A quasi-star, or also known as a black hole star, is a type of hypothetical star object that is very large and very luminous. This star may have appeared in the early history of the universe and has a black hole at its core. They have a temperature of 4000 Kelvin, but they can be much larger than hypergiants and supergiants than estimated radius of 10 billion kilometres or 7,180, 7 times that of the sun. The mass of this quasi-star is estimated to be 10,000 times the mass of the sun. Unlike modern stars whose energy is generated by nuclear fusion in their cores, a quasi-stars energy would come from matter falling into the black hole at its core. They fall when the core of a massive protostar collapses into a black hole during its formation. After its formation, it would continuously radiate large amounts of energy from additional the tip of info.