The intermediate-frequency peaked BL Lacertae ( IBL ) object 3C 66A is detected during 2007 - 2008 in VHE ( very high energy : E > 100 GeV ) \gamma -rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov telescopes .
An excess of 1791 events is detected , corresponding to a significance of 21.2 standard deviations ( \sigma ) , in these observations ( 32.8 hours live time ) .
The observed integral flux above 200 GeV is 6 % of the Crab Nebula ’ s flux and shows evidence for variability on the time-scale of days .
The measured energy spectrum is characterized by a soft power law with photon index \Gamma = 4.1 \pm 0.4 _ { stat } \pm 0.6 _ { sys } .
The radio galaxy 3C 66B is excluded as a possible source of the VHE emission .