Astronomy is the scientific study of the heavens and all that is therein. It is not to be confused with astrology which lacks any kind of scientific basis and encompasses the belief that heavenly bodies influence human lives.
There are many millions of stars in the sky but we can only see a few thosand of them  with the naked eye. In whole  heavens, fewer than 6,000 stars are bright enough to be visable and at any one time less than 2,500 stars are visable above the horizon.

Astronomers are making new discoveris all the time and finding that the deeper they probe into the universe, the more mysterious it becomes. They seem continually to be finding answers for which they don't even have questions.