Ophiucus 5

Rasalhague
Alpha Ophiuchi

Distance (Light Years)
46.7 ± 0.6
Visual Magnitude
2.08
Color (B-V)
0.15
Names For This Star
Rasalhague, alternatively Ras Alhague, derives from the Arabic name for this star, Al Ras al Hawwa, "The Head of the Serpent-Charmer."

Description of the Star
Rasalhague is a hot, white A5III giant having 26 times the luminosity of the sun, and 2.4 times the diameter.
Rasalhague has an unseen companion revolving in an orbit at an angular separation of 0.065 arc sec from the primary, that is, just under 1 AU from the central star. The period of the orbit is 8.5 year. According to Burnham the masses would be 2.4 solar masses and 0.6 solar masses for the giant and the companion respectively.