Delta Arietis (δ Arietis, abbreviated Delta Ari, δ Ari), officially named Botein , is a star in the northern constellation of Aries, 1.8 degrees north of the ecliptic.
The apparent visual magnitude is 4.35, so it is visible to the naked eye.
It has an annual parallax shift of 19.22 mas; corresponding to a distance of about  from the Sun.
Nomenclature
δ Arietis (Latinised to Delta Arietis) is the star's Bayer designation.
It bore the traditional name Botein which is derived from Al Bīrūnī's Al Buṭayn (Arabic: البُطَين), the diminutive of Al Baṭn, "the Belly".
This is the name of a star association consisting of this star, Epsilon Arietis, Zeta Arietis, Pi Arietis, and Rho3 Arietis According to a 1971 NASA catalogue of stars, Al Buṭain was the title for five stars: Delta Arietis (listed as Botein), Pi Arietis (as Al Buṭain I), Rho3 Arietis (Al Buṭain II), Epsilon Arietis (Al Buṭain III) and Zeta Arietis (Al Buṭain IV).Jack W. Rhoads - Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology; November 15, 1971 In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars.
The WGSN approved the name Botein for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Nir al Botain, which was translated into Latin as Lucida Ventris, meaning "the brightest of the belly".
In Chinese,  (), meaning Yin Force, refers to an asterism consisting of Delta Arietis, 63 Arietis, Zeta Arietis, Tau Arietis and 65 Arietis. 中國星座神話
, written by 陳久金.
Published by 台灣書房出版有限公司, 2005, .
Consequently, the Chinese name for Delta Arietis itself is  (, .) 香港太空館 - 研究資源 - 亮星中英對照表 , Hong Kong Space Museum.
Accessed on line November 23, 2010.
Properties
Delta Arietis is an evolved giant star with a stellar classification of K2 III.
It belongs to a population known as red clump giants, which means it is generating energy through the fusion of helium at its core.
With close to twice the mass of the Sun, the outer envelope has expanded until it is around ten times the Sun's radius.
It shines with 45 times the Sun's luminosity at an effective temperature of 4,810 K, giving it the orange-hued glow of a K-type star.
It is a suspected variable star that ranges in magnitude from 4.33 to 4.37.
References
External links
HR 951
The Constellations and Named Stars
Image Delta Arietis
