Spectral obervations of flare stars TZ ARI and ROSS 867

Abstract

The results of spectral observations of flare stars TZ Ari and Ross 867B are presented. Observations have been carried out by the 2.6m telescope of Byurakan Astrophysical Observatory in 1999, 2001 and 2018. The spectral cameras "ByuFOSC" and "SCORPIO" were used during the observations. A strong change of emission lines detected on TZ Ari in 2018, while at the same time the brightness changes of the star in all measured spectral ranges are within the framework of measurement errors. Slight variations of brightness and EWHα are detected in quiescent state of star during the observations in 1999. A strong flare of Ross 867B were observed, with a duration of more than 20min. In this case if EWHα shows strong change, when its maximum value corresponds to the photometric maximum of are, at the same time EWHα shows decrease, similar to that, observed earlier during the flares of stars EV Lac, HU Del, CM Dra and WX UMa.