Study of the TeV Emission from Mkn 501 with the Stereoscopic Cherenkov Telescope System of HEGRA

The HEGRA system of 4 Imaging Atmospheric Cherenkov Telescopes (IACTs) has been used since March 1997 for a comprehensive study of the gamma-ray emission from the BL Lac object Mkn 501 in the energy range above 500 GeV. Taking advantage of the unique capabilities of the IACT system, i.e. an unprecedented flux sensitivity in the TeV energy range and an unique energy resolution of better than 20% for individual TeV photons, detailed information about the temporal and spectral characteristics of the source during its spectacular bright phase in 1997 is reported. Further more, using the large HEGRA and Rossi X-Ray Timing Explorer All Sky Monitor (RXTE ASM) data bases, the correlation of the X-ray and the TeV activity of the source is discussed. Finally, an outlook over present and future activities is given.