Deep MMT Transit Survey of the Open Cluster M37 III: Stellar Rotation at 550 Myr

Understand

In the course of conducting a deep (14.5 ~< r ~< 23), 20 night survey for transiting planets in the rich ~550 Myr old open cluster M37 we have measured the rotation periods of 575 stars which lie near the cluster main sequence, with masses 0.2 Msun ~< M ~< 1.3 Msun.

• This is the largest sample of rotation periods for a cluster older than 500 Myr.
• Using this rich sample we investigate a number of relations between rotation period, color and the amplitude of photometric variability.
• Stars with M >~ 0.8 Msun show a tight correlation between period and mass with heavier stars rotating more rapidly.