There has been a recent suggestion that Cyg X-3 contains a black hole ( BH ) of mass M _ { 1 } \sim 17 M _ { \odot } .
This interpretation is closely linked to a previous claim that Cyg X-3 contains a Wolf-Rayet star of mass M _ { 2 } \sim 10 M _ { \odot } .
The latter interpretation would imply that the X-ray source in this close binary ( P = 4.8 hr ) is enshrouded by a relatively cool superstrong wind with { \dot { M } } \geq 10 ^ { -5 } ~ { } M _ { \odot } yr ^ { -1 } .
It can be shown that such a wind would be completely opaque to the low energy X-rays observed from the source and hence the Wolf-Rayet hypothesis can not be a correct one .
By pursuing the same argument it also follows that the compact object must be of modest mass ruling out the existence of a massive BH in Cyg X-3 .
Note , however , that at present we can not strictly rule out the probable existence of stellar mass BH in Cyg X-3 or any other X-ray binary which are believed to contain a neutron star as the compact object .
Yet , a more probable scenario for Cyg X-3 would be one where the compact object is a canonical neutron star ( NS ) and the companion is an extremely low mass dwarf , M _ { 2 } \sim 10 ^ { -2 } ~ { } M _ { \odot } much like PSR~ { } 1957 + 20 .