Every galaxy has a supermassive black holes at the center of it.
But the other weird thing is that there’s other black holes too that aren’t necessarily at the center of galaxies.
Supermassive black holes are collapsed stars a few times the mass of a sun.
At the end of their life, they run out of their fuel and explode.
An event horizon’s point of no return
Black hole’s collapse because gravity squashes them to an infinitely dense point. But nothing can stop their collapse because they’re sufficiently massive.
Even using our strongest telescopes, we don’t know what happens at the middle of a black hole. Because of its immense gravity, they can distort and twist space-time which is the fabric that shapes our universe.
But they collapses to such an extent that light and their surrounding can’t escape. If you fall in its event horizon, then you reach a point that you are getting pulled into the center.
If you fall into an event horizon, you are going to the middle singularity. It’s the ultimate “no escape” that will squash you to an infinitely dense point.
Our sun will be a white dwarf
For 95% of our sun’s life, it burns hydrogen into helium which releases energy. Our sun has a life expectancy of about 10 billion years and it’s currently into 5 billion years of its lifespan.
These types of main sequence stars won’t become a supernova and will collapse into a white dwarf. All lightweight stars like our sun end up as very dense, white dwarf stars.
Because of the Pauli Exclusion Principle, there’s a force that electrons don’t like to be close to each other. But as electrons move closer together, they move faster. This makes a force which holds them together which creates a white dwarf star.
Whereas it’s the same principle for neutron stars. But instead electrons crush into protons and turn into neutrons becoming a neutron star. For example, the crab pulsar in the crab nebula was due to a star’s supernova explosion, which then collapses to form a neutron star.
Anatomy of an Active Black Hole (Infographic)