Phi Ursae Majoris

Phi Ursae Majoris

Location of φ Ursae Majoris (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Ursa Major
Right ascension	09^h 52^m 06.36^s
Declination	+54° 03' 51.4"
Apparent magnitude (V)	+4.55
Characteristics
Spectral type	A3IV
Astrometry
Distance	436 ly (134 pc)
Other designations
φ Ursae Majoris, φ UMa, Phi UMa, 30 Ursae Majoris, BD+54 1331, CCDM J09521+5404AB, GC 13559, HD 85235, HIP 48402, HR 3894, IDS 09453+5432, PPM 32355, SAO 27408, WDS J09521+5404AB
Database references
SIMBAD	data

Phi Ursae Majoris (Phi UMa, φ Ursae Majoris, φ UMa) is binary star in constellation of Ursa Major, which is separated in 0.245 arcseconds.^[1] Both of components are white A-type subgiant.^[2] It is approximately 436 light years from Earth.

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.^[3]

Phi Ursae Majoris will come closest to the Sun 4.7 million years from now when it will brighten to magnitude 3.88 from a distance of 370 light years.^[3]

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,^[4]
• In Chinese, 文昌 (Wén Chāng), 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, φ Ursae Majoris itself is known as 文昌三 (Wén Chāng sān, English: the Third Star of Administrative Center.).^[5]

References

1. Barnaby, David; Spillar, Earl; Christou, Julian.C; Drummond, Jack.D (January 2000), "Measurements of Binary Stars with the Starfire Optical Range Adaptive Optics Systems", The Astronomical Journal 119 (1): 378–389, Bibcode:2000AJ....119..378B, doi:10.1086/301155
2. PHI UMA (Phi Ursae Majoris)
3. Phi Ursae Majoris (HIP 48402)
4. Allen, Richard Hinckley (1899), Star-Names and Their Meanings, New York: G. E. Stechert, p. 442
5. (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 16 日