What is VX Sagittarii?
[[File:VX Sagittarii Red Supergiant Star.png|250px|thumb|VX Sagittarii, one of [[Red supergiant star]].]] '''VX Sagittarii''', also known as '''HIP 88838''', is a [[red hypergiant star]] with a diameter [[Pulsating variable|pulsating]] between 1.120<ref>{{Cite journal|last1=Xu|first1=Shuangjing|last2=Zhang|first2=Bo|last3=Reid|first3=Mark J.|last4=Menten|first4=Karl M.|last5=Zheng|first5=Xingwu|last6=Wang|first6=Guangli|date=May 2018|title=The Parallax of the Red Hypergiant VX Sgr with Accurate Tropospheric Delay Calibration|journal=The Astrophysical Journal|language=en|volume=859|issue=1|pages=14|doi=10.3847/1538-4357/aabba6|arxiv=1804.00894|bibcode=2018ApJ...859...14X|s2cid=55572194|issn=0004-637X|doi-access=free }}</ref> and 1.940 times [[Sun]],<ref>{{Cite journal|last1=Lockwood|first1=G. W.|last2=Wing|first2=Robert F.|date=1982-02-01|title=The light and spectrum variations of VX Sagittarii, an extremely cool supergiant|url=https://academic.oup.com/mnras/article/198/2/385/995840|journal=Monthly Notices of the Royal Astronomical Society|language=en|volume=198|issue=2|pages=385–404|doi=10.1093/mnras/198.2.385|issn=0035-8711}}</ref> a [[temperature]] between 3.200 and 3.400 degrees [[Kelvin]].<ref>{{Cite journal|last1=Chiavassa|first1=A.|last2=Lacour|first2=S.|last3=Millour|first3=F.|last4=Driebe|first4=T.|last5=Wittkowski|first5=M.|last6=Plez|first6=B.|last7=Thiébaut|first7=E.|last8=Josselin|first8=E.|last9=Freytag|first9=B.|date=2010-02-01|title=VLTI/AMBER spectro-interferometric imaging of VX Sagittarii's inhomogenous outer atmosphere|url=https://www.aanda.org/articles/aa/abs/2010/03/aa13288-09/aa13288-09.html|journal=Astronomy & Astrophysics|language=en|volume=511|pages=A51|doi=10.1051/0004-6361/200913288|arxiv=0911.4422|bibcode=2010A&A...511A..51C|s2cid=55877127|issn=0004-6361}}</ref> The star has a pulsation period of 732 days and is located 1.5 kiloparsecs away from the [[Earth]]. Older studies show significantly higher temperatures.<ref>{{Cite journal|last1=de Jager|first1=C.|last2=Nieuwenhuijzen|first2=H