Astronomy:5 Ursae Minoris
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ursa Minor |
| Right ascension | 14h 27m 31.54335s[1] |
| Declination | +75° 41′ 45.5717″[1] |
| Apparent magnitude (V) | 4.253[2] |
| Characteristics | |
| Spectral type | K4-III[3] |
| B−V color index | 1.457[2] |
| Astrometry | |
| Radial velocity (Rv) | +9.34[2] km/s |
| Proper motion (μ) | RA: +8.79[1] mas/yr Dec.: +21.76[1] mas/yr |
| Parallax (π) | 9.09 ± 0.13[1] mas |
| Distance | 359 ± 5 ly (110 ± 2 pc) |
| Absolute magnitude (MV) | −0.96[4] |
| Details | |
| Mass | 1.86[2] M☉ |
| Radius | 16[5] R☉ |
| Luminosity | 447[2] L☉ |
| Surface gravity (log g) | 1.91[6] cgs |
| Temperature | 4,095±39[2] K |
| Metallicity [Fe/H] | −0.16[6] dex |
| Rotational velocity (v sin i) | 1.9[7] km/s |
| Age | 2.00[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
5 Ursae Minoris is a star in the circumpolar constellation of Ursa Minor. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.253.[2] The distance to this star, as determined from an annual parallax shift of 9.09±0.13 mas,[1] is about 110 pc. It is moving further away with a heliocentric radial velocity of +9 km/s.[2]
With an age of around two billion years, this is an evolved red giant with a stellar classification of K4-III;[3] a star that has used up its core hydrogen and has expanded. It is a mild barium star, which may indicate it is a binary with a white dwarf companion,[9] and is very lithium-weak.[10] The star has an estimated 1.86[2] times the mass of the Sun and has expanded to about 16[5] times the Sun's radius. It is radiating 447[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,095 K.[2]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 5.0 5.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ 6.0 6.1 Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode: 2010A&A...515A.111S.
- ↑ De Medeiros, J. R. et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics 363: 239–243, Bibcode: 2000A&A...363..239D.
- ↑ "5 UMi". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=5+UMi.
- ↑ McClure, R. D. (May 1, 1983), "The binary nature of the barium stars. II - Velocities, binary frequency, and preliminary orbits", Astrophysical Journal, Part 1 268: 264–273, doi:10.1086/160951, Bibcode: 1983ApJ...268..264M.
- ↑ Brown, Jeffery A. et al. (October 1989), "A search for lithium-rich giant stars", Astrophysical Journal Supplement Series 71: 293–322, doi:10.1086/191375, Bibcode: 1989ApJS...71..293B.
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