Editing Star (section)

===Diameter===
{{Main|List of largest stars|List of smallest stars|Solar radius}}
Due to their great distance from the Earth, all stars except the Sun appear to the unaided eye as shining points in the night sky that [[Twinkling|twinkle]] because of the effect of the Earth's atmosphere. The Sun is close enough to the Earth to appear as a disk instead, and to provide daylight. Other than the Sun, the star with the largest apparent size is [[R Doradus]], with an [[angular diameter]] of only 0.057 [[arcsecond]]s.<ref>{{cite news
 | title=The Biggest Star in the Sky | publisher=ESO
 | date=1997-03-11 | url=http://www.eso.org/public/news/eso9706/
 | access-date=2006-07-10}}</ref>

The disks of most stars are much too small in [[Angular diameter|angular size]] to be observed with current ground-based optical telescopes, so [[Interferometry|interferometer]] telescopes are required to produce images of these objects. Another technique for measuring the angular size of stars is through [[occultation]]. By precisely measuring the drop in brightness of a star as it is occulted by the [[Moon]] (or the rise in brightness when it reappears), the star's angular diameter can be computed.<ref>{{cite journal
 | last1=Ragland | first1=S. | last2=Chandrasekhar | first2=T.
 | last3=Ashok | first3=N. M.
 | title=Angular Diameter of Carbon Star Tx-Piscium from Lunar Occultation Observations in the Near Infrared
 | journal=Journal of Astrophysics and Astronomy
 | date=1995 | volume=16 | page=332
 | bibcode=1995JApAS..16..332R}}</ref>

Stars range in size from neutron stars, which vary anywhere from 20 to {{convert|40|km|0|abbr=on}} in diameter, to [[supergiant]]s like [[Betelgeuse]] in the [[Orion constellation]], which has a diameter about 640 times that of the Sun<ref>{{Cite journal |last1=Mittag |first1=M. |last2=Schröder |first2=K.-P. |last3=Perdelwitz |first3=V. |last4=Jack |first4=D. |last5=Schmitt |first5=J. H. M. M. |date=January 2023 |title=Chromospheric activity and photospheric variation of &alpha; Ori during the great dimming event in 2020 |journal=Astronomy & Astrophysics |volume=669 |pages=A9 |doi=10.1051/0004-6361/202244924 |issn=0004-6361|arxiv=2211.04967 |bibcode=2023A&A...669A...9M }}</ref> with a much lower [[density]].<ref>{{cite web
 | last=Davis | first=Kate | date=2000-12-01
 | url=http://www.aavso.org/vstar/vsots/1200.shtml
 | title=Variable Star of the Month – December, 2000: Alpha Orionis
 | publisher=AAVSO | access-date=2006-08-13 | archive-url=https://web.archive.org/web/20060712000904/http://www.aavso.org/vstar/vsots/1200.shtml <!-- Bot retrieved archive --> | archive-date=2006-07-12}}</ref>