How to Form a Star

The size of the clumps that tend to form does depend on the metallicity. If your clumps are too small, you just get a bunch of Jupiter's. You don't get real stars. The rate of star formation in galaxies like ours is a lot less than it was a billion years ago. And actually our galaxy, like the Milky Way and Andromeda, we think are both starting to quench. They're forming maybe seven stars per year.