small sample of 46 DR2 sources for which ASAS long term photometry is available with the aim to get insights to interpret the feature of the GAIA P_{rot}-A diagram.