A comparison of coronal X-ray emission observed with the Einstein andEXOSAT observatories.

The present Einstein and Exosat observatories' star coronal X-ray emission data are subjected to a spectral analysis which employs the Raymond and Smith (1977) and Landini and Fossi (1984) computer codes to calculate X-ray emission from optically thin plasmas that are in collisional equilibrium. It is found that the derived coronal parameters depend only loosely on the details of the calculated theoretical X-ray spectrum, although the spectra nevertheless differ in their prediction of X-ray fluxes in various lines. It is demonstrated that the Einstein spectra and Exosat filter ratios can be naturally and simultaneously explained by assuming an underlying, continuous distribution of emission measure with temperature, as in the case of the solar corona.