Astron. Astrophys. 343, 237-240 (1999)

A constraint on the angular momentum evolution of Be stars

I.A. Steele

Astrophysics Research Institute, Liverpool John Moores University, Egerton Wharf, Birkenhead, L41 1LD, UK

Received 29 September 1998 / Accepted 30 October 1998

Abstract

The Be star sample of Steele et al. (1998) has a distribution of 's that is luminosity dependant, with giants having lower projected rotational velocities than dwarfs. We show that this effect can be understood simply in terms of angular momentum conservation during the evolution from dwarf to giant. Any decretion disk or other angular momentum losing mechanism for such objects must cause a loss of no more than 15% of the stellar angular momentum over the Be phase lifetime.

Key words: stars: rotation stars: emission-line, Be

Send offprint requests to: I.A. Steele

Correspondence to: ias@astro.livjm.ac.uk

This article contains no SIMBAD objects.

Contents

• 1. Introduction
• 2. Distribution functions
  • 2.1. Description of the sample
  • 2.2. and distributions
  • 2.3. Angular momentum distribution
• 3. Angular momentum evolution
• 4. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: March 1, 1999
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