GS 2000+25
Near-infrared (I band) light curves for QZ Vulpeculae, adapted from Chevalier and Ilovaisky (1993). The data were collected over a 10 night period in July 1991. Data collected on different nights are plotted with different colors. The shape of the light curve changed over a period of approximately two days, leading to different shapes on even or odd numbered days. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 20h 02m 49.58s |
| Declination | +25° 14′ 11.3″ |
| Apparent magnitude (V) | 18.2 |
| Characteristics | |
| Spectral type | Black hole + K3-6 V |
| Astrometry | |
| Distance | 8800 ± 2300 ly (2700 ± 700 pc) |
| Orbit | |
| Period (P) | 8.26 hr |
| Details | |
| Black hole | |
| Mass | 7.2–7.8 M☉ |
| Other designations | |
| Nova Vul 1988, INTREF 1007, QZ Vul | |
| Database references | |
| SIMBAD | data |
GS 2000+25 is an X-ray binary system in the constellation Vulpecula, consisting of a late K-type star and a black hole. It is also an X-ray nova.
Fumiyoshi Makino and the Ginga satellite team discovered GS 2000+25, in April of 1988. A few days later a star, variable in visible light, was identified at its position. It received its variable star designation, QZ Vulpeculae, in 1989.