P Cygni
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 17m 47.2020s |
| Declination | +38° 01′ 58.549″ |
| Apparent magnitude (V) | 4.82 (3 to 6) |
| Characteristics | |
| Spectral type | B1-2 Ia-0ep (B1 Iapeq) |
| U−B color index | −0.58 |
| B−V color index | +0.42 |
| Variable type | LBV |
| Astrometry | |
| Radial velocity (Rv) | −8.9 km/s |
| Proper motion (μ) | RA: −3.723 mas/yr Dec.: −6.798 mas/yr |
| Parallax (π) | 0.6251±0.0729 mas |
| Distance | 5,300±590 ly (1,610±180 pc) |
| Absolute magnitude (MV) | −7.9 |
| Details | |
| Mass | 37 M☉ |
| Radius | 76 R☉ |
| Luminosity | 610,000 L☉ |
| Surface gravity (log g) | 2.25 cgs |
| Temperature | 18,700 K |
| Metallicity | 0.29 He/H |
| Rotational velocity (v sin i) | 35 km/s |
| Other designations | |
| Nova Cyg 1600, 34 Cyg, JP11 3218, TD1 26474, GSC 03151-03442, TYC 3151-3442-1, AG+37°1953, 2MASS J20174719+3801585, ALS 11097, HD 193237, MCW 849, BD+37°3871, Hen 3-1871, PLX 4837, CEL 5017, PPM 84645, P Cyg, RAFGL 5493S, GC 28218, HIP 100044, ROT 2959, GCRV 12673, HR 7763, SAO 69773, AAVSO 2014+37A | |
| Database references | |
| SIMBAD | data |
P Cygni (34 Cygni) is a variable star in the constellation Cygnus. The designation "P" was originally assigned by Johann Bayer in Uranometria as a nova. Located about 5,300 light-years (1,560 parsecs) from Earth, it is a hypergiant luminous blue variable (LBV) star of spectral type B1-2 Ia-0ep that is one of the most luminous stars in the Milky Way.