Physical parameters and pulsational mode of short-period small-amplitude Cepheids

Nine galactic short-period (P < 8 days) small-amplitude [(ΔV < 0.3)mag] Cepheids, have been the subject of a study to determine their physical parameters and pulsational properties. UBVRI photometry and radial velocities were obtained in the same observing seasons. The wings of Hα were used to determine effective temperatures. Empirical radii, luminosities and masses were determined. The short-period stars lie inside and seem to be on the red side of the observational Cepheid instability strip. It was found that these stars are likely pulsating in the radial fundamental mode except HR 8084 (DT Cyg) which is suspected to be a first overtone pulsator. (author)