What is Pollux (star)?
'''Pollux''' is a red [[giant star]]. It is the brightest star in the [[Gemini]] [[constellation]]. It's [[diameter]] is {{convert|12255584|km|abbr=off}}.<ref>{{cite journal|url=https://www.aanda.org/articles/aa/abs/2006/37/aa5445-06/aa5445-06.html|title=Confirmation of the planet hypothesis for the long-period radial velocity variations of β Geminorum|first1=M. P.|last1=Döllinger|first2=D. B.|last2=Paulson|first3=M.|last3=Esposito|first4=M.|last4=Hartmann|first5=S.|last5=Yang|first6=G. a. H.|last6=Walker|first7=S. H.|last7=Saar|first8=E. W.|last8=Guenther|first9=M.|last9=Endl|first10=W. D.|last10=Cochran|first11=A. P.|last11=Hatzes|date=1 October 2006|journal=Astronomy & Astrophysics|volume=457|issue=1|pages=335–341|via=www.aanda.org|doi=10.1051/0004-6361:20065445|arxiv=astro-ph/0606517|bibcode=2006A&A...457..335H|s2cid=14319327}}</ref> Once a type A star, Pollux has used all the [[hydrogen]] in its core and expanded to become a K-type giant star.<ref>{{cite journal|url=https://www.aanda.org/articles/aa/abs/2009/34/aa12050-09/aa12050-09.html|title=Discovery of a weak magnetic field in the photosphere of the single giant Pollux|first1=J.|last1=Power|first2=C. P.|last2=Folsom|first3=S. Van|last3=Eck|first4=R.|last4=Cabanac|first5=E.|last5=Alecian|first6=J.-F.|last6=Donati|first7=P.|last7=Petit|first8=T.|last8=Roudier|first9=W. W.|last9=Weiss|first10=C.|last10=Catala|first11=C.|last11=Charbonnel|first12=R.|last12=Konstantinova-Antova|first13=G. A.|last13=Wade|first14=M.|last14=Aurière|date=1 September 2009|journal=Astronomy & Astrophysics|volume=504|issue=1|pages=231–237|via=www.aanda.org|doi=10.1051/0004-6361/200912050|arxiv=0907.1423|bibcode=2009A&A...504..231A|s2cid=14295272}}</ref> It is located at a distance of 34 [[Light year|light years]], which makes it the closest giant star to the [[Sun]]. In 2006, an [[extrasolar planet]] (designated [[Pollux b]], formally named Thestias) was confirmed to be orbiting the star at a distance of 1.64 [[Astronomical unit|AU]] in nearly a [[circular orbit]].<ref>{{Cite journ