Editing Star (section)

===Age===
{{main|Stellar age estimation}}

Most stars are between 1&nbsp;billion and 10&nbsp;billion years old. Some stars may even be close to 13.8&nbsp;billion years old—the observed [[age of the universe]]. The oldest star yet discovered, [[HD 140283]], nicknamed Methuselah star, is an estimated 14.46 ± 0.8&nbsp;billion years old.<ref name=Bond-140283 /> (Due to the uncertainty in the value, this age for the star does not conflict with the age of the universe, determined by the [[Planck (spacecraft)|Planck satellite]] as 13.799 ± 0.021).<ref name=Bond-140283 /><ref name="Planck 2015">{{cite journal
 |author=Planck Collaboration
 |year=2016
 |title=Planck 2015 results. XIII. Cosmological parameters (See Table 4 on page 31 of pfd).
 |arxiv=1502.01589
|bibcode = 2016A&A...594A..13P
 |doi=10.1051/0004-6361/201525830
 |volume=594
 |journal=Astronomy & Astrophysics
 |pages=A13|s2cid=119262962
 }}</ref>

The more massive the star, the shorter its lifespan, primarily because massive stars have greater pressure on their cores, causing them to burn hydrogen more rapidly. The most massive stars last an average of a few million years, while stars of minimum mass (red dwarfs) burn their fuel very slowly and can last tens to hundreds of billions of years.<ref>{{cite magazine
 | last1=Naftilan | first1=S. A. | last2=Stetson | first2=P. B.
 | date=2006-07-13
 | url=https://www.scientificamerican.com/article/how-do-scientists-determi/
 | title=How do scientists determine the ages of stars? Is the technique really accurate enough to use it to verify the age of the universe?
 | magazine=Scientific American
 | access-date=2007-05-11}}</ref><ref>{{cite journal |last1=Laughlin |first1=G. |last2=Bodenheimer |first2=P. |last3=Adams |first3=F. C. |date=1997 |title=The End of the Main Sequence |journal=The Astrophysical Journal |volume=482 |issue=1 |pages=420–432 |bibcode=1997ApJ...482..420L |doi=10.1086/304125 |doi-access=free}}</ref>

{| class="wikitable" style="text-align: center;"
|+ Lifetimes of stages of stellar evolution in billions of years<ref name=pols>{{cite journal|bibcode=1998MNRAS.298..525P|title=Stellar evolution models for Z = 0.0001 to 0.03|journal=Monthly Notices of the Royal Astronomical Society|volume=298|issue=2|pages=525|last1=Pols|first1=Onno R.|last2=Schröder|first2=Klaus-Peter|last3=Hurley|first3=Jarrod R.|last4=Tout|first4=Christopher A.|last5=Eggleton|first5=Peter P.|year=1998|doi=10.1046/j.1365-8711.1998.01658.x|doi-access=free}}</ref>
|-
! Initial Mass ({{solar mass|link=yes}})
!width="20%"| Main Sequence
!width="20%"| Subgiant
!width="20%"| First Red Giant
!width="20%"| Core He Burning
|-
| 1.0 || 9.33 || 2.57 || 0.76 || 0.13
|-
| 1.6 || 2.28 || 0.03 || 0.12 || 0.13
|-
| 2.0 || 1.20 || 0.01 || 0.02 || 0.28
|-
| 5.0 || 0.10 || 0.0004 || 0.0003 || 0.02
|}