weird question for anyone with the relevant knowledge, would 25 ronna-Reagans in one place behave differently than our sun? I know that mass would be mostly oxygen, but at that scale does it matter?
By mass, the sun is 71% Hydrogen and 27.1% Helium, the last 1.9% or so being heavier elements (much of that being oxygen.
I’m no expert, but I suspect a mass of 25 ronna-Reagans would not make a very good star. I imagine it might collapse into a dense Oxygen and Carbon rich sphere, and in that environment various chemical reactions might turn it into some other kind of material.
But maybe I’m way off.
Upping the mass to the sun size would cause some interesting additional wrinkles because now we're talking about being large enough to have "problems" with the pressures in the middle being sufficient to start causing atoms to squish together, but it would take an astronomer to be clear on what happens next. My gut and layman's understanding says you might get a pretty big boom in a couple hundred thousand years or so, because you'd basically be building a sun that would be fairly far along its fuel consumption cycle.