Letter to the Editor

A spectroscopic search for variability of Be stars in the SMC^*

¹ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85 748 Garching bei München, Germany
² Astronomical Institute, Academy of Sciences, 251 65 Ondřejov, Czech Republic
³ European Southern Observatory, Casilla 19 001, Santiago 19, Chile

Corresponding author: D. Baade, dbaade@eso.org

Received: 6 November 2001
Accepted: 14 January 2002

Abstract

Two low- early-type Be stars in the area of the young cluster NGC 330 in the Small Magellanic Cloud (SMC) were monitored with the VLT and the UVES echelle spectrograph during 8 consecutive nights. Exposure times between 45 and 60 min yielded a signal-to-noise ratio of about 80. The temporal variance in the line profiles does not significantly differ from the one of the continuum in both sets of about two dozen spectra. Four more stars were observed only once or twice; their line profiles, too, were not asymmetric. This is in marked contrast to the Galaxy, where short-term line profile variability would normally have been detected with high probability in at least one out of any two randomly selected Be stars of early spectral sub-class and low v sin i. Some possible repercussions on the understanding of the Be phenomenon are briefly discussed.