******************************************************
   PR # 12152
      We propose to observe the rapidly variable Seyfert 1 galaxy Mkn766
    simultaneously with ASCA and ROSAT, in order to study its broad band
    spectral and temporal behavior. Our time constrained ROSAT AO4 observ
    ation has already been approved.Observation of correlated variability
    between the soft component and absorption -- best measured with ROSAT
    -- and the continuum -- best measured with ASCA, will allow us to
    place strong model independent constraints on the geometry.  Further-
    more, the broad band coverage and good spectral resolution will allow
    us to perform detailed spectral fitting during events of variability,
    thus allowing further constraints on the models of the emission
    mechanism.

 ******************************************************