Polaris, a white supergiant star in Ursa Minor
Polaris is a white supergiant star in the constellation Ursa Minor. At 432 light years away, it is the 47th brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 1.97.
Polaris (HIP 11767)
Polaris is a white supergiant star in the constellation Ursa Minor. At 432 light years away, it is the 47th brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 1.97. Polaris is the primary component of a multiple-star system and an intrinsic variable star that varies between magntitudes 2.09 and 2.13 over a period of 3.97 days. The iron abundance of Polaris is +0.13 (134.9% of the Sun). It is moving through the Galaxy at a speed of 33.3 km/s relative to the Sun. Its projected Galactic orbit carries it between 18,600 and 24,400 light years from the center of the Galaxy.
Sky position: RA 2h 31.8m, Dec +89° 15.6'
Common designations: Polaris, Alpha Ursae Minoris, 1 Ursae Minoris, HIP 11767, HD 8890
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Brightest stars in Ursa Minor:
(list all)
1
| 1.97
) Polaris
| Rank | Mag. | Star |
| 2 | 2.07 | Kochab |
| 3 | 3.00 | Pherkad |
| 4 | 4.21 | Epsilon Ursae Minoris |
| 5 | 4.25 | 5 Ursae Minoris |
| 6 | 4.29 | Zeta Ursae Minoris |
| 7 | 4.35 | Yildun |
| 8 | 4.63 | RR Ursae Minoris |
| 9 | 4.80 | 4 Ursae Minoris |
| 10 | 4.95 | Eta Ursae Minoris |
| 11 | 5.00 | Theta Ursae Minoris |
| 12 | 5.02 | Pherkad Minor |
| 13 | 5.15 | Gliese 580.2 |
| 14 | 5.18 | HR 5334 |
| 15 | 5.48 | 19 Ursae Minoris |
| 16 | 5.50 | HR 5139 |
| 17 | 5.55 | HR 6173 |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Polaris
(compared to the Sun)
E
ccentricity: 13.3% vs. 16.0%Angle φ : -173.6°vs. 26.0°
Semi-major axis : 6,596 pc vs. 8,686 pc
Semi-minor axis: 6,537 pc vs. 8,574 pc
Focus-to-center
: 878 pcvs. 1,388 pcSemilatus rectum : 6,479 pc vs. 8,464 pc
Perigalacticon: 5,718 pc vs. 7,297 pc
Apogalacticon
: 7,473 pcvs. 10,074 pcSome Tabulated XHIP Data for Polaris
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 37.94614300° ±0.09 mas | 44.48 ±0.11 mas/yr. |
| Declination: | 89.26413778° ±0.10 mas | -11.85 ±0.13 mas/yr. |
| Galactic Longitude: | 123.28042130° | 45.33 mas/yr. |
| Galactic Latitude: | 26.46137410° | 8.00 mas/yr. |
Parallax: 7.54 ± 0.11 mas
Spectrography
Spectral Type: F8Ib 1993ASPC...45...59L.
Radial Velocity:
-16.42 ±0.03 km/s [A rating]
2004A&A...424..727P.
This star is a spectroscopic binary with a solved orbit.
Iron Abundance [Fe/H]:
0.13 dex
2011A&A...525A..71W.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 2.61 | -3.01 |
| V | 1.97 | -3.64 |
| R | ||
| I | 1.37 | -4.25 |
| J | ||
| H | ||
| K |
B-V: +0.64 V-I: +0.60
Derivations
Heliocentric distance: 132.59 pc (1.5% margin of error)
Galactocentric distance: 7,466 pc
Transverse velocity: 28.9 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -65.1 pc | 99.2 pc | 59.1 pc |
| Velocity (U, V, W) | -14.5 km/s | -29.8 km/s | -2.8 km/s |