Quasi-star
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
The core of an extremely massive protostar would collapse into a black hole after reaching a certain mass, and normally the outer layers of the star would be blown away by the resulting supernova. However, because this hypothetical star is so large and dense with material, the outer layers would remain, and the black hole would serve as the core of this new quasi-star.
Material from the star would fall inwards into the black hole, which would generate an enormous amount of energy, creating an outward push. But the intense gravity of the star and black hole would pull inwards with equal force, which would let the star keep its shape. For this to happen, a quasi-star would need to be as large as 10 billion kilometers in diameter, which is 7,187 times the diameter of the Sun.[1] This would dwarf VY Canis Majoris and Stephenson 2-18 in size, both of which are some of the largest known stars today. If the Sun were replaced by a typical quasi-star, it would extend beyond the orbit of Neptune, the furthest planet in the solar system. The surface of a quasi-star would be incredibly hot, around 9,700 °C, and it would be as bright as a small galaxy.
Due to their turbulent nature, the lifetime of a quasi-star would be fairly short, about 7 million years (compared to 10 billion years for a star like the Sun). Once the material of the quasi-star is exhausted, a fairly large black hole would be left behind, and it is hypothesized that these black holes are the ancestors of modern supermassive black holes.[2]
Quasi-star Media
Size comparison of a hypothetical quasi-star to some of the largest known stars.
A quasi-star rendered with Celestia
Related pages
References
- ↑ Abramowicz, Marek (August 1982). "Twinkle, twinkle quasi star…". Nature. 298 (5877): 789–790. Bibcode:1982Natur.298..789A. doi:10.1038/298789a0. ISSN 0028-0836. S2CID 45589556.
- ↑ Schleicher, Dominik R. G.; Palla, Francesco; Ferrara, Andrea; Galli, Daniele; Latif, Muhammad (2013-10-01). "Massive black hole factories: Supermassive and quasi-star formation in primordial halos". Astronomy and Astrophysics. 558: A59. arXiv:1305.5923. Bibcode:2013A&A...558A..59S. doi:10.1051/0004-6361/201321949. ISSN 0004-6361. S2CID 119197147.