Phi Ursae Majoris

Phi Ursae Majoris, Latinized from φ Ursae Majoris, is binary star system in the northern constellation of Ursa Major. It is white-hued and is visible to the naked eye with a combined apparent visual magnitude of +4.60; the primary is magnitude 5.28 while the secondary is magnitude 5.39. The system is located at a distance of approximately 510 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −14.7 km/s. It should make its closest approach at a distance of around in about 4.7 million years.
As of 2017, the components had an angular separation of along a position angle of 304°. They are orbiting each other with a period of 105.4 years and eccentricity of 0.44. Both of components are A-type subgiant stars with a stellar classification of A3 IV.
Phi Ursae Majoris is moving through the Galaxy at a speed of 21.6 km/s relative to the Sun. Its projected Galactic orbit carries it between 24,000 and 46,000 light years from the center of the Galaxy.
Naming.
With τ, h, υ, θ, e, and f, it composed the Arabic asterism "Sarīr Banāt al-Na'sh", the Throne of the daughters of "Na'sh", and "Al-Haud", the Pond. According to the catalogue of stars in the "Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars", "Al-Haud" were the title for seven stars : f as "Alhaud I", τ as "Alhaud II", e as "Alhaud III", h as "Alhaud IV", θ as "Alhaud V", υ as "Alhaud VI" and this star (φ) as "Alhaud VII".
In Chinese, (), meaning "Administrative Center", refers to an asterism consisting of φ Ursae Majoris, υ Ursae Majoris, θ Ursae Majoris, 15 Ursae Majoris and 18 Ursae Majoris. Consequently, the Chinese name for φ Ursae Majoris itself is known as (, ).