Editing Sun (section)

=== Formation ===
{{further|Formation and evolution of the Solar System}}
The Sun formed about 4.6&nbsp;billion years ago from the collapse of part of a giant [[molecular cloud]] that consisted mostly of hydrogen and helium and that probably gave birth to many other stars.<!-- We would say 4.57, but there may be uncertainty; for example, https://arxiv.org/pdf/1507.05847.pdf seems to suggest 4.587 rather than 4.567 --><ref name=Zirker2002-7>{{Cite book |last=Zirker |first=Jack B. |title=Journey from the Center of the Sun |date=2002 |publisher=[[Princeton University Press]] |isbn=978-0-691-05781-1 |pages=7–8}}</ref> This age is estimated using [[computer simulation|computer models]] of [[stellar evolution]] and through [[nucleocosmochronology]].<ref name="Bonanno" /> The result is consistent with the [[radiometric dating|radiometric date]] of the oldest Solar System material, at 4.567&nbsp;billion years ago.<ref>{{Cite journal |last1=Amelin |first1=Y. |last2=Krot |first2=A. |last3=Hutcheon |first3=I. |last4=Ulyanov |first4=A. |title=Lead isotopic ages of chondrules and calcium-aluminum-rich inclusions |journal=[[Science (journal)|Science]] |volume=297 |issue=5587 |pages=1678–1683 |date=2002 |doi=10.1126/science.1073950 |pmid=12215641 |bibcode=2002Sci...297.1678A |s2cid=24923770}}</ref><ref name="nature436">{{Cite journal |last1=Baker |first1=J. |last2=Bizzarro |first2=M. |last3=Wittig |first3=N. |last4=Connelly |first4=J. |last5=Haack |first5=H. |title=Early planetesimal melting from an age of 4.5662 Gyr for differentiated meteorites |journal=[[Nature (journal)|Nature]] |volume=436 |issue=7054 |pages=1127–1131 |date=2005 |pmid=16121173 |doi=10.1038/nature03882 |bibcode=2005Natur.436.1127B |s2cid=4304613}}</ref> Studies of ancient [[meteorite]]s reveal traces of stable daughter nuclei of short-lived isotopes, such as [[iron-60]], that form only in exploding, short-lived stars. This indicates that one or more [[supernova]]e must have occurred near the location where the Sun formed. A [[shock wave]] from a nearby supernova would have triggered the formation of the Sun by compressing the matter within the molecular cloud and causing certain regions to collapse under their own gravity.<ref>{{Cite journal |last1=Williams |first1=J. |title=The astrophysical environment of the solar birthplace |journal=Contemporary Physics |volume=51 |issue=5 |pages=381–396 |year=2010 |doi=10.1080/00107511003764725 |bibcode=2010ConPh..51..381W |arxiv=1008.2973 |citeseerx=10.1.1.740.2876 |s2cid=118354201}}</ref> As one fragment of the cloud collapsed it also began to rotate due to [[conservation of angular momentum]] and heat up with the increasing pressure.<ref>{{Cite web |last=Glozman |first=Igor |date=2022 |title=Formation of the Solar System |url=https://people.highline.edu/iglozman/classes/astronotes/solsys_form.htm |access-date=16 January 2022 |website=[[Highline College]] |publication-place=Des Moines, WA |archive-date=26 March 2023 |archive-url=https://web.archive.org/web/20230326035535/https://people.highline.edu/iglozman/classes/astronotes/solsys_form.htm |url-status=live}}</ref> Much of the mass became concentrated in the centre, whereas the rest flattened out into a disk that would become the planets and other Solar System bodies.<ref>{{cite journal |last1=D'Angelo |first1=G. |last2=Lubow |first2=S. H. |title=Three-dimensional Disk-Planet Torques in a Locally Isothermal Disk |journal=The Astrophysical Journal |date=2010 |volume=724 |issue=1 |pages=730–747 |doi=10.1088/0004-637X/724/1/730 |arxiv=1009.4148 |bibcode=2010ApJ...724..730D |s2cid=119204765}}</ref><ref>{{cite book |last1=Lubow |first1=S. H. |last2=Ida |first2=S. |chapter=Planet Migration |bibcode=2010exop.book..347L |title=Exoplanets |publisher=University of Arizona Press |location=Tucson |editor-first=S. |editor-last=Seager |pages=347–371 |year=2011 |arxiv=1004.4137}}</ref> Gravity and pressure within the core of the cloud generated a lot of heat as it accumulated more matter from the surrounding disk, eventually triggering [[stellar nucleosynthesis|nuclear fusion]].<ref>{{Cite web |last=Jones |first=Andrew Zimmerman |date=30 May 2019 |title=How Stars Make All of the Elements |url=https://www.thoughtco.com/stellar-nucleosynthesis-2699311 |access-date=16 January 2023 |website=[[ThoughtCo]] |archive-date=11 July 2023 |archive-url=https://web.archive.org/web/20230711191648/https://www.thoughtco.com/stellar-nucleosynthesis-2699311 |url-status=live}}</ref>

The stars [[HD 162826]] and [[HD 186302]] share similarities with the Sun and are hypothesised to be its stellar siblings, formed in the same molecular cloud.<ref>{{cite web |url=http://www.natureworldnews.com/articles/6974/20140509/astronomers-find-suns-sibling-called-hd-162826.htm |title=Astronomers Find Sun's Sibling 'HD 162826' |date=9 May 2014 |publisher=Nature World News |access-date=16 January 2022 |archive-date=3 March 2016 |archive-url=https://web.archive.org/web/20160303235530/http://www.natureworldnews.com/articles/6974/20140509/astronomers-find-suns-sibling-called-hd-162826.htm |url-status=live}}</ref><ref>{{cite web |url=https://www.universetoday.com/140598/astronomers-find-one-of-the-suns-sibling-stars-born-from-the-same-solar-nebula-billion-of-years-ago/ |title=Astronomers Find One of the Sun's Sibling Stars. Born From the Same Solar Nebula Billions of Years Ago |first=Matt |last=Williams |date=21 November 2018 |website=[[Universe Today]] |access-date=7 October 2022 |archive-date=26 March 2023 |archive-url=https://web.archive.org/web/20230326035623/https://www.universetoday.com/140598/astronomers-find-one-of-the-suns-sibling-stars-born-from-the-same-solar-nebula-billion-of-years-ago/ |url-status=live}}</ref>