[en] An observational test for the hypothesis of the binary nature of the peculiar type 1 supernovae suggesting red supergiant as a companion is proposed. The interaction of the supernova envelope with the comparison is shown to result in the ejection of the (0.3-1) M* (M* - solar mass) of the red supergiant matter with the expansion velocities < or approx. 1000 km/s. This ejected matter turns out to be inside the supernova envelope, occupying the central part < or approx. 20% of the radius. In the case of close binaries the luminosity of ejection at the late stage (∼ 300^d) could be of the order of (or exceed) the luminosity of the supernova itself. The spectrum of the ejection radiation is produced by the hydrogen continuum radiation. The narrow ( < or approx. 1000 km/s) H_α emission line with the luminosity far less as compared to that of the continuum should be also present