Sidney Wolff

NOAO

The rotational properties of early B-type stars in low density environments are compared with those in high-density environments. The data show that (1) independent of environment, the rotation rates for stars in the mass range 6-12 solar masses do not change by more than 0.1 dex during the first 15 Myr after they reach the ZAMS; and (2) stars formed in high-density regions lack the cohort of slow rotators that dominate the low-density regions. This difference may reflect a combination of initial conditions and environmental effects.