A Simple Way to Estimate the Soft X-ray Class of Far-Side . Solar Flares Observed with STEREO/EUVI . ... Figure 1. The STEREO/EUVI 195 °A B-streaks typical of C-, M-, and X-class flares. Table 1: A list of flares registered both with GOES and STEREO/EUVI . ... Impulsive GOES M-class flares and their thin, single, long B-streaks. ... STEREO/EUVI B-streak and the peak of the SXR flux measured by GOES. ... A list of major far-side flares detected from B-streaks in STEREO/EUVI 195 °A images. ...