******************************************************
   PR # 42012
   We propose to obtain ASCA spectra of the active solar-type dwarf Chi
   Ori to probe the mechanisms which give rise to hot and cool plasma in
   late-type main-sequence coronae. These observations are part of a
   program to study the dependence of coronal temperature on
   convection-zone depth. Despite Einstein, ROSAT, and EUVE observations
   of Chi Ori, its true emission measure distribution, particularly
   above 10 MK, is still poorly known. SIS and GIS spectra will
   constrain the temperature of the very hottest coronal plasma. When
   combined with EUVE spectra, the ASCA spectra will further constrain
   the emission-measure distributions. The dependence of the
   emission-measures on convection-zone depth will allow us to test the
   hypothesis that increased dynamo action leads to higher coronal
   temperatures.
  ******************************************************