BG Geminorum
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Gemini |
| Right ascension | 06h 03m 30.81s |
| Declination | +27° 41′ 50.6″ |
| Apparent magnitude (V) | 12.9 - 13.6 |
| Characteristics | |
| Spectral type | K0I |
| Apparent magnitude (g) | 12.83 |
| Variable type | eclipsing |
| Astrometry | |
| Proper motion (μ) | RA: 0.209±0.021 mas/yr Dec.: −0.385±0.015 mas/yr |
| Parallax (π) | 0.2057±0.0197 mas |
| Distance | 16,000 ± 2,000 ly (4,900 ± 500 pc) |
| Orbit | |
| Period (P) | 91.645 days |
| Semi-major axis (a) | >0.63 ± 0.04 AU |
| Inclination (i) | >80° |
| Details | |
| Supergiant | |
| Mass | >0.7 M☉ |
| Temperature | 4,500 K |
| Black hole or class B | |
| Mass | >3.5 M☉ |
| Other designations | |
| BG Geminorum, 2MASS J06033081+2741506 | |
| Database references | |
| SIMBAD | data |
BG Geminorum is an eclipsing binary star system in the constellation Gemini. It consists of a K0 supergiant with a more massive but unseen companion. The companion is likely to be either a black hole or class B star. Material from the K0 star is being transferred to an accretion disk surrounding the unidentified object.