Related papers: On the Cepheid Metallicity Dichotomy

The theoretical period-luminosity relation for Cepheids was deduced from stellar evolution and pulsation computations. Questions concerning the metallicity dependence of the relation as well as the constancy of the pulsation `constant' Q in…

We submitted the available photometric V data of all the known galactic Double Mode Cepheids (DMCs) to a careful frequency analysis with the aim of detecting in each case the importance of the harmonics and of the cross coupling terms. For…

Using an updated and significantly augmented sample of Cepheid and TRGB distances to 28 nearby spiral and irregular galaxies, covering a wide range of metallicities, we have searched for evidence of a correlation of the zero-point of the…

We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of type Ia supernovae recently revealed by type Ia…

We use very deep spectra obtained with the Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope to derive physical conditions and chemical abundances of four H II regions of the Large Magellanic Cloud (LMC) and four H II…

The purpose of this preliminary work is to determine if Large Magellanic Cloud (LMC) Cepheids have stellar winds. If a Cepheid undergoes mass loss then at some distance from the star, a fraction of the gas becomes dust, which causes an…

Classical Cepheids (DCEPs) are crucial for calibrating the extragalactic distance ladder, ultimately enabling the determination of the Hubble constant through the PL and PW relations they exhibit. Hence it's vital to understand how the PL…

There is a serious discrepancy between the distance to the LMC derived from the Cepheid Period-Luminosity relation and that obtained by using the Galactic calibration for the luminosity of RR Lyrae stars. It is suggested that this problem…

The extragalactic distance scale builds on the Cepheid period-luminosity (PL) relation. In this paper, we want to carry out a strictly differential comparison of the absolute PL relations obeyed by classical Cepheids in the Milky Way (MW),…

We investigate the theoretical scenario concerning the large sample of variables recently discovered in the dwarf, metal-poor irregular galaxy Leo A, focusing the attention on the "Anomalous" Cepheid phenomenon and its correlation with RR…

In this paper we present multi-band period-luminosity (P-L) relations for fundamental mode Cepheids in the SMC. The optical VI-band mean magnitudes for these SMC Cepheids were taken from the third phase of the Optical Gravitational Lensing…

One of the outstanding problems in modern physics is the origin is of accelerated expansion of the universe. High-precision determinations of the Hubble parameter $\mbox{H}_0$ at different redshifts provide direct insight into the Universe…

We performed a new and accurate fit of light and radial velocity curves of the Large Magellanic Cloud (LMC) Cepheid --OGLE-LMC-CEP-0227-- belonging to a detached double-lined eclipsing binary system. We computed several sets of nonlinear,…

In this paper, we construct full amplitude non-linear hydrodynamical models of fundamental mode Galactic Cepheids and analyze the resulting theoretical period-colour and amplitude-colour relations at maximum, mean and minimum light. These…

We report the discovery of eleven beat Cepheids in the Small Magellanic Cloud, using data obtained by the EROS microlensing survey. Four stars are beating in the fundamental and first overtone mode (F/1OT), seven are beating in the first…

[Abridged] We calculate the structural evolution and nucleosynthesis of a grid of models covering the metallicity range: -6.5 < [Fe/H] < -3.0 (plus Z=0), and mass range: 0.85 < M < 3.0 Msun, amounting to 20 stars in total. In this paper,…

We derive basic stellar parameters (angular diameters, effective temperatures, metallicities) and interstellar reddening for all beta Cephei stars observed during the IUE satellite mission, including those belonging to three open clusters.…

Classical Cepheids are primary distance indicators and a crucial stepping stone to determining the present-day Hubble constant Ho to the precision and accuracy required to constrain apparent deviations from the LCDM Concordance Cosmological…

In this paper the synthetic period-luminosity (P-L) relations in Spitzer's IRAC bands, based on a series of theoretical pulsation models with varying metal and helium abundance, were investigated. Selected sets of these synthetic P-L…

We present a measurement of metallicity in the Galactic center Quintuplet Cluster made using quantitative spectral analysis of two Luminous Blue Variables (LBVs). The analysis employs line-blanketed NLTE wind/atmosphere models fit to…