It can't be a brown dwarf, as those are main sequence stars like our sun, and Hala's sun is basically dehydrated. It is likely, at that point, a binary white dwarf star, or on its way to become one.
Note: Stars die after exhausting their hydrogen source and only having helium left. They are expected to be about 60-70% hydrogen by mass. So Captain Marvel (should have by science) essentially replenished the star's energy source by restoring the lost hydrogen.
Also, tier 4 would probably have interesting scaling, considering Dar Benn used the same weapon as Ronan. For the eventual tier 2 feat, the quantum bangles are incapable of doing so without the power of the Marvel trio + Universal Weapon amp