| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h 31m 46.359s |
| Declination | +54° 31′ 20.23″ |
| Apparent magnitude (V) | 4.772 (5.33 / 5.62) |
| Characteristics | |
| Spectral type | B7.5V/B8.5V |
| U−B color index | −0.35 |
| B−V color index | −0.10 |
| Variable type | none |
| Astrometry | |
| Radial velocity (Rv) | -12.20 ± 1.3 km/s |
| Proper motion (μ) |
RA: 41.20 ± 0.29 mas/yr Dec.: −16.54 ± 0.35 mas/yr |
| Parallax (π) | 8.64 ± 0.43mas |
| Distance | 380 ± 20 ly (116 ± 6 pc) |
| Absolute magnitude (MV) | +0.3/+0.6 |
| Orbit | |
| Period (P) | 245.70 ± 35.96 yr |
| Semi-major axis (a) | 0.448 ± 0.028″ |
| Eccentricity (e) | 0.689 ± 0.119 |
| Inclination (i) | 53.6 ± 5.2° |
| Longitude of the node (Ω) | 17.6 ± 9.6° |
| Periastron epoch (T) | 2025.54 ± 4.56 |
|
Argument of periastron (ω) (secondary) |
301.0 ± 2.6° |
| Other designations | |
| Database references | |
| SIMBAD | λ Cas |
| λ Cas A | |
| λ Cas B | |
Lambda Cassiopeiae (λ Cas, λ Cassiopeiae) is a binary star in the constellation Cassiopeia. The system has a combined apparent magnitude of +4.74 and is approximately 380 light years from Earth.
Both components are blue-white B-type main sequence dwarfs. The brighter, λ Cassiopeiae A, has an apparent magnitude of +5.5, while its companion, λ Cassiopeiae B, has an apparent magnitude of +5.8. The two stars are separated by 0.6 arcseconds and complete one orbit around their common centre of mass once every 250 years.