SIMBAD references

We have discovered extended X-ray emission from the microquasar Cygnus X-3 in archival Chandra X-Ray Observatory observations. A 5" wide structure lies approximately 16" to the northeast from the core point source and may be extended in that direction. This angular scale corresponds to a physical extent of roughly 0.8 lt-yr, at a distance of 2.5 lt-yr from Cyg X-3 (assuming a 10 kpc distance). The flux varied by a factor of 2.5 during the 4 months separating two of the observations, indicating significant substructure. The peak 2-10 keV luminosity was ∼5x10³⁴ ergs/s. There may also be weaker, extended emission of similar scale oppositely directed from the core, suggesting a bipolar outflow. This structure is not part of the dust-scattering halo, nor is it caused by the Chandra point-spread function. In this Letter, we describe the observations and discuss possible origins of the extension.