Black holes have only a handful of properties compared to, say, a star -- they have mass, electrical charge, and spin (spin angular momentum). More detail here

Black holes have only a handful of properties compared to, say, a star -- they have mass, electrical charge, and spin (spin angular momentum). More detail here: http://en.wikipedia.org/wiki/Rotating_black_hole#Types_of_black_holes http://en.wikipedia.org/wiki/Rotating_black_hole#Types_of_bl... The reason black holes possess spin is because spin angular momentum is conserved, and the masses that fall into the BH each have spin angular momentum. The black hole's spin angular momentum is therefore the sum (so to speak) of the constituent masses that make it up.