Evolution of Galactic Field be Stars

Original · EN

Galactic field Be stars were studied by taking into account the effects induced by the fast rotation on their fundamental parameters. Fractional ages τ/τ_ MS (τ_ MS = time spent in the MS) against stellar mass reveal that: a) Be stars spread over the whole interval 0<τ/τ_ MS<1; b) the Be phenomenon in massive stars (M>12M_) is present at smaller age ratios than for less massive stars (M<12M_); c) there is a lack of Be stars with M<7M_ in the first half of the MS. Low mass fast rotators (M<7M_), called Bn stars, could be "becoming" Be stars.