Editing Compact object (section)

{{Short description|Classification in astronomy}}
{{For|the categorical notion in mathematics|Compact object (mathematics)}}
{{Distinguish|dwarf star|central compact object}}
In [[astronomy]], the term '''compact object''' (or '''compact star''') refers collectively to [[white dwarf]]s, [[neutron star]]s, and [[black hole]]s. It could also include [[exotic star]]s if such hypothetical, dense bodies are confirmed to exist. All compact objects have a high [[mass]] relative to their radius, giving them a very high [[density]], compared to ordinary [[atom]]ic [[matter]].

Compact objects are often the endpoints of [[stellar evolution]] and, in this respect, are also called '''stellar remnants'''. They can also be called '''dead stars''' in public communications. The state and type of a stellar remnant depends primarily on the mass of the star that it formed from. The ambiguous term ''compact object'' is often used when the exact nature of the star is not known, but evidence suggests that it has a very small [[radius]] compared to ordinary [[stars]]. A compact object that is not a black hole may be called a '''degenerate star'''.

In June 2020, astronomers reported narrowing down the source of [[Fast radio burst|Fast Radio Bursts]] (FRBs), which may now plausibly include "compact-object mergers and [[magnetar]]s arising from normal core collapse [[supernova]]e".<ref name="SA-20200601">{{cite news |last=Starr |first=Michelle  |title=Astronomers Just Narrowed Down The Source of Those Powerful Radio Signals From Space |url=https://www.sciencealert.com/we-re-starting-to-figure-out-where-fast-radio-bursts-come-from |date=1 June 2020 |work=ScienceAlert.com |access-date=2 June 2020 }}</ref><ref name="AJL-20200601">{{cite journal |author=Bhandan, Shivani |title=The Host Galaxies and Progenitors of Fast Radio Bursts Localized with the Australian Square Kilometre Array Pathfinder |date=1 June 2020 |journal=[[The Astrophysical Journal Letters]] |volume=895 |number=2 |pages=L37 |doi=10.3847/2041-8213/ab672e |arxiv=2005.13160 |bibcode=2020ApJ...895L..37B |s2cid=218900539 |doi-access=free }}</ref>