Kip S Thorne's "Black Holes & Time Warps", 1994 paperback, p.415, Box 12.1: ... The absolute horizon is just a point when created, but it then expands smoothly, like a balloon being blown up, ...
When two neutron stars or black-holes come closer and closer, their angular velocity increases with decrease of distance and they start to revolve around a constant center with high relativistic ...
A supernova's Ni/Fe core remnant with mass exceeding about three solar masses would result in a black hole. Although the core's temperature was in the ~1E10K range, the black hole temperature based on ...