Program: GN-2020B-Q-212

The stars with B spectral type form a diverse group, that includes not only normal B stars but different sub-groups that present spectroscopic peculiarities. Two of these groups are the Be and B[e] stars. Their peculiarities originate by the presence of a circumstellar envelope of gas and/or dust. Carrying out temporal monitoring of a sample of Be stars, we were surprised to find CO band heads in emission in the medium resolution spectrum of 12 Vul. The presence of CO molecular band emission in Be stars had not been previously reported. We aim to study the CO bandhead structure of the Be star 12 Vul, and for that, we need a higher resolutions spectrum. Modelling the structure of the CO band heads in the region of 2.3 microns, using the code developed by Kraus et al. (2000) and Kraus (2009), will thus provide detailed information on the kinematics at the inner edge/rim of the molecular disk or ring around this star. The detection of CO band emission will be a valuable element to discuss the evolution and physical conditions of the Be star disk since there is no previous report of CO emission in this group of objects.