8 Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus | 
| Right ascension | 19h 31m 46.32184s | 
| Declination | +34° 27′ 10.6874″ | 
| Apparent magnitude (V) | 4.75 | 
| Characteristics | |
| Spectral type | B3 IV | 
| B−V color index | −0.155 | 
| Astrometry | |
| Radial velocity (Rv) | −21.20±0.1 km/s | 
| Proper motion (μ) | RA: 1.16 mas/yr Dec.: −3.47 mas/yr | 
| Parallax (π) | 3.79±0.16 mas | 
| Distance | 860 ± 40 ly (260 ± 10 pc) | 
| Details | |
| Mass | 6.40 M☉ | 
| Radius | 6.50 R☉ | 
| Luminosity | 2,512 L☉ | 
| Surface gravity (log g) | 3.62 cgs | 
| Temperature | 16,100 K | 
| Metallicity [Fe/H] | +0.25 dex | 
| Rotational velocity (v sin i) | 15 km/s | 
| Other designations | |
| 8 Cygni, BD+34°3590, HD 184171, HIP 96052, HR 7426, SAO 68447. | |
| Database references | |
| SIMBAD | data | 
8 Cygni is a single star in the northern constellation of Cygnus. Based upon its parallax of 3.79 mas, 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. The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.
This is an aging subgiant star, as indicated by its spectral type of B3IV. Its effective 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 the Sun, and it is six times larger and many times brighter in comparison. The elemental abundances are near solar.