A new spectacular discovery. The black hole must be satisfied after such a good meal.
This is what the experiments of Virgo and Ligo seem to suggest. As so often happens in science, more research is required before we can be certain! Black holes and neutron stars are both forming in the Universe, after a supernova explosion. The difference is in the mass of the collapsing core of the dying star. In particular, a black hole always satisfies the Schwarzschild equation, which means that for a given radius there exists a critical mass. A neutron star is also an ultra-compressed form of matter, to the extend that the electrons are forced to move away from their nuclei, and hence the nuclei gain a lot of free space, forming an extremely dense object. A neutron star has 2 or 3 times the mass of the Sun, but its radius is only about 20 km. A black hole can be described more accurately as an extremely compact object, of an unknown state of matter, rather than as a point mass of infinite density. No known force in nature can resist the collapse of matter under a strong enough gravity! Perhaps, we don't understand enough about quantum gravity and what are the truly smallest particles of matter in the Universe, as well as their behaviour when they are forced to go very close to each other, under such a strong gravity. When a black hole collides with a star, this usually happens after the pair follows a spiral orbit, or after dancing a deadly cosmic tango that may last thousands of years.