What “masses” for Cepheids?

Experimental Envelope Models for Cepheids

Period-Luminosity Relation for Type II Cepheids

We have estimated JHKs magnitudes corrected to mean intensity for LMC type II Cepheids found in the OGLE-III survey. Period-luminosity relations (PLRs) are derived in JHKs as well as in a reddening-free V I parameter. The BL Her stars (P < 4 d) and the W Vir stars (P = 4 to 20 d) are co-linear in these PLRs. The slopes of the infrared relations agree with those found previously for type II Ceph...

Cepheids: Pulsation, Evolution, Opacity

We describe modeling of the ''beat'' and "bump" Cepheids, using the new radiative opacities. Discrepancies between these models and the evolutionary tracks for stars of appropriate mass are discussed. Finally, we point out some of the difficulties involving the long-period Cepheid sample with periods greater than 20 days.

Updated pulsation models for anomalous Cepheids

A theoretical investigation of the pulsation behavior of so-named " anomalous " Cepheids is presented. The study is based on nonlinear convective pulsation models with Z=0.0001 and 0.0004, mass in the range 1.3-2.2M⊙ and various luminosity levels. Based on these computations, we derive period, bolometric light curves and the edges of the instability strip, showing that a variation of the metal ...

Nonlinear model pulsations for long-period Cepheids II. Magellanic Cloud Cepheids

Nonlinear, radiative models for long–period Cepheids in the Magellanic Clouds were constructed and the theoretical light and velocity curves were compared with observations. We assumed a metal content Z = 0.005, and two mass–luminosity M–L relations: one was obtained from stellar evolution calculation with convective overshooting models, and the other, which gives an even larger L for the same ...