Can you watch the stars when the sun is up?

No, because you shouldn't look at the sun! Your eyes will light on fogo and burn if you do that.

..That's just one star, though. But seriously, it depends where the sun is in the sky. When it's rising/setting, maybe. When it's up in the sky, middle of the day, I doubt it. You are able to sometimes see the moon, though!

The stars on TV/Movies yes.

Stars in the sky no.

Yes.