Issue |
Astron. Astrophys. Suppl. Ser.
Volume 130, Number 3, June II 1998
|
|
---|---|---|
Page(s) | 455 - 464 | |
DOI | https://doi.org/10.1051/aas:1998238 | |
Published online | 15 June 1998 |
An extensive
-photometric survey of southern B and A
type
bright stars *,**
1
Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 104, Santiago 22, Chile
2
Institut für Astronomie der Universität Wien, Türkenschanzstraße 17, A-1180 Wien, Austria
3
CNPq/Laboratório Nacional de Astrofísica, Caixa Postal 21, CEP 37500-000 Itajubá, MG, Brasil
Send offprint request to: H.M. Maitzen, e-mail: MAITZEN@ASTRO.AST.UNIVIE.AC.AT
Received:
31
July
1997
Accepted:
16
January
1998
Photoelectric photometry of 803 southern BS objects in the -system as detection tool for magnetic chemically peculiar (=CP2)
stars has been carried
out and compared to published spectral types. The statistical yield of
such objects detected by both techniques is practically the same. We
show that there are several factors which contaminate the search for
these stars, but this contamination is only of the order of 10%
in both techniques. We find a smooth transition from normal to peculiar
stars.
Our sample exhibits the largest fraction of CP2 stars at their
bluest colour interval, i.e. 10% of all stars in the colour range
or
. No
peculiar stars based on the
-criterion were found
at bluer colours. Towards the red side the fraction of
CP2 stars drops to about 3% for positive values of
or
with red limits roughly corresponding
to normal stars of spectral type A5.
The photometric behaviour of other peculiar stars: Am, HgMn,
δ Del, λ Boo, He abnormal stars, as well as Be/shell
stars and supergiants
shows some slight, but definite deviations from normal stars.
Spectroscopic and visual binaries are not distinguished from normal
stars in their
behaviour.
The results of this work justify larger statistical work (e.g. in open
clusters) employing more time-saving photometric methods (CCD).
Key words: techniques: photometric / stars: chemically peculiar / catalogues
© European Southern Observatory (ESO), 1998