Dubhe
Dubhe or Alpha Ursae Majoris is a red giant star in the constellation of Ursa Major. It is 27 times wider than the Sun.
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| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 11h 03m 43.67152s[1] |
| Declination | +61° 45′ 03.7249″[1] |
| Apparent magnitude (V) | 1.79[2] |
| Characteristics | |
| Spectral type | K0III[3] + F0V[4] |
| U−B color index | +0.93[2] |
| B−V color index | +1.07[2] |
| Variable type | Suspected[5] |
| Astrometry | |
| Radial velocity (Rv) | −9.4±0.3[6] km/s |
| Proper motion (μ) | RA: –134.11[1] mas/yr Dec.: –34.70[1] mas/yr |
| Parallax (π) | 26.54 ± 0.48[1] mas |
| Distance | 123 ± 2 ly (37.7 ± 0.7 pc) |
| Absolute magnitude (MV) | −1.10±0.04[7] |
| Details[8] | |
| α UMa A | |
| Mass | 3.44±0.11 M☉ |
| Radius | 17.03±0.13 R☉ |
| Luminosity | 165.1±8.3 L☉ |
| Surface gravity (log g) | 2.20 cgs |
| Temperature | 5,012±65 K |
| Metallicity [Fe/H] | −0.20±0.07[9] dex |
| Rotational velocity (v sin i) | 2.6±1.0[7] km/s |
| Age | 280±30 Myr |
| α UMa B | |
| Mass | ~1.6[3] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Dubhe Media
α Ursae Majoris A and faint companion binaries
A Hertzsprung–Russell diagram showing the position of Dubhe on the red-giant branch
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F.. Validation of the new Hipparcos reduction. Astronomy and Astrophysics 474 (2) (November 2007). p. 653–664. doi:10.1051/0004-6361:20078357.
- ↑ 2.0 2.1 2.2 Johnson, H. L.. UBVRIJKL photometry of the bright stars. Communications of the Lunar and Planetary Laboratory 4 (99) (1966). p. 99.
- ↑ 3.0 3.1 Guenther, D. B.. Evolutionary Model and Oscillation Frequencies for α Ursae Majoris: A Comparison with Observations. The Astrophysical Journal 530 (1) (2000). p. L45–L48. doi:10.1086/312473.
- ↑ Tokovinin, A. A.. MSC - a catalogue of physical multiple stars. Astronomy and Astrophysics Supplement Series 124 (1997). p. 75–84. doi:10.1051/aas:1997181.
- ↑ Samus, N. N.. VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013). VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1 (2009).
- ↑ Gontcharov, G. A.. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system. Astronomy Letters 32 (11) (November 2006). p. 759–771. doi:10.1134/S1063773706110065.
- ↑ 7.0 7.1 Carney, Bruce W.. Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars. The Astronomical Journal 135 (3) (March 2008). p. 892–906. doi:10.1088/0004-6256/135/3/892.
- ↑ Baines, E.. Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer. The Astronomical Journal 155 (1) (2017). p. 30. doi:10.3847/1538-3881/aa9d8b.
- ↑ McWilliam, Andrew. High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances. Astrophysical Journal Supplement Series 74 (December 1990). p. 1075–1128. doi:10.1086/191527.
- ↑ DUBHE -- Spectroscopic binary. SIMBADCentre de Données astronomiques de Strasbourg. Retrieved 2011-12-23.
