Upsilon2 Eridani
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Upsilon2 Eridani (υ² Eridani, abbreviated Upsilon2 Eri, υ2 Eri), officially named Theemin Template:IPAc-en,[1][2] is a star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.8.[3] Based upon parallax measurements obtained during the Hipparcos mission,[4] it is approximately 66 parsecs (214 light-years) from the Sun.
It is an evolved red clump[5] giant star with a stellar classification of G8+ III.[6] The measured angular diameter is 2.21 mas.[7] At the star's distance, this yields a physical size of around 16 times the radius of the Sun.[8] It radiates 138[9] times the solar luminosity from its outer atmosphere at an effective temperature of 5074 K.[10]
Nomenclature
υ2 Eridani (Latinised to Upsilon2 Eridani) is the star's Bayer designation.
It bore the traditional name Theemin (also written as Theemim and Beemin).[11] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[12] to catalogue and standardize proper names for stars. The WGSN approved the name Theemin for this star on February 1, 2017, and it is now included in the List of IAU-approved Star Names.[2]
In the Almagest, Ptolemy called it hē kampē, "the bend in the river;" Arab writers corrupted this to bhmn, later becoming beemin, beemun in the West. Subsequently, its etymology was incorrectly derived from Hebrew תאומים (te'omim), meaning "twins," producing Theemin.[13][14]
In Chinese, Template:Lang (Template:Lang), meaning Celestial Orchard, refers to an asterism consisting of Upsilon2 Eridani, Chi Eridani, Phi Eridani, Kappa Eridani, HD 16754, HD 23319, Theta Eridani, HD 24072, HD 24160, Upsilon4 Eridani, Upsilon3 Eridani and Upsilon1 Eridani.[15] Consequently, the Chinese name for Upsilon2 Eridani itself is Template:Lang (Template:Lang, Template:Langx).[16]
References
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- ↑ Template:Cite web
- ↑ Template:Cite book
- ↑ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
- ↑ Template:In lang 香港太空館 - 研究資源 - 亮星中英對照表 Template:Webarchive, Hong Kong Space Museum. Accessed on line November 23, 2010.