Thanks for the answers guys.
I guess from what I've heard that we can safely assume that these are stars the Enterprise is passing. I do think it's a bit odd that this was never explained at any point of the show though. Maybe they did that to leave room for interpretation?
Don't let some of these knuckle head responders get you down. It was a good question. But looking at some of the responces, you can see why some TREK FANS are probably still living at home with mom/dad, unemployed..and still virgins at the age of 50.