8 Cygni
Star in the constellation Cygnus
From Wikipedia, the free encyclopedia
8 Cygni is a single[7] 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. It is visible to the naked eye as a faint, bluish-white hued star with an apparent visual magnitude of about 4.7.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[4]
 | |
| 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 | B3 IV[3] |
| B−V color index | −0.155[2] |
| Astrometry | |
| Radial velocity (Rv) | −21.20±0.1[4] km/s |
| Proper motion (μ) | RA: 1.16[1] mas/yr Dec.: −3.47[1] mas/yr |
| Parallax (π) | 3.79±0.16 mas[1] |
| Distance | 860 ± 40 ly (260 ± 10 pc) |
| Absolute magnitude (MV) | −2.21[5] |
| Details | |
| Mass | 6.1[5] M☉ |
| Radius | 6.50[6] R☉ |
| Luminosity | 2,291[5] L☉ |
| Surface gravity (log g) | 3.58[5] cgs |
| Temperature | 16,300[5] K |
| Metallicity [Fe/H] | +0.25[6] dex |
| Rotational velocity (v sin i) | 55[5] km/s |
| Age | 53[5] Myr |
| Other designations | |
| 8 Cygni, BD+34°3590, HD 184171, HIP 96052, HR 7426, SAO 68447. | |
| Database references | |
| SIMBAD | data |
This is an aging subgiant star, as indicated by its spectral type of B3IV.[3] Its effective temperature of 16,300 K fits into the normal range of B-type stars: 11,000 to 25,000 K. 8 Cygni is about twice as hot as the Sun, and it is six times larger and many times brighter in comparison. The elemental abundances are near solar.[8]