VLA , MERLIN and Hubble Space Telescope imaging observations of the extended regions of the symbiotic system CH Cygni are analysed .
These extensions are evidence of a strong collimation mechanism , probably an accretion disk surrounding the hot component of the system .
Over 16 years ( between 1985 and 2001 ) the general trend is that these jets are seen to precess .
Fitting a simple ballistic model of matter ejection to the geometry of the extended regions suggests a period of 6520 \pm 150 days , with a precession cone opening angle of 35 \pm 1 degrees .
This period is of the same order as that proposed for the orbital period of the outer giant in the system , suggesting a possible link between the two .
Anomalous knots in the emission , not explained by the simple model , are believed to be the result of older , slower moving ejecta , or possibly jet material that has become disrupted through sideways interaction with the surrounding medium .