Due to its unusually rapid rotation, Epsilon Sagittarii is more likely a product of stellar binary interaction.

[5] The system displays an excess emission of infrared radiation, which would suggest the presence of a circumstellar disk of dust,[12] but these claims were later found to be doubtful.

[6] As of 2001, the secondary star, ε Sagittarii B, is located at an angular separation of 2.392 arcseconds from the primary along a position angle of 142.3°.

[6] Prior to its 1993 identification using an adaptive optics coronagraph, this companion may have been responsible for the spectral anomalies that were attributed to the primary star.

It bore the traditional name Kaus Australis, which derived from the Arabic قوس qaws 'bow' and Latin austrālis 'southern'.

Consequently, the Chinese name for Epsilon Sagittarii itself is 箕宿三 (Jī Sù sān, English: the Third Star of Winnowing Basket.