(I'm astrophysicist Neil deGrasse Tyson.) Some with billions, others with trilions of stars, these are the fundamental building blocks of visble matter in the universe; they come in many varieties including spiral, irregular & elliptical
[DOC] [TLE] Death by Black Hole and Other Cosmic Quandaries - Scribd [PAR] Neil deGrasse Tyson has mined his columns from Natural History magazine for 
.... Others in this role include Princeton Astrophysics Professors Bruce Draine.