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[3] mas |
| 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 UMi, δ Ursae Minoris; also 23 UMi) is a star in the constellation Ursa Minor. It has the traditional name Yildun (also spelled Vildiur, Jildun, Gildun, and Yilduz), from the Turkish yıldız "star". It may also have been called Pherkard, an alternate spelling of Pherkad, used for γ UMi and 11 UMi.
Delta Ursae Minoris is a white A-type main sequence dwarf with an apparent magnitude of +4.35 approximately 172 light years from Earth.[2]
In science fiction
The star is mentioned in the Honorverse, a series of military science fiction novels written by David Weber, as the headquarters of Technodyne Industries of Yildun, a major Solarian League shipbuilding corporation with rather questionable ethics (e.g. business ties with Manpower Incorporated and Jessyk Combine, both of Mesa), though the star system is described as including only a (highly mineral-and-metals-rich) asteroid belt.
References
- 1 2 3 4 5 Jim Kaler. "YILDUN (Delta Ursae Minoris)". Stars.astro.illinois.edu. Retrieved 2012-03-05.
- 1 2 3 4 5 6 "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.
External links
- Delta Ursae Minoris on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
| ||||||||||||||||||||||||||||||