|
Description
Several studies showed that the magnetic activity of late-type main-sequence (MS) stars is characterized by different regimes and that their activity levels are well described by the Ross by number, Ro, defined as the ratio between the rotational period P_rot_ and the convective turnover time. Very young pre-main-sequence (PMS) stars show, similarly to MS stars, intense magnetic activity. However, they do not show clear activity-rotation trends, and it still debated which stellar parameters determine their magnetic activity levels. To bridge the gap between MS and PMS stars, we studied the activity-rotation relation in the young cluster h Persei, a ~13Myr old cluster, that contains both fast and slow rotators. The cluster members have ended their accretion phase and have developed a radiative core. It therefore offers us the opportunity of studying the activity level of intermediate-age PMS stars with different rotational velocities, excluding any interactions with the circumstellar environment We constrained the magnetic activity levels of h Per members by measuring their X-ray emission from a Chandra observation, while rotational periods were obtained previously in the framework of the MONITOR project. By cross-correlating these data, we collected a final catalog of 414 h Per members with known rotational period, effective temperature, and mass. In 169 of these, X-ray emission has also been detected.
|
