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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 mas[1] |
| 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 |
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
edit- ^ 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 e f g h i j k l Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ^ a b 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.
- ^ 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 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.
- ^ a b Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
- ^ De Medeiros, J. R.; et al. (November 2000), "Rotation and lithium in single giant stars", Astronomy and Astrophysics, 363: 239–243, arXiv:astro-ph/0010273, Bibcode:2000A&A...363..239D.
- ^ "5 UMi". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-04-02.
- ^ 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, Bibcode:1983ApJ...268..264M, doi:10.1086/160951.
- ^ Brown, Jeffery A.; et al. (October 1989), "A search for lithium-rich giant stars", Astrophysical Journal Supplement Series, 71: 293–322, Bibcode:1989ApJS...71..293B, doi:10.1086/191375.