The WGSN's first bulletin of July 2016[15] included a table of the first two collections of approved names, formally listing Alpha Ophiuchi as Rasalhague.

[10] The mass of the secondary suggests that it has a stellar classification in the range K5V to K7V, which indicates it is a main sequence star that is still generating energy by the thermonuclear fusion of hydrogen at its core.

The stellar classification of A5IVnn indicates that the primary is a bluish-white subgiant star that has evolved away from the main sequence after consuming the hydrogen at its core.

[3] It is radiating about 25 times the luminosity of the Sun and has an effective temperature of about 8,000 K, giving it the characteristic white hue of an A-type star.

[17][18] The spectrum of Alpha Ophiuchi shows an anomalously high level of absorption of the lines for singly-ionized calcium (Ca II).