Related papers: Period-Luminosity Relation for Type II Cepheids
We identified a sample of 88 bona fide Population II Cepheids (henceforth referred to as Cepheids) and 44 candidates in Galactic globular clusters (GCs). Seventy-eight of the Cepheids in the sample align within $2\,\sigma$ of the…
Classical Cepheids are well-known and widely used distance indicators. As distance and extinction are usually degenerate, it is important to develop suitable methods to robustly anchor the distance scale. Here, we introduce a near-infrared…
There is strong evidence that the period-luminosity (PL) relation for the Large Magellanic Cloud (LMC) Cepheids shows a break at a period around 10 days. Since the LMC PL relation is extensively used in distance scale studies, the…
Based on new observations and improved modeling techniques, we have reanalyzed seven Cepheids in the Large Magellanic Cloud. Improved physical parameters have been determined for the exotic system OGLE LMC-CEP-1718 composed of two…
In spite of the relevance of Classical Cepheids as primary distance indicators, a general consensus on the dependence of the Period-Luminosity (PL) relation on the Cepheid chemical composition has not been achieved yet. From the theoretical…
The light curves of Cepheids and other variable stars in Field A of IC 1613, obtained with a CCD and no filter ($Wh$ photometry), have been analyzed. It is possible to separate first overtone from fundamental mode population I Cepheids…
Uncertainty in the metal abundance dependence of the Cepheid variable period- luminosity (PL) relation remains one of the outstanding sources of systematic error in the extragalactic distance scale and Hubble constant. To test for such a…
A subset of Post-AGB (PAGB) objects are the highly luminous RV Tauri variables that show similarities to Type-II Cepheids. By using a sample of known RV Tauri stars from the Magellanic Clouds we are able to determine period luminosity…
Classical Cepheid variable stars have been important indicators of extragalactic distance and Galactic evolution for over a century. The Spitzer Space Telescope has opened the possibility of extending the study of Cepheids into the mid- and…
Recent space-borne and ground-based observations provide photometric measurements as time series. The effect of interstellar dust extinction in the near-infrared range is only 10% of that measured in the V band. However, the sensitivity of…
Classical Cepheids (DCEPs) are the most important primary indicators for the extragalactic distance scale. Establishing the dependence on metallicity of their period--luminosity and period--Wesenheit (PL/PW) relations has deep consequences…
We present the mid-infrared (mid-IR) period$-$luminosity relations (PLRs) using over 1000 Mira variables in the Large Magellanic Cloud (LMC), for the four Wide-Field Infrared Survey Explorer (WISE) and the four Spitzer bands. These PLRs…
We examine the properties of 17 long period (80-180 days) and very luminous (median absolute magnitude of M_I= -7.93 and M_V= -7.03) Cepheids to see if they can serve as an useful distance indicator. We find that these Ultra Long Period…
Recent evidence has emerged that the Cepheid PL relation in the LMC is nonlinear in the sense that the existing data are more consistent with two lines of differing slope with a break at a period of 10 days. We review the statistical…
The eighth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains type II Cepheids in the Small Magellanic Cloud (SMC). The sample consists of 43 objects, including 17 BL Her, 17 W Vir and 9 RV Tau stars (first examples ever…
We have analysed 10 high resolution spectra of Type II Cepheids with periods less than 3 days. We find that they clearly separate into two groups: those with near or slightly below solar metallicities, and those with [Fe/H] between --1.5…
The VISTA Magellanic Cloud (VMC, PI M.R. Cioni) survey is collecting deep Ks-band time-series photometry of the pulsating variable stars hosted by the system formed by the two Magellanic Clouds (MCs) and the "bridge" connecting them. In…
We present the comparison between theoretical and empirical PL relations in V and I bands for the Large Magellanic Cloud. We found that, within the current intrinsic dispersions, theoretical predictions are in remarkable agreement with…
This is the second of two papers exploring the effects of metallicity on the multi-wavelength properties of Cepheids in terms of their multi-wavelength period-luminosity (PL) relations, impacting their use as extragalactic distance…
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…