Alkaid
Alkaid or Eta Ursae Majoris is a white star in the Ursa Major constellation.
Alkaid in the Big Dipper of Ursa Major. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 13h 47m 32.43776s[1] |
| Declination | +49° 18′ 47.7602″[1] |
| Apparent magnitude (V) | +1.86[2] |
| Characteristics | |
| Spectral type | B3 V[3] |
| U−B color index | –0.68[2] |
| B−V color index | –0.19[2] |
| Astrometry | |
| Radial velocity (Rv) | –10.9[4] km/s |
| Proper motion (μ) | RA: –121.17[1] mas/yr Dec.: –14.91[1] mas/yr |
| Parallax (π) | 31.38 ± 0.24[1] mas |
| Distance | 103.9 ± 0.8 ly (31.9 ± 0.2 pc) |
| Absolute magnitude (MV) | −0.67[5] |
| Details | |
| Mass | 6.1 ± 0.1[6] M☉ |
| Radius | 3.4[7] R☉ |
| Luminosity | 594 ± 31[8] L☉ |
| Surface gravity (log g) | 3.78[8] cgs |
| Temperature | 15,540 ± 1157[8] K |
| Rotational velocity (v sin i) | 150[9] km/s |
| Age | 10.0 ± 2.6[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, Floor (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600 Note: see VizieR catalogue I/311.
- ↑ 2.0 2.1 2.2 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
- ↑ Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333
- ↑ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, 35 (35): 1, Bibcode:1999VeARI..35....1W
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ↑ 6.0 6.1 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873
- ↑ Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189 (3): 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601
- ↑ 8.0 8.1 8.2 Baines, E.; Schmitt, H. R.; Zavala, R. T.; Hutter, D.; van Belle, G. T. (2017), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal, 155 (1): 30, arXiv:1712.08109, Bibcode:2018AJ....155...30B, doi:10.3847/1538-3881/aa9d8b, S2CID 119427037
- ↑ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590
- ↑ Rumrill, H. B. (1936). "Star Name Pronunciation". Publications of the Astronomical Society of the Pacific. 48 (283): 139. Bibcode:1936PASP...48..139R. doi:10.1086/124681. S2CID 120743052.
Other websites
- Alkaid at Jim Kaler's Stars website
