Issue |
Astron. Astrophys. Suppl. Ser.
Volume 128, Number 1, February II 1998
|
|
---|---|---|
Page(s) | 117 - 129 | |
DOI | https://doi.org/10.1051/aas:1998129 | |
Published online | 15 February 1998 |
Hipparcos photometry of 24 variable massive stars (α Cygni variables)
1
Royal Greenwich Observatory, Madingley Road, Cambridge, CB3 0EZ, UK
2
Leiden Observatory, Postbus 9513, 2300 RA Leiden, The Netherlands
Send offprint request to: F. van Leeuwen
Received:
28
May
1997
Accepted:
17
June
1997
The photometric variability of 24 α Cyg variables, i.e.
variable super–and hypergiants, observed by the Hipparcos satellite
is described. Three of the selected stars are situated in the SMC,
12 in the LMC and the remaining 9 in the Galactic plane. Four of them
are hot S Dor–type variables, or LBVs (luminous blue variables) and
two are possible members of this class. Light curves are presented for
all stars. For five stars, among which one LBV, the variability was discovered
from the Hipparcos photometric data. Results of period searches are presented
and, when relevant, folded light curves are shown. The linear ephemeris of two
variables was revised.
For most of the program stars the Hipparcos magnitude scale (Hp) differs
from the V of the UBV system by . For all variables temperatures
and Mbol are given. Galactic foreground reddening for the objects in
the Magellanic Clouds are given based on IRAS maps.
Key words: stars: variables / stars: supergiants / techniques: photometric / magellanic clouds
© European Southern Observatory (ESO), 1998