Upsilon2 Eridani
Upsilon2 Eridani, officially named Theemin, is a star in the constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.8. Based upon parallax measurements obtained during the Gaia mission, it is approximately 211 light-years distant.
It is an evolved red clump giant star with a stellar classification of G8+ III. The star has 3.15 times the Sun's mass and 14.09 times the Sun's radius. It radiates 114 times the solar luminosity from its outer atmosphere at an effective temperature of 5,023 K.
Nomenclature
υ2 Eridani is the star's Bayer designation.It bore the traditional name Theemin. In 2016, the International Astronomical Union organized a IAU Working Group on [Star Names|Working Group on Star Names] 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.
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, meaning "twins," producing Theemin.
In Chinese, 天園, 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. Consequently, the Chinese name for Upsilon2 Eridani itself is 天園十二.