Is this in any sense hydrogen being converted to photons? Photons are massless, but… the mass of the elements in the star are converted to pure energy?
In a way yes. It’s a byproduct of fusion IIRC. One way to look at it is to examine the atomic weights of hydrogen and helium and the subatomic particles. They don’t exactly add up. So where is the missing mass? This was a big question until we discovered the even smaller particles that made up electrons and protons. I recommend the book How to Make an Apple Pie from Scratch for a good read for laymen on particle physics.
