Do you have any proof for this, or is it nothing but speculation on your part. The "power of a million exploding suns" thing is more a a quantifier of his power, not a descriptor.
However a character that was powered by a million suns fought agaisnt Supes and he absorbed his energy and directed it back to him. At this point, there is more to support supes being powered up by sentry then the latter.
But that character wasn't Sentry, as far as I'm aware Kal El and Bob have never encountered each other. Sentry isn't powered by a million suns, he has the equivalent powered of them. I'm not buying Supes being powered up by Bob at all.
Gender: Male Location: Drinking gasoline. Pissing napalm.
Don't listen to Galen's crap. Sentry does not produce yellow solar energy. He can, however, draw power from the sun (like Superman can.)
The proof for this is that, basically, not one of Earth's scientists know the limits of Sentry's power or exactly what empowers him. Even Ultron could not figure it out. So it can't be your basic, standard yellow sunlight.
Except for the fact that there isn't anything suggesting Sentry would power him. Everything we've learned about Goldilocks's power is that it can't be classified as something as simple as yellow solar, and nothing at all has described it as such in any comic I've read featuring him. I'd say the team has an edge here but its certainly not because Sentry powers up Superman, as nothing suggests he would.