Time-resolved spectroscopy of the peculiar H alpha variable Be star HD 76534

Abstract

We present time-resolved spectroscopy of the Be star HD 76534, which was observed to have an Ha outburst in 1995, when the line went from photospheric absorption to emission at a level of more than two times the continuum within 2.5 hours. To investigate the short-term behaviour of the spectrum of HD 76534 we have obtained 30 spectra within two hours real-time and searched for variations in the spectrum.Within the levels of statistical significance, no variabilitywas found. Rather than periodic on short time scales, the H behaviour seems to be commonly episodic on longer (> 1 year) time scales, as an assessment of the existing data on theH line and the Hipparcos photometry suggests. HD 76534 underwent only 1 photometric outburst in the 3 year span that the star was monitored by the Hipparcos satellite.