Cygnus X-3
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cygnus | 
| Right ascension | 20h 32m 25.78s | 
| Declination | +40° 57′ 27.9″ | 
| Characteristics | |
| Spectral type | WN 4–6 | 
| Astrometry | |
| Radial velocity (Rv) | 208+113 −127 km/s | 
| Distance | 7,400±1,100 pc | 
| Absolute magnitude (MV) | −4.5 | 
| Orbit | |
| Period (P) | 4.8 hours | 
| Semi-amplitude (K1) (primary) | 379+124 −149 km/s | 
| Details | |
| WR | |
| Mass | 8–14 M☉ | 
| Radius | <2 R☉ | 
| Luminosity | 209,000+93,000 −64,000 L☉ | 
| Temperature | more than 80,000 K | 
| compact object | |
| Mass | 2.4+2.1 −1.1 M☉ | 
| Other designations | |
| V1521 Cyg, 18P 57, WR 145a, X Cyg X-3, RX J2032.3+4057, INTEGRAL1 118, 2U 2030+40, 3U 2030+40, 4U 2030+40 | |
| Database references | |
| SIMBAD | data | 
Cygnus X-3 is a high-mass X-ray binary (HMXB), one of the stronger binary X-ray sources in the sky. It is often considered to be a microquasar, and it is believed to be a compact object in a binary system which is pulling in a stream of gas from an ordinary star companion. It is one of only two known HMXBs containing a Wolf–Rayet star. It is invisible visually, but can be observed at radio, infrared, X-ray, and gamma-ray wavelengths.