COMPTEL OVERVIEW - ACHIEVEMENTS AND EXPECTATIONS

The Imaging Compton Telescope (COMPTEL) aboard NASA's Compton Gamma-Ra y Observatory has opened the 1 to 30 MeV gamma-ray energy range as a n ew window to astronomy. The first-ever broadband all-sky maps in this energy range now exist. A variety of gamma-ray emitting objects are vi sible, namely spin-down pulsars, stellar black-hole candidates, supern ova remnants, extended regions of interstellar space, nuclei of active galaxies, gamma-ray bursts, and the Sun during solar flares. Moreover , the MeV range is rich in gamma-ray lines. Here, COMPTEL has achieved a major breakthrough by generating the first all-sky map of the 1.8 M eV line from radioactive Al-26. In addition, COMPTEL succeeded in the first detection of the 1.156 MeV Line from radioactive Ti-44 from a su pernova remnant (Cas A), and - again for the first time - detected MeV emission from the Orion complex that can be ascribed to nuclear inter action lines from excited C-12 and O-16 nuclei. Recently, indications of two Co-56 lines at 847 and 1.238 MeV were found in the measurement of SN 1991T.