We have observed a number of minor radio flares in Cyg X-3 using the MERLIN array .
Photometric observations show the system to be highly active with multiple flares on hourly timescales over the one month observing programme .
Analysis of the source ’ s power spectrum show no persistent periodicities in these data , and no evidence of the 4.8 hr orbital period .
An upper limit of 15 mJy can be placed on the amplitude of any sinusoidal varaition of source flux at the orbital period .
The brightness temperature of a flare is typically T _ { b } \geq 10 ^ { 9 } - 10 ^ { 10 } K , with a number of small flares of 5 minute duration having brightness temperatures of T _ { b } \geq { few } \times 10 ^ { 11 } K. For such a change in flux to occur within a typical 10 minute timescale , the radiation must originate from plasmons with a size \leq 1.22 AU .
This emission is unlikely to originate close to the centre of the system as both the jets and compact object are buried deep within an optically thick stellar wind .
Assuming a spherically symmetric wind , plasmons would become visible at distances \sim 13 AU from the core .