8 Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 31m 46.32184s[1] |
| Declination | +34° 27′ 10.6874″[1] |
| Apparent magnitude (V) | 4.75[2] |
| Characteristics | |
| Spectral type | B3IV |
| U−B color index | −0.66 |
| B−V color index | −0.155[2] |
| Astrometry | |
| Radial velocity (Rv) | −21.20 ± 0.1[3] km/s |
| Proper motion (μ) | RA: 1.16[1] mas/yr Dec.: −3.47[1] mas/yr |
| Parallax (π) | 3.79 ± 0.16[1] mas |
| Distance | 860 ± 40 ly (260 ± 10 pc) |
| Details | |
| Mass | 6.40[4] M☉ |
| Radius | 6.50[4] R☉ |
| Luminosity | 2,512[4] L☉ |
| Surface gravity (log g) | 3.62[4] cgs |
| Temperature | 16,100[4] K |
| Metallicity [Fe/H] | +0.25[4] dex |
| Rotational velocity (v sin i) | 15[5] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
8 Cygni is a star in the northern constellation of Cygnus. Based upon its parallax of 3.79 mas,[1] it is approximately 860 light-years (260 parsecs) away from Earth. Its apparent magnitude is about 4.7,[2] making it faintly visible to the naked eye.
8 Cygni is a bluish-white subgiant star, as indicated by its spectral type of B3IV. Therefore, its surface temperature of 16,100 K fits into the normal range of B-type stars: 11,000 to 25,000 K. 8 Cygni is about twice as hot as that of the Sun, and it is larger and many times brighter in comparison.[4]
References
- 1 2 3 4 5 6 van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- 1 2 3 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV data. Bibcode:1986EgUBV........0M.
- ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
- 1 2 3 4 5 6 7 Challouf, M.; et al. (2014), "Improving the surface brightness-color relation for early-type stars using optical interferometry⋆", Astronomy & Astrophysics, 570: A104, arXiv:1409.1351, Bibcode:2014A&A...570A.104C, doi:10.1051/0004-6361/201423772.
- ↑ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573: 359. Bibcode:2002ApJ...573..359A. doi:10.1086/340590.
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