Pollux is a red giant star. It is the brightest star in the Gemini constellation. It's diameter is 12,255,584 kilometres (7,615,267 miles).[1] Once a type A star, Pollux has used all the hydrogen in its core and expanded to become a K-type giant star.[2]
It is located at a distance of 34 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 AU in nearly a circular orbit.[3]
Döllinger, M. P.; Paulson, D. B.; Esposito, M.; Hartmann, M.; Yang, S.; Walker, G. a. H.; Saar, S. H.; Guenther, E. W.; Endl, M.; Cochran, W. D.; Hatzes, A. P. (1 October 2006). "Confirmation of the planet hypothesis for the long-period radial velocity variations of β Geminorum". Astronomy & Astrophysics. 457 (1): 335–341. arXiv:astro-ph/0606517. Bibcode:2006A&A...457..335H. doi:10.1051/0004-6361:20065445. S2CID 14319327 – via www.aanda.org. Power, J.; Folsom, C. P.; Eck, S. Van; Cabanac, R.; Alecian, E.; Donati, J.-F.; Petit, P.; Roudier, T.; Weiss, W. W.; Catala, C.; Charbonnel, C.; Konstantinova-Antova, R.; Wade, G. A.; Aurière, M. (1 September 2009). "Discovery of a weak magnetic field in the photosphere of the single giant Pollux". Astronomy & Astrophysics. 504 (1): 231–237. arXiv:0907.1423. Bibcode:2009A&A...504..231A. doi:10.1051/0004-6361/200912050. S2CID 14295272 – via www.aanda.org. Hatzes, A. P.; Cochran, W. D.; Guenther, M. Endl E. W.; Saar, S. H.; Walker, G. A. H.; Yang, S.; Hartmann, M.; Esposito, M.; Paulson, D. B. (2006). "Confirmation of the Planet Hypothesis for the Long-period Radial Velocity Variations of Beta Geminorum". Astronomy & Astrophysics. 457 (1): 335–341. arXiv:astro-ph/0606517. doi:10.1051/0004-6361:20065445. ISSN 0004-6361. S2CID 14319327.
