Omega2 Cygni
Omega2 Cygni, Latinized from ω2 Cygni, is the Bayer designation for a solitary star in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.5, which is faintly visible to the naked eye on a dark night. Based upon an annual parallax shift of 8.17 mas, it is located roughly 399 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.08 due to interstellar dust.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 31m 18.81663s |
| Declination | +49° 13′ 13.0656″ |
| Apparent magnitude (V) | 5.5292±0.0013 |
| Characteristics | |
| Spectral type | M2 III |
| Astrometry | |
| Radial velocity (Rv) | −64.15±0.20 km/s |
| Proper motion (μ) | RA: +9.21 mas/yr Dec.: −31.88 mas/yr |
| Parallax (π) | 8.17 ± 0.19 mas |
| Distance | 399 ± 9 ly (122 ± 3 pc) |
| Absolute magnitude (MV) | +0.00 |
| Details | |
| Luminosity | 301 L☉ |
| Temperature | 3,847 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a red giant star on the asymptotic giant branch, with a stellar classification of M2 III. It is a suspected variable star, although the evidence is considered "doubtful or erroneous". If it does exist, the variability is small with an amplitude of 0.05 magnitude and a timescale of around 30 days. There is a 58.3% chance that this star is a member of the Hercules stream.