11 Ursae Minoris

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11 Ursae Minoris
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ursa Minor
Right ascension 15h 17m 05.89s[1]
Declination +71° 49′ 26.0″[1]
Apparent magnitude (V) 5.024
Spectral type K4 III[2]
Apparent magnitude (B) 6.415
Apparent magnitude (J) 2.876
Apparent magnitude (H) 2.091
Apparent magnitude (K) 1.939
B−V color index 1.391
Radial velocity (Rv)–17.87 km/s
Proper motion (μ) RA: 3.97±0.23[1] mas/yr
Dec.: 9.65±0.21[1] mas/yr
Parallax (π)8.19 ± 0.19[1] mas
Distance398 ± 9 ly
(122 ± 3 pc)
Absolute magnitude (MV)–0.37[3]
Mass2.04±0.20[2] M
[2] R
Luminosity258.8±17.7[2] L
Surface gravity (log g)1.60[3] cgs
Temperature4358±59[2] K
Metallicity0.04 ± 0.04[3]
Age1.21±0.33[2] Gyr
Other designations
BD+72°678, GCRV 8864, HD 136726, HIP 74793, HR 5714, PPM 8870, SAO 8207
Database references
Exoplanet Archivedata
Extrasolar Planets

11 Ursae Minoris (11 UMi) is the Flamsteed designation of a 5th magnitude K-type giant star located approximately 398 light years away[1] in the constellation Ursa Minor. This star is twice as massive, 28 times bigger, and 258 times more luminous than the Sun.[2]

11 Ursae minoris is sometimes named Pherkard or Pherkad Minor, the later name to distinguish it from Pherkad (Major) which is γ Ursae minoris. It has also been designated as γ1 Ursae minoris, in which case the brighter Pherkad is called γ2 Ursae minoris, but these names are rarely used.[4]

11 Ursae minoris has a detected planet discovered in August 2009.[3]

Planetary system[edit]

11 Ursae minoris b was discovered during a radial velocity survey of 62 K type Red giant stars using the 2m Alfred Jensch telescope of the Thuringian State Observatory in Germany.[3]

The 11 Ursae Minoris planetary system[3]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b ≥10.50 ± 2.47 MJ 1.54 ± 0.07 516.22 ± 3.25 0.08 ± 0.03

See also[edit]


  1. ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b c d e f g Baines, Ellyn K.; et al. (2018). "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer". The Astronomical Journal. 155. 30. arXiv:1712.08109Freely accessible. Bibcode:2018AJ....155...30B. doi:10.3847/1538-3881/aa9d8b. 
  3. ^ a b c d e f Döllinger, P.; et al. (2009). "Planetary companions around the K giant stars 11 Ursae Minoris and HD 32518". Astronomy and Astrophysics. 505 (3): 1311–1317. arXiv:0908.1753Freely accessible. Bibcode:2009A&A...505.1311D. doi:10.1051/0004-6361/200911702. 
  4. ^ Kostjuk, N. D. (2004). "VizieR Online Data Catalog: HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index (Kostjuk, 2002)". VizieR On-line Data Catalog: IV/27A. Originally published in: Institute of Astronomy of Russian Academy of Sciences (2002). 4027. Bibcode:2004yCat.4027....0K. 

External links[edit]

Coordinates: Sky map 15h 17m 05.8886s, +71° 49′ 26.044″