The VLT-FLAMES survey of massive stars: atmospheric parameters and rotational velocity distributions for B-type stars in the Magellanic Clouds

Understand

We provide atmospheric parameters and rotational velocities of a large sample (~400) of O- and early B-type stars, analysed in a homogeneous and consistent manner, for use in constraining theoretical models.

• Comparison of the rotational velocities with evolutionary tracks suggest that the end of core hydrogen burning occurs later than currently predicted.
• We also show that the large number of the luminous blue supergiants observed in the fields are unlikely to have directly evolved from main-sequence massive O-type stars as neither their low rotational velocities or position on the H-R diagram are predicted.
• We suggest that blue-loops or mass-transfer binary systems may populate the blue supergiant regime.