What is Quasi-star?
[[File:Quasi-star_size_comparison.png|thumb|261x261px|The size comparison of a Quasi-star with other stars.]] A '''quasi-star''', also known as '''black hole star''', is a hypothetical type of [[star]] believed to have existed in the beginning of the [[universe]] when most of the existing material was [[hydrogen]] and [[helium]]. Instead of a normal [[nuclear fusion]] core, the core of a quasi-star would be a [[black hole]]. == Formation and properties == Quasi-stars are [[star]]s that were so massive that while they were still alive, their cores became a [[black hole]]. But, the quasi-star didn't go [[supernova]] like in normal stars today. The star was so big that the supernova happening inside the star didn't destroy it. These quasi-stars might have been made in [[dark matter|dark matter halos]]. The gravity of these dark matter halos brought in a lot of gas, which created very big stars. Normally in stars today, [[nuclear fusion]] stops the star's gravity from crushing it. But in quasi-stars, the black hole inside causes matter from the star to move around it. This releases a lot of [[energy]] and stops the star's gravity from crushing the star. Quasi-stars lived for about 7 million years. The black hole at the center of the star could grow up to 1,000 to 10,000 solar masses. If quasi-stars existed the black holes they created could have become the [[supermassive black hole]]s we see at the center of most [[Galaxy|galaxies]], including our own Milky Way.<ref>{{Cite journal|last1=Schleicher|first1=Dominik R. G.|last2=Palla|first2=Francesco|last3=Ferrara|first3=Andrea|last4=Galli|first4=Daniele|last5=Latif|first5=Muhammad|date=2013-10-01|title=Massive black hole factories: Supermassive and quasi-star formation in primordial halos|url=http://adsabs.harvard.edu/abs/2013A%26A...558A..59S|journal=Astronomy and Astrophysics|volume=558|pages=A59|doi=10.1051/0004-6361/201321949|arxiv=1305.5923|bibcode=2013A&A...558A..59S|s2cid=119197147|issn=0004-6361}}</ref> Quasi-stars were very very very big, as big as our sol