Observation data Epoch J2000 Equinox J2000 |
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Constellation | Ursa Minor |
Right ascension | 15h 44m 03.5193s[1] |
Declination | +77° 47′ 40.175″[1] |
Apparent magnitude (V) | +4.32[2] |
Characteristics | |
Spectral type | A3Vn[3] |
U−B color index | +0.05[2] |
B−V color index | +0.04[2] |
Astrometry | |
Radial velocity (Rv) | –13.1[4] km/s |
Proper motion (μ) | RA: 20.07[1] mas/yr Dec.: –2.50[1] mas/yr |
Parallax (π) | 8.68 ± 0.47[1] mas |
Distance | 380 ± 20 ly (115 ± 6 pc) |
Other designations | |
Zeta Ursae Minoris (ζ UMi, ζ Ursae Minoris) is a star in the constellation Ursa Minor. It has the traditional name Akhfa al Farkadain,[6] from the Arabic أخفى الفرقدين aḫfa al-farqadayn "the dimmer of the two calves", as opposed to Anwar al Farkadain (η UMi) "the brighter of the two calves". These names were originally applied to Pherkad and Kochab, respectively, the other two stars in the rectangle of Ursa Minor.
Zeta Ursae Minoris is a white stellar class A-type main sequence star with an apparent magnitude of +4.32. It is approximately 380 light years from Earth.
Despite its classification as a main sequence dwarf star, Zeta UMi is 3.4 times the mass of the sun and its luminosity is about 200 solar luminosities. At a surface temperature of 8,700 kelvins, this star is actually on the verge of becoming a giant star. Zeta UMi may also be a variable of the Delta Scuti type.
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