In the first video, the Mound Builders belief (also similar to Egyptian) was that the stars are souls. They are souls making their way through their tests, and possibly making their way through the Path of Souls on a journey to their eternal resting place (unless they fail the tests of course). Assuming I followed that video correctly.

I am not sure why celebrities would call themselves "stars" though? Unless they are individuals that have previously failed their tests and been re-incarnated? That still doesn't really explain why they would call themselves "stars" or "souls" though.