出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Some indirect observations, as the high fraction of Be stars†at low metallicity, or the necessity for
massive stars to be important sources of primary nitrogen, seem to indicate that very metal poor
stars were fast rotators. As a consequence of this fast rotation, these stars, contrarily to current
wisdom, might lose large amounts of mass during their lifetime. In this paper, we review various
mechanisms triggered by rotation which may induce strong mass loss at very low metallicity. The
most efficient process comes from surface enrichments in CNO elements which then drive mass
loss by stellar winds. Due to this process, a fast rotating 60 M
⊙
with metallicities in the range
of Z = 10−8 and 10−5, can lose between 30 and 55% of its initial mass. This rotationally wind
ejected material participates to the chemical evolution of the interstellar medium, enriching it
exclusively in H- and He-burning products. In particular, metal poor fast rotating stars may play
a key role for explaining the origin of the peculiar abundance pattern observed at the surface of
the extremely metal-poor C-rich stars, for explaining the chemical inhomogeneities observed in
globular clusters, and the presence of stars in w Cen with a very high helium content .
