Black Holes

1. If there is sufficient mass to overcome all degenerate pressure, hydrostatic equilibrium will continue to regulate the stars size and fusion rate. 
2. Since there is no end to its compression it compressed into a single point  called a “Singularity”, which is the center of a black hole.
3. Black holes are formed when the remaining mass is around 4 or 5 times the  size of the Sun. 
1. As very large stars advance to burn silicon, an iron core will begin to form where no fusion takes place. 
2. Since there is no fusion in this core, there is no pressure to counteract gravity. 
3. When the iron core exceeds 1.4 Solar masses, it will collapse. 
4. This core collapse takes place very fast (about 1mSec), so the outer layers fall inward to the core and bounce off in an explosion called a “supernova”.