Pulsating Stars and the Distance Scale - II

Abstract

The current Cepheid zero-point is equivalent to an LMC distance modulus of 18.57 ± 0.10. The zero-point from corrected Baade-Wesselink data is probably not significantly different from this. A reexamination of the Baade-Wesselink data for RR Lyrae variables leads to an LMC modulus of 18.51, an age difference between β- and α-group galactic globular clusters of +1.46±0.70 Gyr, and an Mv - [Fe/H] slope in agreement with theory. Other questions discussed include; Avoiding bias in using the Cepheid PL relation; Metallicity spread amongst Cepheids; Cepheids and Ho.