Issue |
Astron. Astrophys. Suppl. Ser.
Volume 119, Number 2, October II 1996
|
|
---|---|---|
Page(s) | 271 - 279 | |
DOI | https://doi.org/10.1051/aas:1996244 | |
Published online | 15 October 1996 |
Be stars in open clusters.
I. uvby
photometry*
1
Departamento de Astronomía, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
2
Departamento de Ingeniería de Sistemas y Comunicaciones, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
3
Centro de Cálculo, Universidad Politécnica de Valencia, Camino de Vera 14, 46022 Valencia, Spain
4
Círculo Astronómico del Mediterráneo, Fundación Cultural de la Caja de Ahorros del Mediterráneo, Apdo. 616, 03080 Alicante, Spain
Corresponding author: Send offprint request to: J. Fabregat, e-mail: fabregat@evalvx.ific.uv.es
Received:
21
January
1996
Accepted:
5
March
1996
We present uvby
β photometry for Be stars in eight open clusters and two OB
associations. It is shown that Be stars occupy anomalous positions in the
photometric diagrams, which can be explained in terms of
the circumstellar continuum radiation contribution to the photometric
indices.
In the - MV plane Be stars appear redder than the non emission B stars,
due to the additional reddening caused by the hydrogen free-bound and
free-free recombination in the circumstellar envelope. In the c0 - MV plane
the earlier Be stars present lower c0 values than absorption-line B stars,
which
is caused by emission in the Balmer discontinuity, while the later Be stars
deviate towards higher c0 values, indicating absorption in the
Balmer discontinuity of circumstellar origin.
Key words: techniques: photometric / stars: emission-line, Be / open clusters and associations: general
Based on observations made with the Jacobus Kaptein Telescope operated on the island of La Palma by the Royal Greenwich Observatory, in the spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, and with the 1.5 m. telescope of the Instituto Geográfico Nacional, jointly operated by the Instituto Geográfico Nacional and the Consejo Superior de Investigaciones Científicas through the Instituto de Astrofísica de Andalucía, at the Calar Alto Observatory
© European Southern Observatory (ESO), 1996