Scanner observations of the classical Cepheids RT Aur and T Vul

Abstract

The effective temperatures of the classical Cepheids RT Aur and T Vul have been determined by a comparison of their spectral scans with appropriate model atmospheres. The radii of the stars have been determined through the Wesselink method. Using these temperatures and the Wesselink radii, the luminosities of the stars have been determined. These radii estimates, including the radii of SU Cas (Joshi & Rautels 1980) and ζ Gem (unpublished) fit better in the theoretical period-radius relationship given by Cogan (1978), as compared to earlier determinations of Wesseling radii. The pulsation masses and evolutionary masses of the stars have been calculated. The pulsation to evolutionary mass ration is derived to be 0.85.