COLOR INDEXES OF DOUBLE-MODE CEPHEIDS

For the first time, we have constructed separate curves for the color indices of both oscillations in all double-mode Cepheids. An analysis of approximately 4600 photoelectric UBVRI observations by various auth ors showed that the shape of each curve changes with a period equal to the period of the other oscillation. Data on the changes in the ampli tudes of the color indices confirm the earlier conclusion that the gro up of double-mode Cepheids is divided into two subgroups.