Delta Sagittarii


Delta Sagittarii, formally named Kaus Media, is a star in the southern zodiac constellation of Sagittarius. The apparent visual magnitude of this star is +2.70, making it easily visible to the naked eye. Parallax measurements place the distance at roughly from the Sun.

Properties

Eggleton and Tokovinin list Delta Sagittarii as a binary star system consisting of an evolved K-type giant star with a stellar classification of K3 III, and a white dwarf companion. The giant has an estimated mass three times that of the Sun, and is most likely fusing helium to carbon in its core. It has an estimated 3.21 times the mass of the Sun and is about 260million years old.
Delta Sagittarii has three dim visual companions:
  • a 14th magnitude star at a separation of 26 arcseconds,
  • a 15th magnitude star at a separation of 40 arcseconds, and
  • a 13th magnitude star at a separation of 58 arcseconds from the primary.

    Nomenclature

δ Sagittarii is the star's Bayer designation.
It bore the traditional names Kaus Media, Kaus Meridionalis, and Media, which derive from the qaws and . In 2016, the International Astronomical Union organized a Working Group on Star Names to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Kaus Media for this star.
In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, this star was designated Thani al Waridah, meaning 'second of Warida'.
In Chinese astronomy, 箕 Jī refers to an asterism consisting of Delta Sagittarii, Gamma2 Sagittarii, Epsilon Sagittarii and Eta Sagittarii. Consequently, the Chinese name for Delta Sagittarii itself is 箕宿二 Jī Sù èr.
This star, together with Gamma Sagittarii, Epsilon Sagittarii, Zeta Sagittarii, Lambda Sagittarii, Sigma Sagittarii, Tau Sagittarii and Phi Sagittarii, comprises the Teapot asterism.
In Hindu astrology, this star is also called Purvashada Nakshatra.