Long-term observations of galaxy 3C 66A

Monitoring of the active galaxy nucleus 3C 66A in the VHE γ-ray and analysis of data in X-rays and optical ranges over the period 1996–2009 were carried out. The nature of processes responsible for one or another type of radiation appeared to be very complicated since, at certain periods of time, an either positive or negative correlation may be observed between different types of radiation. Period of radiation P = 365 days in the X-ray range was found.