| Abstract | A double-mode period-IR luminosity relation for pulsating red supergiants (SRC-type variables) has been found in the Galaxy: MK(1) = -10.10 - 3.44 (lg (P)-2.7) and MK(2) = -9.56 - 3.44 (lg (P)-2.7). Distance moduli of LMC (DMLMC = 18.28±0.09) and of M33 (DMM33 = 24.24±0.09) have been estimated. The estimates being based on the adopted distance modulus of 11.4 for the Per OB1 stellar association. The ratio of the first overtone pulsation period to that of the main tone has been found to be the same both in the Galaxy and in M33, its value being P1/P0 = 0.70±0.04. |
