4_Ursae_Minoris

4 Ursae Minoris

4 Ursae Minoris

Binary star system in the constellation Ursa Minor

4 Ursae Minoris is a binary star[6] system in the northern circumpolar constellation Ursa Minor. It is faintly visible to the naked eye with an apparent visual magnitude of 4.80.[2] Based upon an annual parallax shift of 7.14±0.42 mas[1] as seen from Earth's orbit, it is located roughly 460 light years from the Sun. It is moving further away with a heliocentric radial velocity of +5.9 km/s.[5]

Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...

This is a single-lined spectroscopic binary star system with an orbital period of 1.66 years and an eccentricity of 0.14.[7][6] The primary is a red giant of spectral type K3-IIIb Fe-0.5,[3] a star that has used up its core hydrogen and is expanding. The suffix notation indicates the spectrum displays a mild underabundance of iron for a star of its type. It has expanded to around 28[8] times the Sun's radius and is radiating 437[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,165 K.[9]

References

  1. [1]
    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.
  2. [2]
    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.
  3. [3]
    Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
  4. [4]
    Ryon, Jenna; et al. (August 2009), "Comparing the Ca ii H and K Emission Lines in Red Giant Stars", Publications of the Astronomical Society of the Pacific, 121 (882): 842, arXiv:0907.3346, Bibcode:2009PASP..121..842R, doi:10.1086/605456, S2CID 17821279.
  5. [5]
    De Bruijne, J. H. J.; Eilers, A.-C. (2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: A61, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347.
  6. [6]
    Scarfe, C. D. (1971), "A Revised Orbit for 4 Ursae Minoris", Publications of the Astronomical Society of the Pacific, 83 (496): 807, Bibcode:1971PASP...83..807S, doi:10.1086/129218.
  7. [7]
    Ren, Shulin; Fu, Yanning (March 2013), "Hipparcos Photocentric Orbits of 72 Single-lined Spectroscopic Binaries", The Astronomical Journal, 145 (3): 7, Bibcode:2013AJ....145...81R, doi:10.1088/0004-6256/145/3/81, S2CID 120199240, 81.
  8. [8]
    Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (2) (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  9. [9]
    Koleva, M.; Vazdekis, A. (February 2012), "Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library", Astronomy & Astrophysics, 538: 13, arXiv:1111.5449, Bibcode:2012A&A...538A.143K, doi:10.1051/0004-6361/201118065, S2CID 53999614, A143.
  10. [10]
    "4 UMi". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-04-02.
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