Alpha Leporis (α Leporis, abbreviated Alpha Lep, α Lep), formally named Arneb,[1] [2] is the brightest star in the constellation of Lepus.
Alpha Leporis is the star's Bayer designation. The traditional name Arneb comes from the Arabic أرنب ’arnab 'hare' ('Lepus' is Latin for hare). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[3] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[4] included a table of the first two batches of names approved by the WGSN; which included Arneb for this star.
In Chinese, Chinese: 廁 (Chinese: Cè), meaning Toilet, refers to an asterism consisting of α Leporis, β Leporis, γ Leporis and δ Leporis.[5] Consequently, the Chinese name for α Leporis itself is Chinese: 廁一 (Chinese: Cè yī), "the First Star of Toilet".[6]
This is a massive star with about 12 times the mass of the Sun. The interferometer-measured angular diameter of this star, after correction for limb darkening, is . At an estimated distance of 2218abbr=offNaNabbr=off, this yields a physical size of about 129 times the radius of the Sun. An earlier calculation based on a luminosity of and its effective temperature give Arneb a radius of, while a 2017 catalog gives . Alpha Leporis has a stellar classification of F0 Ib, with the Ib luminosity class indicating that it is a lower luminosity yellow supergiant star. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. The effective temperature of the outer envelope is about 6,850–7,500K, which gives the star a yellow-white hue that is typical of F-type stars. It is an estimated 17.5 million years old.
Arneb is an older, dying star that has already passed through a red supergiant phase and is now contracting and heating up in the latter phases of stellar evolution, in a blue loop. Based upon its estimated mass, it is expected to end its life in a spectacular stellar explosion known as a supernova. However, this is not expected to happen for another million years.
USS Arneb (AKA-56) was a ship of the United States Navy.