The OGLE-III Catalog of Variable Stars

XIV. Classical and Type II Cepheids in the Galactic Bulge

The fourteenth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains Cepheid variables detected in the OGLE-II and OGLE-III fields toward the Galactic bulge. The catalog is divided into two main categories: 32 classical Cepheids (21 single-mode fundamental-mode F, four first-overtone 1O, two double-mode F/1O, three double-mode 1O/2O and two triple-mode 1O/2O/3O pulsators) and 335 type II Cepheids (156 BL Her, 128 W Vir and 51 RV Tau stars). Six of the type II Cepheids likely belong to the Sagittarius Dwarf Spheroidal Galaxy. The catalog data include the time-series photometry collected in the course of the OGLE survey, observational parameters of the stars, finding charts, and cross-identifications with the General Catalogue of Variable Stars.

Light curves of classical and type II Cepheids in the Galactic bulge

We discuss some statistical properties of the sample and compare it with the OGLE catalogs of Cepheids in the Large and Small Magellanic Clouds. Multi-mode classical Cepheids in the Galactic bulge show systematically smaller period ratios than their counterparts in the Magellanic Clouds. BL Her in the Galactic bulge stars seem to be brighter than the linear extension of the period-luminosity relation defined by the longer-period type II Cepheids. We also show individual stars of particular interest, like two BL Her stars with period doubling.

Period-luminosity diagram for Cepheids and RR Lyrae stars in the Galactic bulge

For each object the multi-epoch V- and I-band photometry collected over 8 or 13 years of observations and finding charts are available to the astronomical community from the OGLE Internet archive (classical Cepheids, type II Cepheids).

PLEASE cite the following paper when using the data or referring to these OGLE results:
Soszyński et al. 2011, Acta Astronomica, 61, 285 (arXiv:1112.1406)

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.