Editing X-ray binary (section)

{{Short description|Class of binary stars}}
[[Image:Accretion disk.jpg|300px|thumb|Artist's impression of an X-ray Binary]]

'''X-ray binaries''' are a class of [[binary star]]s that are luminous in [[X-ray]]s. 
The X-rays are produced by matter falling from one component, called the ''donor'' (usually a relatively common [[main sequence]] [[star]]), to the other component, called the ''accretor'', which can be a [[white dwarf]], [[neutron star]] or [[black hole]]. 
The infalling matter releases [[gravitational energy|gravitational potential energy]], up to 30 percent of its rest mass, as X-rays.  (Hydrogen [[nuclear fusion|fusion]] releases only about 0.7 percent of rest mass.)  The lifetime and the mass-transfer rate in an X-ray binary depends on the evolutionary status of the donor star, the mass ratio between the stellar components, and their orbital separation.<ref name=Tauris>{{cite book
 |first1=Thomas M. |last1=Tauris  |first2=Ed |last2=van den Heuvel
 |title=Compact Stellar X-ray Sources |chapter=Chapter 16: Formation and evolution of compact stellar X-ray sources
 |bibcode=2006csxs.book..623T
 |volume=39  |editor1-first=Walter |editor1-last=Lewin  |editor2-first=Michiel |editor2-last=van der Klis
 |series=Cambridge Astrophysics Series
 |year=2006
 |pages=623–665
 |doi=10.1017/CBO9780511536281.017
|arxiv=astro-ph/0303456 |isbn=978-0-521-82659-4|s2cid=18856214 }}</ref>

An estimated 10<sup>41</sup> [[positron]]s escape per second from a typical [[X-ray binary#Low-mass X-ray binary|low-mass X-ray binary]].<ref>{{Cite journal
  | last = Weidenspointner
  | first = Georg
  | title = An asymmetric distribution of positrons in the Galactic disk revealed by gamma-rays
  | journal = Nature
  | date = 2008
  | doi = 10.1038/nature06490
  |bibcode = 2008Natur.451..159W
  | pmid=18185581
  | volume=451
  | issue = 7175
  | pages=159–62| s2cid = 4333175
 }}</ref><ref>[https://www.wired.com/wiredscience/2008/01/mystery-of-anti/ "Mystery of Antimatter Source Solved – Maybe"] by John Borland 2008</ref>