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Issue A&A Volume 393, Number 3, October III 2002 Page(s) 887 - 896 Section Formation, structure and evolution of stars DOI 10.1051/0004-6361:20020916

A&A 393, 887-896 (2002)
DOI: 10.1051/0004-6361:20020916

On Be star candidates and possible blue pre-main sequence objects in the Small Magellanic Cloud

R. E. Mennickent¹, G. Pietrzynski^{1, 2}, W. Gieren¹ and O. Szewczyk<sup>2

1</sup>  Universidad de Concepción, Departamento de Física, Casilla 160-C, Concepción, Chile
    e-mail: pietrzyn@hubble.cfm.udec.cl, wgieren@coma.cfm.udec.cl
²  Warsaw University Observatory, Al. Ujazdowskie 4,00-478, Warsaw, Poland
    e-mail: szewczyk@astrouw.edu.pl

(Received 24 April 2002 / Accepted 17 June 2002)

Abstract
Recently the OGLE experiment has provided accurate light curves and colours for about 2 millions stars in the Small Magellanic Cloud. We have examined this database for its content of Be stars, applying some selection criteria, and we have found a sample of ~1000 candidates. Some of these stars show beautiful light curves with amazing variations never observed in any Galactic variable. We find outbursts in 13% of the sample (type-1 stars), high and low states in 15%, periodic variations in 7%, and the usual variations seen in Galactic Be stars in 65% of the cases. The Galactic counterparts of type-1 objects could be the outbursting Be stars found by Hubert & Floquet ([CITE]) after the analysis of Hipparcos photometry. We discuss the possibility that type-1 stars could correspond to Be stars with accreting white dwarf companions or alternatively, blue pre-main sequence stars surrounded by thermally unstable accretion disks. We provide coordinates and basic photometric information for these stars and some examples of light curves.

Key words: stars: pre-main sequence -- stars: emission-line, Be -- stars: variable: general -- X-rays: binaries -- galaxies: individual: SMC

Offprint request: R. E. Mennickent, rmennick@stars.cfm.udec.cl

© ESO 2002

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