Binary star in the constellation Ursa Major
Phi Ursae Majoris
Location of φ Ursae Majoris (circled)
Observation dataEpoch J2000.0 Equinox J2000.0
Constellation
Ursa Major
Right ascension 09h 52m 06.35437s [ 1]
Declination
+54° 03′ 51.5962″[ 1]
Apparent magnitude (V)+4.60[ 2] (5.28 + 5.39) [ 3]
Characteristics
Spectral type
A3 IV + A3 IV [ 4]
U−B color index
+0.08[ 2]
B−V color index
+0.03[ 2]
Astrometry Radial velocity (Rv )± 0.3[ 5] km/s Proper motion (μ) RA: −6.00[ 1] mas /yr Dec.: +19.16[ 1] mas /yr Parallax (π)6.41± 0.59 mas [ 1] Distance 510 ± 50 ly pc ) Absolute magnitude (MV )−1.39[ 6] Orbit [ 7] Period (P)104.6 yr Semi-major axis (a)0.329″ Eccentricity (e)0.436 Inclination (i)19.4° Longitude of the node (Ω)132.5° Periastron epoch (T)1987.52 Argument of periastron (ω)33.3° Details A Mass ± 0.2[ 8] M ☉ Luminosity 347[ 8] L ☉ Surface gravity (log g )± 0.16[ 9] cgs Temperature ± 150[ 9] K Metallicity [Fe/H] ± 0.08[ 9] dex Rotational velocity (v sin i )28[ 8] Other designations φ UMi , 30 Ursae Majoris , BD +54°1331GC 13559HD 85235HIP 48402HR 3894SAO 27408PPM 32355CCDM J09521+5404ABWDS J09521+5404AB[ 10] Database references SIMBAD data
Phi Ursae Majoris , Latinized from φ Ursae Majoris , is a binary star [ 11] 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;[ 2] [ 11] light-years (160 parsecs ) from the Sun based on parallax ,[ 1] radial velocity of −14.7 km/s.[ 5] [ 6]
As of 2017, the components had an angular separation of ″ position angle of 304°.[ 3] period of 105.4 years and eccentricity of 0.44.[ 7] A-type subgiant stars[ 12] stellar classification of A3 IV.[ 4]
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.[ 6]
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-H aud , the Pond.[ 13] Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars , Al-H aud 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 .[ 14]
In Chinese , 文昌 Wén Chāng Administrative Center 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 文昌三 Wén Chāng sān the Third Star of Administrative Center ).[ 15]
References
^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction" . Astronomy and Astrophysics . 474 (2): 653– 664. arXiv :0708.1752 Bibcode :2007A&A...474..653V . doi :10.1051/0004-6361:20078357 . S2CID 18759600 . ^ a b c d Johnson, H. L. (1966), "UBVRIJKL Photometry of the Bright Stars", Communications of the Lunar and Planetary Laboratory , 4 : 99, Bibcode :1966CoLPL...4...99J . ^ a b Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog" , The Astronomical Journal , 122 (6): 3466, Bibcode :2001AJ....122.3466M , doi :10.1086/323920 , retrieved 2015-07-22 ^ a b Edwards, T. W. (April 1976), "MK classification for visual binary components", Astronomical Journal , 81 : 245– 249, Bibcode :1976AJ.....81..245E , doi :10.1086/111879 . ^ a b Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters , 32 (11): 759– 771, arXiv :1606.08053 Bibcode :2006AstL...32..759G , doi :10.1134/S1063773706110065 , S2CID 119231169 . ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters , 38 (5): 331, arXiv :1108.4971 Bibcode :2012AstL...38..331A , doi :10.1134/S1063773712050015 , S2CID 119257644 . ^ a b Hartkopf, W. I.; et al. (June 30, 2006), Sixth Catalog of Orbits of Visual Binary Stars the original on October 30, 2010, retrieved 2017-06-02 . ^ a b c Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics , 537 : A120, arXiv :1201.2052 Bibcode :2012A&A...537A.120Z , doi :10.1051/0004-6361/201117691 , S2CID 55586789 . ^ a b c Prugniel, P.; et al. (2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics , 531 : A165, arXiv :1104.4952 Bibcode :2011A&A...531A.165P , doi :10.1051/0004-6361/201116769 , S2CID 54940439 . ^ "phi UMa" . SIMBAD Centre de données astronomiques de Strasbourg . Retrieved 18 February 2017 .^ a b Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869– 879, arXiv :0806.2878 Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ Kaler, James B. (April 23, 2010), "PHI UMA (Phi Ursae Majoris)" , STARS , retrieved 2019-10-12 . ^ Allen, Richard Hinckley (1899), Star-Names and Their Meanings , New York: G. E. Stechert, p. 442^ Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars (PDF) , Jet Propulsion Laboratory, California Institute of Technology. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 16 日 Archived 2012-02-04 at the Wayback Machine
