Why H alpha?

Forums Spectroscopy Why H alpha? Why H alpha?

Dr Andrew Smith

I think the simple answer is yes. Not only the atmosphere but also any surrounding shell or ring of gas which is normally mostly hydrogen. It is not always the case but there has been a strong focus on Be stars where the hydrogen alpha line has been the main focus as it shows the most variation.

Other lines are important for radial velocity measurement and in spectral classes where hydrogen lines are very weak or absent.

Regards Andrew