Interplanetary Scintillation of Small Diameter Radio Sources

Previous observations 4 of flares on EV Lacertae in yellow and blue light have ~hown that 1/(yellow)/J/(blue) = 0·23 at maximum light, and this has been used as tho correction factor. The estimates of tho optical and radio energies in the flares on the three stars are given in Table 2. The optical energies havo been obtained by using the black-body equations to calculate the increased radiation appropriate to the observed brightness increase in the star over a 1,000 A.u. band-width at 5,400 A.u. The apparent photovisual magnitudes mpv quoted in Table 2 are for the combined light of both components of the binary in the case of UV Ceti, and it is assumed that the stars radiate uniformly into TC steradians. The energies are based on a stellar radius of 0·080 for UV Ceti and for radii typical of dM5e stars in the case of EV L acortao and Ross 882.