Lambda Cephei
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 22h 11m 30.577s |
| Declination | +59° 24′ 52.154″ |
| Apparent magnitude (V) | +5.050 |
| Characteristics | |
| Evolutionary stage | Blue supergiant |
| Spectral type | O6.5If(n)p |
| U−B color index | −0.622 |
| B−V color index | +0.237 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −75.10 km/s |
| Proper motion (μ) | RA: −7.020 mas/yr Dec.: −10.812 mas/yr |
| Parallax (π) | 1.1761±0.0818 mas |
| Distance | 2,800 ± 200 ly (850 ± 60 pc) |
| Absolute magnitude (MV) | −6.43+0.11 −0.12 |
| Details | |
| Mass | 51.4+15.2 −12.0 M☉ |
| Radius | 18 – 21 R☉ |
| Luminosity | 630,000 L☉ |
| Surface gravity (log g) | 3.54 cgs |
| Temperature | 36,000 K |
| Rotational velocity (v sin i) | 210 km/s |
| Age | 4.0±0.2 Myr |
| Other designations | |
| Lambda Cephei, 22 Cephei, NSV 14069, BD+58 2402, GC 31066, HD 210839, HIP 109556, HR 8469, SAO 34149, GSC 03981-01585 | |
| Database references | |
| SIMBAD | data |
Lambda Cephei is a blue supergiant star in the northern constellation of Cepheus. Its name is a Bayer designation that is Latinized from λ Cephei, and is abbreviated Lambda Cep or λ Cep. This star is visible to the naked eye with an apparent visual magnitude of +5.050. Based on parallax measurements, it is located at a distance of approximately 2,800 light years. It is one of the hottest and most luminous stars visible to the naked eye.