10 Ursae Majoris

10 Ursae Majoris
Observation data
Epoch J2000      Equinox J2000
Constellation Lynx
Right ascension  09h 00m 38.38067s[1]
Declination +41° 46′ 58.6051″[1]
Apparent magnitude (V) 3.960[2] (4.18 / 6.48)[3]
Spectral type F3V + K0V[4]
U−B color index +0.04[2]
B−V color index +0.43[2]
Radial velocity (Rv)26.4 ± 0.9[5] km/s
Proper motion (μ) RA: -474.31[1] mas/yr
Dec.: -204.21[1] mas/yr
Parallax (π)62.23 ± 0.68[1] mas
Distance52.4 ± 0.6 ly
(16.1 ± 0.2 pc)
Period (P)7691.0 ± 1.8 d
Semi-major axis (a)0.64566 ± 0.00056″
Eccentricity (e)0.15075 ± 0.00084
Inclination (i)131.366 ± 0.099°
Longitude of the node (Ω)203.74 ± 0.10°
Periastron epoch (T)JD 2449263.1 ± 9.1
Argument of periastron (ω)
32.30 ± 0.44°
10 UMa A
Mass1.44 M
Luminosity4.285 L
Temperature6740 K
10 UMa B
Mass0.89 M
Luminosity0.638 L
Temperature5250 K
Other designations
10 UMa, BD+42° 1956, FK5 339, GJ 332, HD 76943, HIP 44248, HR 3579, SAO 42642[7]
Database references
10 UMa B

10 Ursae Majoris is a binary star system in the northern constellation of Lynx. It is visible to the naked eye as a faint star with a combined apparent visual magnitude of 3.960.[2] This system is fairly close to the Sun, at 53 light-years (16.1 pc) away from Earth.[1] It is the third-brightest object in Lynx. Originally in the neighbouring constellation Ursa Major, it became part of Lynx with the official laying down of the constellation borders.[8] The system is moving further from the Earth with a heliocentric radial velocity of 26.4 km/s.[5] It is a probable member of the Hyades supercluster.[9]

This is a spectroscopic binary—orbital motion from the two stars can be detected by Doppler shifts in their spectra. In this case, the two stars can also be split by differential astrometry. The magnitude 4.18[3] primary has a mass of 1.44 M and the fainter secondary, 0.89 M.[4] The primary is an F-type main-sequence star radiating 4.3 times the Sun's luminosity, and the magnitude 6.48[3] secondary is K-type with 0.6 times the luminosity of the Sun. The two orbit each other every 21.057 years with an eccentricity of 0.15.[6]


  1. ^ a b c d e f van Leeuwen, F.; et al. (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.
  2. ^ a b c d Oja, T. (1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89 (2): 415–419. Bibcode:1991A&AS...89..415O.
  3. ^ a b c "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Retrieved 18 June 2017.
  4. ^ a b c Eggl, S.; Pilat-Lohinger, E.; Funk, B.; Georgakarakos, N.; Haghighipour, N. (2012). "Circumstellar habitable zones of binary-star systems in the solar neighbourhood". Monthly Notices of the Royal Astronomical Society. 428 (4): 3104. arXiv:1210.5411. Bibcode:2013MNRAS.428.3104E. doi:10.1093/mnras/sts257.
  5. ^ a b Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington. Bibcode:1953GCRV..C......0W.
  6. ^ a b Muterspaugh, Matthew W.; Hartkopf, William I.; Lane, Benjamin F.; o'Connell, J.; Williamson, M.; Kulkarni, S. R.; Konacki, Maciej; Burke, Bernard F.; Colavita, M. M.; Shao, M.; Wiktorowicz, Sloane J. (2010). "The Phases Differential Astrometry Data Archive. Ii. Updated Binary Star Orbits and a Long Period Eclipsing Binary". The Astronomical Journal. 140 (6): 1623. arXiv:1010.4043. Bibcode:2010AJ....140.1623M. doi:10.1088/0004-6256/140/6/1623.
  7. ^ "10 UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 27, 2019.
  8. ^ Bagnall, Philip M. (2012). The Star Atlas Companion: What You Need to Know about the Constellations. New York, New York: Springer. p. 281. ISBN 1-4614-0830-X.
  9. ^ Eggen, O. J. (June 1984). "A Systematic Search for Members of the Hyades Supercluster - Part Two - the Visual Binaries". Astronomical Journal. 89:6 (1541): 839. Bibcode:1984AJ.....89..839E. doi:10.1086/113579.

External links[]

Kaler, James B. "10 UMA (10 Ursae Majoris) = HR 3579 Lyncis". Stars. University of Illinois. Retrieved 9 March 2016.