Be stars (GCAS variables) are non super giant B stars that show or have shown at least once emission lines in their spectra. Halpha is usually the first line to appear so there is, for more than ten years now, a specific pro/am program to monitor the spectra of those stars. Herbig Ae/Be have been added to the program few years ago.
Spectra are archived in BeSS database:
There are almost 21000 observations archived, more than 144000 'orders' - half of them by amateurs. We are approaching the 20000 'orders' for this year of 2017 alone.
This very active project has a monthly newsletter edited by Valérie Desnoux - see attached for the last two issues. It shows almost 20 active observers and lot of stars worth monitoring with evolution at different time scales.
See also the list of publications using BeSS spectra (not updated so here is more now!) on the BeSS web site (click 'Publications' on the left menu).
A hot topic recently has been V442 And which came into outburst in august. The emission is now very faint/gone and this event has been closely monitored by several observers - its evolution is showing some interesting features.
Anyway, I just wanted to let you know about the newsletter if you didn't know about it. If you want to join the project, do not hesitate it is very open and a team of validators ensure the quality of all spectra and help you if you are unsure of your first spectra.