So, what if Equestria's Sun is actually a tiny white dwarf? This one is just a little larger than our Moon, and would be a perfect size to be able to pull around a planet in a tight orbit.

https://www.youtube.com/watch?v=xeE8Amns4WQ

Though, that makes Celestia still exceedingly powerful... she's tossing a star around that's incredibly dense and massive, with an immense magnetic and gravitational field.

She'd be able to bitch-slap Goku!