What is a quasistar?

Most of the stars in today’s universe are of the third generation. The first generation stars that lived at the dawn of the universe are the largest the universe has ever seen or will ever see again.

In the early and dense universe, black holes could not evaporate although small, because they were surrounded by a uniform amount of matter that constantly fed them.

The collapse of the surrounding material releases a lot of energy, but there is just so much matter around the black hole that the star keeps staying compact.

So instead of pressure from nuclear fusion reactions, there is pressure from the energy released by matter falling into the black hole.

This is how quasistars form: extremely massive stars, much larger than those that can occur now, as bright as a small galaxy, and with a black hole in their core.

Over time, the layers of the star will eventually be swept away or engulfed by the central black hole, which is ultimately the only thing that is left.

The resulting black holes had an insane mass and probably then played an important role in the formation of galaxies, becoming the titans we see at their core today.