| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 17h45m 39.73s[1] |
| Declination | −29° 00′ 29.7″[1] |
| Distance | 26,000 ly (8,000[2] pc) |
| Other designations | |
WR 101f | |
| Database references | |
| SIMBAD | data |
GCIRS 13E is an infrared and radio object near the Galactic Center. It is believed to be a cluster of hot massive stars, possibly containing an intermediate-mass black hole (IMBH) at its center.
GCIRS 13E was first identified as GCIRS 13, which was later resolved into two components GCIRS13E and W.[3] GCIRS 13E was initially modelled as a single object, possibly a binary system.[4] It was even classified as a Wolf-Rayet star because of its strong emission line spectrum, and named WR 101f.[5] It was then resolved into seven Wolf-Rayet and class O stars.[6] The highest-resolution infrared imaging and spectroscopy can now identify 19 objects in GCIRS 13E, of which 15 are dense gaseous regions. The remaining four objects are stars: WN8 and WC9 Wolf-Rayet stars; an OB supergiant; and a K3 giant.[2]
The motions of the members of GCIRS 13E appear to indicate a much higher mass than can be accounted for by the visible objects. It has been proposed that there may be an intermediate-mass black hole with a mass of about 1,300 M☉ at its center. There are a number of problems with this theory.[7] However, the true nature of the cluster remains unknown.[2]
GCIRS 13E is a small cluster dominated by a few massive stars. It is thought that massive stars cannot form so close to a supermassive black hole and since such massive stars have a short lifespan it is thought that GCIRS 13E must have migrated inward toward the central black hole within the past 10 million years, probably from about 60 light-years further out than its current orbit. The stars are possibly the remains of a globular cluster where a middleweight black hole could develop through runaway star collisions.[7] GCIRS 13E could also be a dark star cluster which forms in the inner Galaxy if the evaporation rate of stars from the cluster is faster due to a strong tidal field than the depletion of the black hole content though ejections.[8]
