OBSERVATIONS OF TEV GAMMA RAYS FROM MARKARIAN 501 AT LARGE ZENITH ANGLES

TeV gamma rays from the blazar Markarian 501 have been detected with the University of Durham Mark 6 atmospheric Cerenkov telescope using the imaging technique at large zenith angles. Observations were made at zenith angles in the range 70°-73° during July and August 1997 when Markarian 501 was undergoing a prolonged and strong flare.