22 Cygni
22 Cygni is a binary star system in the northern constellation of Cygnus. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.95. The annual shift of 3.0 mas yields a distance estimate of around 1,070 light years. It is moving closer to the Earth with a heliocentric radial velocity of −15 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 55m 51.75718s |
| Declination | +38° 29′ 12.154″ |
| Apparent magnitude (V) | 4.95 |
| Characteristics | |
| Spectral type | B5 IV |
| B−V color index | −0.086±0.009 |
| Astrometry | |
| Radial velocity (Rv) | −14.8±2.2 km/s |
| Proper motion (μ) | RA: +6.559 mas/yr Dec.: −0.469 mas/yr |
| Parallax (π) | 3.0418 ± 0.2388 mas |
| Distance | 1,070 ± 80 ly (330 ± 30 pc) |
| Absolute magnitude (MV) | −3.18 |
| Orbit | |
| Period (P) | 78.2±0.4 d |
| Eccentricity (e) | 0.17±0.13 |
| Periastron epoch (T) | 2443734.5±2.1 JD |
| Argument of periastron (ω) (secondary) | 139±11° |
| Semi-amplitude (K1) (primary) | 20.7±3.1 km/s |
| Details | |
| 22 Cyg A | |
| Mass | 7.9±0.4 M☉ |
| Radius | 5.6 R☉ |
| Luminosity | 7,305 L☉ |
| Surface gravity (log g) | 3.35 cgs |
| Temperature | 15,200 K |
| Rotational velocity (v sin i) | 30 km/s |
| Age | 37.3±4.2 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a single-lined spectroscopic binary with an orbital period of 78.2 days and an eccentricity of roughly 0.17. The visible component has a stellar classification of B5 IV that matches a B-type subgiant star. It is 37 million years old with a projected rotational velocity of 30 km/s and has an essentially solar metallicity, within the margin of error. The star has eight times the mass of the Sun and about 5.6 times the Sun's radius. It is radiating 7,305 times the Sun's luminosity from its photosphere at an effective temperature of 15,200 K.