München 2019 – wissenschaftliches Programm
EP 11.1: Vortrag
Freitag, 22. März 2019, 12:30–12:45, HS 19
Membership and rotation of solar- and low-mass stars in the open cluster NGC 3532 — •Dario J. Fritzewski1, Sydney A. Barnes1, David J. James2, and Klaus G. Strassmeier1 — 1Leibniz-Institut für Astrophysik Potsdam (AIP), Potsdam, Germany — 2Harvard-Smithsonian Center for Astrophysics, Cambridge, USA
Stellar rotation periods can be used as an empirical method to determine ages of cool main-sequence stars. By providing coeval (equal-age) populations of the same composition, but varying mass, Galactic open clusters provide an ideal means to construct and test this technique. However, they are often sparse and have incomplete membership lists.
We present the membership for the very populous, 300 Myr-old open cluster NGC 3532 constructed from radial velocity observations and Gaia DR2 proper motions. From photometric time-series observations of the open cluster we determined rotation periods for 200 stars, spanning the range from solar-mass to low-mass stars.
One of the complexities and opportunities in young open clusters is to study a rotational and magnetic transition from fast to slowly rotating stars. The results confirm the rotation-mass-age relation and provide new information about this transition.