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Astron. Astrophys. Suppl. Ser.
Volume 119, Number 2, October_II 1996
Page(s) 271 - 279
Be stars in open clusters. I. uvby photometry DOI: 10.1051/aas:1996244

Astronomy and Astrophysics Supplement Series, Vol. 119, October II 1996, 271-279

Be stars in open clusters. gif I. uvby photometry

J. Fabregat , J.M. Torrejón , P. Reig , G. Bernabeu , J. Busquets , A. Marco and V. Reglero
Send offprint requests to: J. Fabregat (fabregat@evalvx.ific.uv. es)

Departamento de Astronomía, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
Departamento de Ingeniería de Sistemas y Comunicaciones, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
Centro de Cálculo, Universidad Politécnica de Valencia, Camino de Vera 14, 46022 Valencia, Spain
Círculo Astronómico del Mediterráneo, Fundación Cultural de la Caja de Ahorros del Mediterráneo, Apdo. 616, 03080 Alicante, Spain

Received January 21; accepted March 5, 1996


We present uvby 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 - 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 - plane the earlier Be stars present lower values than absorption-line B stars, which is caused by emission in the Balmer discontinuity, while the later Be stars deviate towards higher values, indicating absorption in the Balmer discontinuity of circumstellar origin.

Key words: techniques: photometric --- stars: emission-line, Be --- open clusters and associations: general

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