Editing Quark star (section)

==Background==
{{Unreferenced section|date=March 2024}} 
Some [[star#Massive stars|massive stars]] collapse to form [[neutron stars]] at the end of their [[stellar life cycle|life cycle]], as has been both observed and explained theoretically. Under the extreme temperatures and pressures inside neutron stars, the neutrons are normally kept apart by a [[Neutron degeneracy|degeneracy pressure]], stabilizing the star and hindering further gravitational collapse.<ref>{{Cite web |last=Seife |first=Charles |title=Quark Stars Get Real |url=https://www.science.org/content/article/quark-stars-get-real |website=Science.org}}</ref> However, it is hypothesized that under even more extreme temperature and pressure, the degeneracy pressure of the neutrons is overcome, and the [[neutrons]] are forced to merge and dissolve into their constituent quarks, creating an ultra-dense [[Phase (matter)|phase]] of [[quark matter]] based on densely packed quarks. In this state, a new equilibrium is supposed to emerge, as a new degeneracy pressure between the quarks, as well as repulsive [[electromagnetic force]]s, will occur and hinder [[black hole|total gravitational collapse]].

If these ideas are correct, quark stars might occur, and be observable, somewhere in the universe. Such a scenario is seen as scientifically plausible, but has not been proven observationally or experimentally; the very extreme conditions needed for stabilizing quark matter cannot be created in any laboratory and has not been observed directly in nature. The stability of quark matter, and hence the existence of quark stars, is for these reasons among the [[List of unsolved problems in physics|unsolved problems in physics]].

If quark stars can form, then the most likely place to find quark star matter would be inside [[neutron star]]s that exceed the internal pressure needed for [[degenerate matter|quark degeneracy]] – the point at which [[neutron]]s break down into a form of dense quark matter. They could also form if a [[massive star]] [[core collapse supernova|collapses]] at the end of its life, provided that it is possible for a star to be large enough to collapse beyond a neutron star but not large enough to form a [[black hole]].

If they exist, quark stars would resemble and be easily mistaken for neutron stars: they would form in the death of a massive star in a [[Type II supernova]], be extremely dense and small, and possess a very high gravitational field. They would also lack some features of neutron stars, unless they also contained a shell of neutron matter, because free quarks are not expected to have properties matching degenerate neutron matter. For example, they might be radio-silent, or have atypical sizes, electromagnetic fields, or surface temperatures, compared to neutron stars.