[en] The authors correlate Einstein observations of the X-ray flux of quiescent dMe stars with the time-averaged energy emitted by flares in the Johnson-U band, showing that the X-ray energy emitted by the coronae of these stars is about an order of magnitude greater than the U-band flare energy. From the estimate of the ratio of the total radiation emitted to the U-band flux, it is possible that, if a similar amount of energy were dissipated in the stellar atmosphere, then the observed flare events could heat the coronae of these stars. (author)