The Coronae of AD Leo and EV Lac

e second one, responsible for the high energy emission, is composed at least of tens of quite elongated loops, covering a very small fraction of stellar surface. 1. Introduction Einstein IPC X-ray spectra of solar-type stars, observed with sufficient photon statistics, usually require two emission components from an optically thin plasma to be adeguatelly modeled (cf. Vaiana 1983, Schmitt et al. 1990). In the case of dMe stars the fits usually result in one component at few million degrees, and a second one at few tens million degrees. While the need of two thermal components does not necessarily imply the presence of two distinct emitting "regions" at different temperatures in the stellar coronae, it certainly reflect the presence of a (complex) thermal structure in stellar coronae. This description has been confirmed and extended by the analysis of spectra gathered with the Position Sensitive Proportional Counter (PSPC) on board ROSAT. The recent analysis o