Bibcode
Telting, J. H.; Schrijvers, C.; Ilyin, I. V.; Uytterhoeven, K.; De Ridder, J.; Aerts, C.; Henrichs, H. F.
Bibliographical reference
Astronomy and Astrophysics, Volume 452, Issue 3, June IV 2006, pp.945-953
Advertised on:
6
2006
Journal
Citations
48
Refereed citations
42
Description
We present a study of absorption line-profile variations in early-B type
near-main-sequence stars without emission lines. We have surveyed a
total of 171 bright stars using the Nordic Optical Telescope (NOTSA),
William Herschel Telescope (ING) and Coudé Auxiliary Telescope
(ESO). Our sample contains 75% of all O9.5-B2.5 III-V non-emission-line
stars brighter than 5.5 mag. We obtained high signal-to-noise,
high-resolution spectra of the SiIII λ4560 triplet - for 125
stars of our sample we obtained more than one spectrum - and examined
these for pulsational-like line-profile variations and/or structure. We
conclude that about half of our sample stars show evidence for
line-profile variations (LPV). We find evidence for LPV in about 65% of
our sample stars brighter than V=5.5. For stars with rotational
broadening V sin i ˜100 km s-1, we find evidence for
LPV in about 75% of the cases. We argue that it is likely that these LPV
are of pulsational origin, and that hence more than half of the
solar-neighbourhood O9.5-B2.5 III-V stars is pulsating in modes that can
be detected with high-resolution spectroscopy. We detected LPV in 64
stars previously unknown to be pulsators, and label these stars as new
β Cep candidates. We conclude that there is no obvious difference
in incidence of (pulsational) LPV for early-B type near-main-sequence
stars in binaries or in OB associations, with respect to single field
stars.