G'Day Rolf. Great start!
There's lots of reference spectra around, but you might need a program like VSpec to view them, however, search this forum and I'm sure you'll find spectra of both Betelgeuse and Sirius in JPG format for comparison. I'm sure I've posted spectra of both of these and so have others probably.
A couple of free programs I suggest you get so can process them and keep developing are IRIS, and VSpec.
You can hten cut down the noise by stacking multiple images, preprocess them in Iris and convert them to graphs and analyse them with VSpec.
Welcome aboard!
Al.