Editing Proxima Centauri (section)

== Life phases ==
[[File:Alpha, Beta and Proxima Centauri (1).jpg|left|thumb|upright=1.4|[[Alpha Centauri]] A and B are the bright apparent star to the left, which are in a triple star system with Proxima Centauri, circled in red. The bright star system to the right is the unrelated [[Beta Centauri]].]]
A red dwarf with the mass of Proxima Centauri will remain on the main sequence for about four trillion years. As the proportion of helium increases because of hydrogen fusion, the star will become smaller and hotter, gradually transforming into a so-called [[Blue dwarf (red-dwarf stage)|"blue dwarf"]]. Near the end of this period it will become significantly more luminous, reaching 2.5% of the Sun's luminosity ({{Solar luminosity|link=y}}) and warming any orbiting bodies for a period of several billion years. When the hydrogen fuel is exhausted, Proxima Centauri will then evolve into a helium [[white dwarf]] (without passing through the [[red giant]] phase) and steadily lose any remaining heat energy.<ref name="adams" /><ref>{{cite journal |last1=Adams |first1=Fred C. |last2=Laughlin |first2=Gregory |name-list-style=amp |year=1997 |title=A Dying Universe: The Long Term Fate and Evolution of Astrophysical Objects |journal=Reviews of Modern Physics |volume=69 |issue=2 |pages=337–372 |arxiv=astro-ph/9701131 |bibcode=1997RvMP...69..337A |doi=10.1103/RevModPhys.69.337 |s2cid=12173790}}</ref>

The [[Alpha Centauri]] system may have formed through a low-mass star being dynamically captured by a more massive binary of {{Solar mass|1.5–2}} within their embedded star cluster before the cluster dispersed.<ref>{{cite journal |last=Kroupa |first=Pavel |date=1995 |title=The dynamical properties of stellar systems in the Galactic disc |journal=MNRAS |volume=277 |issue=4 |pages=1507–1521 |arxiv=astro-ph/9508084 |bibcode=1995MNRAS.277.1507K |doi=10.1093/mnras/277.4.1507 |doi-access=free |s2cid=15557806}}</ref> However, more accurate measurements of the radial velocity are needed to confirm this hypothesis.<ref name="apj132">{{cite journal |last1=Wertheimer |first1=Jeremy G. |last2=Laughlin |first2=Gregory |date=2006 |title=Are Proxima and α Centauri gravitationally bound? |journal=[[The Astronomical Journal]] |volume=132 |issue=5 |pages=1995–1997 |arxiv=astro-ph/0607401 |bibcode=2006AJ....132.1995W |doi=10.1086/507771 |s2cid=16650143}}</ref> If Proxima Centauri was bound to the Alpha Centauri system during its formation, the stars are likely to share the same [[chemical element|elemental]] composition. The gravitational influence of Proxima might have disturbed the Alpha Centauri [[protoplanetary disk]]s. This would have increased the delivery of [[Volatile (astrogeology)|volatiles]] such as water to the dry inner regions, so possibly enriching any [[terrestrial planet]]s in the system with this material.<ref name="apj132" />

[[File:Orbital plot of Proxima Centauri.jpg|thumb|upright=1.2|Orbital plot of Proxima Centauri around the bright apparent star Alpha Centauri AB, with position change marked (in thousands of years).]]
Alternatively, Proxima Centauri may have been captured at a later date during an encounter, resulting in a highly eccentric orbit that was then stabilized by the [[galactic tide]] and additional stellar encounters. Such a scenario may mean that Proxima Centauri's planetary companions have had a much lower chance for orbital disruption by Alpha Centauri.<ref name="FengJones2018">{{cite journal |last1=Feng |first1=F. |last2=Jones |first2=H. R. A. |date=January 2018 |title=Was Proxima captured by Alpha Centauri A and B? |journal=Monthly Notices of the Royal Astronomical Society |volume=473 |issue=3 |pages=3185−3189 |arxiv=1709.03560 |bibcode=2018MNRAS.473.3185F |doi=10.1093/mnras/stx2576 |doi-access=free |s2cid=55711316}}</ref> As the members of the Alpha Centauri pair continue to evolve and lose mass, Proxima Centauri is predicted to become unbound from the system in around 3.5&nbsp;billion years from the present. Thereafter, the star will steadily diverge from the pair.<ref>{{cite journal |last=Beech |first=M. |date=2011 |title=The Far Distant Future of Alpha Centauri |journal=Journal of the British Interplanetary Society |volume=64 |pages=387–395 |bibcode=2011JBIS...64..387B}}</ref>