  We performed the optical spectroscopy of 16 classical Be stars in 11 open
clusters older than 100 Myr. Ours is the first spectroscopic study of classical
Be stars in open clusters older than 100 Myr. We found that the H alpha
emission strength of most of the stars is less than 40 Angstrom, in agreement
with previous studies. Our analysis further suggests that one of the stars,
KW97 35 12, might be a weak H alpha emitter in nature, showing H alpha
equivalent width of negative 0.5 Angstrom. Interestingly, we also found that
the newly detected classical Be star LS III 47 37b might be a component of the
possible visual binary system LS III 47 37, where the other companion is also a
classical Be star. Hence, the present study indicates the possible detection of
a binary Be system. Moreover, it is observed that all 16 stars exhibit a lesser
number of emission lines compared to classical Be stars younger than 100 Myr.
Furthermore, the spectral type distribution analysis of B type and classical Be
stars for the selected clusters points out that the existence of CBe stars can
depend on the spectral type distribution of B type stars present in these
clusters.
