Locating very high energy γ-ray sources with arc minute accuracy.

The angular accuracy of γ-ray detectors is intrinsically limited by the physical processes involved in photon detection. Although a number of point-like sources were detected by the COS-B satellite, only two have been unambiguously identified by time signature with counterparts at longer wavelengths. By taking advantage of the extended longitudinal structure of VHE γ-ray showers, measurements in the TeV energy range can pinpoint source coordinates to arc minute accuracy. This has now been demonstrated with new data analysis prodecures applied to observations of the Crab Nebula using Čerenkov air shower imaging techniques.