S316p.64 — Synthetic clusters of massive stars to test stellar evolution models

Date & Time

Aug 10th at 6:00 PM until 7:30 PM




Rating ( votes)

Author(s): Cyril Georgy2, Sylvia Ekström1, Anahi Granada1, Georges Meynet1, Nate Bastian3, Corinne Charbonnel1

Institution(s): 1. Geneva University, 2. Keele University, 3. Liverpool John Moores University

During the recent years, the Geneva stellar evolution group has published several sets of grids of stellar models, including the effect of rotation and with up to date input physics. These sets cover a wide range of initial masses, initial rotation rates and metallicities. In addition to these grids, we have also developed a toolbox (the SYCLIST code), allowing for the study of stellar populations as a function of time, and to build synthetic clusters of a given age.
In this talk, I will present the SYCLIST code and the various effects that it is able to account for: initial distributions of rotation velocities, effect of the angle of view on the look of fast rotating stars (gravity darkening). I will show how the account for a rotation velocities distribution affects the HRD and CMD of clusters at different ages.
Eventually, I will discuss how comparing our synthetic clusters with observed ones can help in understanding stellar physics. For example, I will show how the effects of rotation and of gravity darkening affects the region of the turn-off of young clusters. Rotation has also an impact on the look of the Hertzsprung gap of intermediate age clusters, by broadening the sequence of stars that lie in this region of the HRD.