Title of article :
Where do Be stars stand in the picture of rotational mixing?
Author/Authors :
Paul R. Dunstall، نويسنده , , Ines Brott، نويسنده , , Philip L. Dufton، نويسنده , , Chris J. Evans، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2010
Abstract :
Atmospheric parameters and photospheric abundances have been estimated for 60 Be-type stars located in 4 fields over the Magellanic Clouds. Particular attention has been given to the absolute nitrogen abundances to test theories of rotational mixing, an important factor in the evolutionary status of B-type stars,Hunter et al. (2008). The analysis used the non-LTE atmospheric code TLUSTY and required the implementation of a procedure to compensate for possible contamination due to the presence of a circumstellar disc. Through comparison with evolutionary models of fast rotating B-type stars and projected rotational velocity distributions our results support the theory that Be-type stars are typically faster rotators than B stars, but the measured nitrogen enhancements appear to be significantly less than expected for Be stars rotating with velocities greater than 70% of their critical velocity.
Keywords :
Be , stars: atmospheres , stars: evolution , stars: abundances , stars: rotation , (galaxies:) Magellanic Clouds , Stars: emission-line
Journal title :
Proceedings of the International Astronomical Union
Journal title :
Proceedings of the International Astronomical Union