Related papers: Cepheid Mass-loss and the Pulsation -- Evolutionar…
We found the first direct evidence that the Cepheid class namesake, delta Cephei, is currently losing mass. These observations are based on data obtained with the Spitzer Space Telescope in the infrared, and with the Very Large Array in the…
Measurements of rates of period change of Classical Cepheids probe stellar physics and evolution. Additionally, better understanding of Cepheid structure and evolution provides greater insight into their use as standard candles and tools…
Helium-burning stars, in particular Cepheids, are especially difficult to model, as the choice of free parameters can greatly impact the shape of the blue loops - the part of the evolutionary track at which instability strip is crossed.…
Classical Cepheids are powerful probes of both stellar evolution and near-field cosmology thanks to their high luminosities, pulsations, and that they follow the Leavitt (Period-Luminosity) Law. However, there still exist a number of…
We recently showed that rotation significantly affects most observable Cepheid quantities, and that rotation, in combination with the evolutionary status of the star, can resolve the long-standing Cepheid mass discrepancy problem. We…
Measurements of secular period change probe real-time stellar evolution of classical Cepheids making these measurements powerful constraints for stellar evolution models, especially when coupled with interferometric measurements. In this…
We present the results of a search for HI 21-cm line emission from the circumstellar environments of four Galactic Cepheids (RS Pup, X Cyg, $\zeta$ Gem, and T Mon) based on observations with the Karl G. Jansky Very Large Array. The…
A deep and detailed examination of 29 classical Cepheids with the Spitzer Space Telescope has revealed three stars with strong nearby extended emission detected in multiple bands which appears to be physically associated with the stars. RS…
We utilize nonlinear pulsation models to reproduce the observed light and color curves for two samples of bump Cepheid variables, 19 from the Large Magellanic Cloud and 9 from the Small Magellanic Cloud. This analysis determines the…
We present a new Bayesian approach to constrain the intrinsic parameters (stellar mass, age) of the eclipsing binary system CEP0227 in the LMC. We computed evolutionary models covering a broad range in chemical compositions and in stellar…
The recent discovery and analysis of a classical Cepheid in the well detached, double-lined, eclipsing binary OGLE-LMC-CEP0227, has provided the first determination of the dynamical mass of a classical Cepheid variable to an unprecedented…
Cepheid masses are particularly necessary to help solving the mass discrepancy, while independent distance determinations provide crucial test of the period-luminosity relation and Gaia parallaxes. We used CHARA/MIRC to measure the…
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 1.3-2.2 Mo and various…
We briefly review the main problems related to the computation of the evolution of intermediate-mass stars: the treatment of turbulent convection and the occurrence of blue loops during the core He-burning phase. It is shown that, in order…
Recently published Spitzer observations of the classical Cepheid archetype delta Cephei revealed an extended dusty nebula surrounding this star and its hot companion. The infrared emission resembles a bow shock aligned with the direction of…
We present a differential study of 500 Magellanic Cepheids with 3 million measurements obtained as a by-product of the EROS microlensing survey. The data-set is unbiased and provides an excellent basis for a differential analysis between…
The evolution of massive stars is the basis of several astrophysical investigations, from predicting gravitational-wave event rates to studying star-formation and stellar populations in clusters. However, uncertainties in massive star…
Polaris the Cepheid has been observed for centuries, presenting surprises and changing our view of Cepheids and stellar astrophysics, in general. Specifically, understanding Polaris helps anchor the Cepheid Leavitt law, but the distance…
Pulsating stars, such as Cepheids and RR Lyrae, offer us a window to measure and study changes due to stellar evolution. In this work, we study the former by calculating a set of evolutionary tracks of stars with an initial mass of 4 to 7…
The study is devoted to radial pulsations in Population I Cepheids with masses from 5.4 to 6 Msun. Solution of the equations of radiation hydrodynamics and turbulent convection for nonlinear stellar pulsations was obtained with initial…