Could there be intelligent aliens 500 years advanced than us? Some where in the galaxy?

[ProfessorGAC]

55. I Say Yes

And it is likely to be far more than 500 years more advanced.
There's a few billion stable stars in the Milky Way that are as much as a billion years older than the sun.
So, sure.
That doesn't mean, however, I am sold on extraterrestrial visitation.
My take is that a highly advanced civilization that learned long ago how to break the light barrier would have the tech to stealthily observe a planet from a few hundred thousand kilometers away.
And, I'd expect their imaging tech to allow for highly detailed analysis from that distance.
And since they'd only be around a light-second out, they could monitor broadcasts, use algorithms to translate and do anthropology about earth at a great distance.
But, is it possible? Sure. In fact, no matter how we apply the Drake equation, we don't come to zero probability.
So, I say it's likely.