0420008

The Orion region hosts one of the most nearby regions of recent massive-star formation. COMPTELs measurement of 1809 keV emission from this region shows an interesting offset of the 26Al emission source from its likely sources and appears rather extended. This suggests that radioactivity is displaced from its sources into the Eridanus cavity. If true this opens unique possibilities to study the ISM near massive stars and the interaction of massive stars with their surroundings in a new way: Due to the proximity and location at the edge of a large cavity we can compare locations of massive stars to the morphology of the ISM and the emission pattern of 26Al radioactivity in order to constrain 26Al ejection in mass and velocity from massive stars. We aim to confirm and clarify the intensity and location of this nearby 26Al source with INTEGRAL. Furthermore with these observations we can check for annihilation radiation and for the intensity of nuclear deexcitation gamma-rays in the MeV range both valuable diagnostics of the structure of superbubble interiors. It is important for INTEGRAL to assess the scientific potential of Orion region observations now this will give us the option to eventually obtain unique measurements of ISM dynamics and massive stars as its driving engines within INTEGRALs lifetime there is hardly a more suitable and closeby target region. [truncated! Please see actual data for full text]