Study of classical Be stars in open clusters older than 100 Myr

Abstract

We performed the slitless spectroscopic survey to identify classical Be (CBe) stars in open clusters older than 100 Myr. Observing a sample of 71 open clusters, we identified 13 CBe stars in 11 open clusters, one of, which (TYC 2679-432-1) is a new detection. The 13 CBe stars show both Ha in emission and IR excess, which confirm that they possess gaseous circumstellar discs. Two more CBe stars are found to exhibit Ha in absorption for the first time, indicating that might be passing through disc-less episode presently. The spectral-type estimation is done for all these 15 stars and it is noticed that they belong to B0.5–B8 type. Moreover, we found that the distribution of our sample is peaking near late B-types as expected.