The OGLE-III Catalog of Variable Stars

I. Classical Cepheids in the Large Magellanic Cloud

We present the first part of a new catalog of variable stars (OIII-CVS) compiled from the data collected in the course of the third phase of the Optical Gravitational Lensing Experiment (OGLE-III). In this paper we describe the catalog of 3361 classical Cepheids detected in the ~40 square degrees area in the Large Magellanic Cloud. The sample consists of 1848 fundamental-mode (F), 1228 first-overtone (1O), 14 second-overtone (2O), 61 double-mode F/1O, 203 double-mode 1O/2O, 2 double-mode 1O/3O, and 5 triple-mode classical Cepheids. This sample is supplemented by the list of 23 ultra-low amplitude variable stars which may be Cepheids entering or exiting instability strip.

LMC map

The catalog data include VI high-quality photometry collected since 2001, and for some of the stars supplemented by OGLE-II photometry obtained between 1997 and 2000. We provide basic parameters of the stars: coordinates, periods, mean magnitudes, amplitudes and parameters of the Fourier light curves decompositions. Our sample of Cepheids is cross-identified with previously published catalogs of these variables in the LMC. Individual objects of particular interest are discussed, including single-mode second-overtone Cepheids, multiperiodic pulsators with unusual period ratios or Cepheids in eclipsing binary systems.

PL diagram

We discuss the variations of the Fourier coefficients with periods and point out on the sharp feature for periods around 0.35 days of first-overtone Cepheids, which can be explained by the occurrence of 2:1 resonance between the first and fifth overtone. Similar behavior at P=3 days for 1O Cepheids and P=10 days for F Cepheids are also interpreted as an effect of resonances between two radial modes. We fit the period-luminosity relations to our sample of Cepheids and compare these functions with the previous determinations.

Light curves

The OGLE-III Catalog of Cepheids in the LMC is available from the OGLE Internet archive. See README file there for details.

PLEASE cite the following paper when using the data or referring to these OGLE results:
Soszyński et al., 2008, Acta Astron., 58, 163 (astro-ph/0808.2210)

Any comments about the data and the form of their presentation are welcome as they can improve the future releases of catalogs of variable stars detected by the OGLE collaboration. Send your messages to this address.