11 Ursae Minoris is a single[6] star located approximately 410 light years away[1] in the northern circumpolar constellation of Ursa Minor. The star is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.15.[2] It is moving closer to the Earth with a heliocentric radial velocity of −17.5 km/s.[1]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Ursa Minor |
Right ascension | 15h 17m 05.89154s[1] |
Declination | +71° 49′ 26.0375″[1] |
Apparent magnitude (V) | 5.15[2] |
Characteristics | |
Spectral type | K4 III[3] |
Apparent magnitude (B) | 6.664[2] |
Apparent magnitude (J) | 2.657[2] |
Apparent magnitude (H) | 1.931±0.192[2] |
Apparent magnitude (K) | 1.701±0.198[2] |
B−V color index | 1.514±0.004[2] |
Astrometry | |
Radial velocity (Rv) | −17.52±0.15[1] km/s |
Proper motion (μ) | RA: 3.430[1] mas/yr Dec.: 10.113[1] mas/yr |
Parallax (π) | 7.9539 ± 0.1249 mas[1] |
Distance | 410 ± 6 ly (126 ± 2 pc) |
Absolute magnitude (MV) | –0.37[4] |
Details[3] | |
Mass | 2.04±0.20 M☉ |
Radius | 28.20+0.71 −0.73 R☉ |
Luminosity | 258.8±17.7 L☉ |
Surface gravity (log g) | 1.60[4] cgs |
Temperature | 4,358±59 K |
Metallicity | 0.04 ± 0.04[4] |
Age | 1.21±0.33 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
Extrasolar Planets Encyclopaedia | data |
This is an aging K-type giant star with a stellar classification of K4 III.[3] It is 1.2 billion years old with twice the mass of the Sun.[3] As a consequence of exhausting the hydrogen at its core, the star has expanded to 28 times the Sun's radius.[3] It is radiating 258 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,358 K.[3]
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.[7] 11 Ursae Minoris is the Flamsteed designation.
11 Ursae minoris has a detected planet discovered in August 2009.[4]
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.[4]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥10.50 ± 2.47 MJ | 1.54 ± 0.07 | 516.22 ± 3.25 | 0.08 ± 0.03 | — | — |
Constellation of Ursa Minor | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||
Stars |
| ||||||||||||
| |||||||||||||
Galaxies |
| ||||||||||||
| |||||||||||||
![]() |