Delta Ursae Minoris
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Minor[1] |
| Right ascension | 17h 32m 12.9s[2] |
| Declination | 86° 35′ 11.25″[2] |
| Apparent magnitude (V) | 4.35[2] |
| Characteristics | |
| Spectral type | A1Vn[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.6[2] km/s |
| Parallax (π) | 18.95 ± 0.14 mas[3] |
| Distance | 172 ± 1 ly (52.8 ± 0.4 pc) |
| Absolute magnitude (MV) | 0.62[4] |
| Details | |
| Radius | 2.8[1] R☉ |
| Luminosity | 47[1] L☉ |
| Temperature | 9000[1] K |
| Rotation | 19 hours[1] |
| Other designations | |
Delta Ursae Minoris (δ Ursae Minoris, abbreviated Delta UMi, δ UMi), also named Yildun,[5] is a star in the constellation of Ursa Minor.
Delta Ursae Minoris is a white A-type main sequence dwarf with an apparent magnitude of +4.35 approximately 172 light years from the Sun.[2]
Nomenclature
δ Ursae Minoris (Latinised to Delta Ursae Minoris) is the star's Bayer designation.
It bore the traditional name Yildun (also spelled Vildiur, Jildun, Gildun, and Yilduz) from the Turkish yıldız "star". It may also[citation needed] have been called Pherkard, an alternate spelling of Pherkad, used for Gamma Ursae Minoris and 11 Ursae Minoris. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[6] to catalogue and standardize proper names for stars. The WGSN approved the name Yildun for this star on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.[5]
References
- ^ a b c d e Jim Kaler. "YILDUN (Delta Ursae Minoris)". Stars.astro.illinois.edu. Retrieved 2012-03-05.
- ^ a b c d e f "Delta Ursae Minoris". SIMBAD Astronomical Database. Retrieved 2012-03-04.
- ^ van Leeuwen, F. (November 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
- ^ Jim Kaler. "The Polar Project". University of Illinois. Retrieved 2012-03-04.
- ^ a b "IAU Catalog of Star Names". Retrieved 28 July 2016.
- ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
External links
- Delta Ursae Minoris on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
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