As another possible use of the new equipment, we began an H-alpha and Ca K versus continuum survey of selected nearby stars in order to investigate their flare activity. As with the sun, one would expect active regions to pass from absorption to emission in strong lines during flares, making this a porentially sensitive differential method not dependent on total changes of brightness (which with flares may be very small in amplitude and diffi¬cult to pick out from the other fluctuations present from instrumental and atmospheric causes). Even with such relatively bright stars as the sun, a class 3+ flare should produce a change of greater than 0.l％ in the integrator-H-alpha light from the entire disk, an amount theoretically detectable by our equipment although below the practical working limit for individual observations set by photocell drift and by seeing and guiding variations shift¬ing slightly the focal spot to microscopically different regions of the photocathode having nevertheless significantly different sensitivity.
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