When used this way in the present tense, the hay form of haber is used. 1  Hay que saltar. 2  Hay que conocerlo para comprenderlo. 3  HabrÃ¡ que salir a las dos.
So, even though we cannot actually count the number of stars in the galaxy, we can estimate the number of stars in the galaxy as roughly 100 billion (100,000,000,000). It turns out that there are many more stars with mass less than the mass of the Sun than with mass more than the mass of the Sun. So, it all works out right.
Of the 5,000 to 8,000 stars in the Milky Way visible to the human eye from Earth, one can usually only see about 2,500 at a time. In fact, the few thousand stars we can see of the Milky Way with our naked eye are only about 0.000003% of the 200-400 billion stars that inhabit the spiral! [source]