Omega1 Cygni
B-type subgiant star in the constellation Cygnus
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Omega1 Cygni, Latinized from ω1 Cygni, is the Bayer designation for a solitary[13] star in the northern constellation of Cygnus. It is visible to the naked eye with an apparent visual magnitude of 4.94.[4] Based upon an annual parallax shift of 2.59 mas,[7] it is estimated to lie roughly 1,260 light years from the Sun. Relative to its neighbors, this star has a peculiar velocity of 25.7±2.2 km/s.[6]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 30m 03.54116s[1] |
| Declination | +48° 57′ 05.6446″[1] |
| Apparent magnitude (V) | +4.93 - 4.96[2] |
| Characteristics | |
| Spectral type | B2.5 IV[3] |
| U−B color index | −0.68[4] |
| B−V color index | −0.09[4] |
| Variable type | β Cep[5] (λ Eri[2]) |
| Astrometry | |
| Radial velocity (Rv) | −21.9±2.0[6] km/s |
| Proper motion (μ) | RA: +10.883[7] mas/yr Dec.: +7.057[7] mas/yr |
| Parallax (π) | 2.5878±0.1637 mas[7] |
| Distance | 1,260 ± 80 ly (390 ± 20 pc) |
| Absolute magnitude (MV) | −2.65[8] |
| Details | |
| Mass | 8.1±0.2[3] M☉ |
| Radius | 4.55[9][a] R☉ |
| Luminosity | 1,549[9] L☉ |
| Surface gravity (log g) | 2.312[10] cgs |
| Temperature | 16,982[9] K |
| Metallicity [Fe/H] | 0.0[8] dex |
| Rotational velocity (v sin i) | 145[11] km/s |
| Age | 33.2±4.5[3] Myr |
| Other designations | |
| ω1 Cyg, 45 Cygni, BD+48°3142, FK5 3641, HD 195556, HIP 101138, HR 7844, SAO 49712, V2014 Cygni[12] | |
| Database references | |
| SIMBAD | data |
This is a somewhat evolved B-type subgiant star with a stellar classification of B2.5 IV.[3] Telting and colleagues report it as a Beta Cephei variable with a high degree of confidence as they found regular pulsations in its spectrum in a high-resolution spectroscopy study published in 2006.[5] Its brightness varies irregularly by 0.034 magnitude every 1.137 days.[15]
Notes
- Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
