摘要
Ⅰ. INTRODUCTIONThe supernova remnant (SNR) G78.2+2.1 is situated in the complicated Cygnus X region. It is rather difficult to identify this SNR, because while observing this SNR the observer’s sight line passes through the Orion arm. The star γ Cygni is in the region of SNR, but it is generally agreed that the star γ Cygni is a foreground object. A small, bright optical nebulosity, very close to the star γ Cygni, has been shown to resemble a normal H Ⅱ region, but we cannot neglect the relationship
