Related papers: Empirical instability strip for classical Cepheids…
Despite observational evidences, InfraRed (IR) excess of classical Cepheids are seldom studied and poorly understood, but probably induces systematics on the Period-Luminosity (PL) relation used in the calibration of the extragalactic…
The Galactic Cepheid period histogram has a strong dip between 8 and 10 days that has defied an explanation based on evolutionary and linear pulsation studies. We show here that this deficiency is caused by the instability of the nonlinear…
Observations of Cepheids in the Large Magellanic Cloud, made over the last several decades, allow us to search for evolutionary period changes. None of the Cepheid from our sample of 378 stars stopped pulsating. Also none of them showed a…
We have performed a cross-identification between OGLE-II data and single-epoch SIRIUS JHK survey data in the LMC and SMC. After eliminating obvious spurious variables, we determined the pulsation periods for 9,681 and 2,927 variables in the…
We present a detailed analysis of the light curves and pulsation properties of First Overtone (FO) Cepheids in the Magellanic Clouds (MCs) obtained using observations and predictions from stellar pulsation models. Multiwavelength…
We present an improved determination of the Hubble constant (H0) from Hubble Space Telescope (HST) observations of 70 long-period Cepheids in the Large Magellanic Cloud. These were obtained with the same WFC3 photometric system used to…
We present a study of a recently discovered stellar overdensity near the northern edge of the Small Magellanic Cloud (SMCNOD). We exploited variable stars from the fourth release of the Optical Gravitational Lensing Experiment (OGLE). We…
We aim to investigate the IR excess of 45 MW Cepheids combining different observables to constrain the presence of CSE. We used the SPIPS algorithm, a robust implementation of the parallax-of-pulsation method that combines photometry,…
(Abridged) I cross-correlate the OGLE database of Cepheids in the Large and Small Magellanic Clouds (MCs) with the second incremental release of the 2MASS JHK survey, and the DENIS IJK point source catalog towards the MCs. Of the 3384…
We present a new set of Cepheid, full amplitude, nonlinear, convective models which are pulsationally unstable in the second overtone (SO). Hydrodynamical models were constructed by adopting a chemical composition typical for Cepheids in…
An analysis of the observed characteristics of the Galactic Cepheid variables is carried out in the framework of their period-luminosity relation being used as a standard candle for distance measurement. The variation of the observed number…
We present a detailed analysis of Magellanic Bridge Cepheid sample constructed using the OGLE Collection of Variable Stars. Our updated Bridge sample contains 10 classical and 13 anomalous Cepheids. We calculate their individual distances…
The nature of type II Cepheids and anomalous Cepheids is still not well known and their evolutionary channels leave many unanswered questions. We use complete collection of classical pulsating stars in the Magellanic Clouds discovered by…
We present candidates for non-pulsating stars lying in the classical Cepheid instability strip based on OGLE photometric maps combined with Str\"omgren photometry obtained with the 4.1-m SOAR telescope, and Gaia DR2 data in four fields in…
Classical Cepheids can be used as age indicators due to well-established period-age and period-age-color relations. \citet{Desomma2021} refined these relations by including a metallicity term and different Mass-Luminosity assumptions. In…
We undertake a new test of the metallicity sensitivity of the Leavitt Law for Classical Cepheids. We derive an empirical calibration of the apparent luminosities of Cepheids as measured from the optical through the mid-infrared (0.45-8.0um)…
We employed the {\it VISTA near-infrared $YJK_\mathrm{s}$ survey of the Magellanic System} (VMC), to analyse the $Y,\,J,\,K_\mathrm{s}$ light curves of $\delta$ Cepheid stars (DCEPs) in the Large Magellanic Cloud (LMC). Our sample consists…
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.…
We present here a nearly complete census of classical Cepheids in the Magellanic System. The sample extends the set of Cepheids published in the past by the Optical Gravitational Lensing Experiment (OGLE) to the outer regions of the Large…
A framework is outlined to assess Cepheids as potential cluster members from readily available photometric observations. A relationship is derived to estimate colour excess and distance for individual Cepheids through a calibration…