Alpha Gruis is a single, B-type main-sequence star located at a distance of 31 pc.

[14]) It bore the traditional name Alnair or Al Nair (sometimes Al Na'ir in lists of stars used by navigators),[15] from the Arabic al-nayyir "the bright one", itself derived from its Arabic name, al-nayyir min dhanab al-ḥūt (al-janūbiyy), "the bright one from the (southern) fish's tail" (see Aldhanab).

[16] Confusingly, Alnair was also given as the proper name for Zeta Centauri in an astronomical ephemerides in the middle of the 20th century.

[21] Consequently, Alpha Gruis itself is known as 鶴一 (Hè yī, English: First Star of the Crane).

[8] The effective temperature of Alnair's outer envelope is 14,245 K,[7] giving it the blue-white hue characteristic of B-type stars.