The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. XV. Long-Period Variables in the Galactic Bulge

TL;DR

This paper presents a comprehensive catalog of over 232,000 long-period variable stars in the Galactic bulge from the OGLE-III survey, including detailed observational data and analysis of their properties.

Contribution

It provides the largest catalog of LPVs in the Galactic bulge with detailed photometry, classifications, and comparative analysis with Magellanic Clouds data.

Findings

Majority of bulge red giants are oxygen-rich.

Mira variables form a distinct group in the period-amplitude diagram.

Fewer long-secondary period stars are observed toward the Galactic center.

Abstract

The fifteenth part of the OGLE-III Catalog of Variable Stars (OIII-CVS) contains 232,406 long-period variables (LPVs) detected in the OGLE-II and OGLE-III fields toward the Galactic bulge. The sample consists of 6528 Mira stars, 33,235 semiregular variables and 192,643 OGLE small amplitude red giants. The catalog data and data resources that are being published include observational parameters of stars, finding charts, and time-series I- and V-band photometry obtained between 1997 and 2009. We discuss statistical features of the sample and compare it with collections of LPVs in the Magellanic Clouds. The vast majority of red giant stars in the Galactic bulge have an oxygen-rich chemistry. Mira variables form a separate group in the period-amplitude diagram, which was not noticed for oxygen-rich Miras in the Magellanic Clouds. We find a clear deficit of long-secondary period stars toward the Galactic center compared to the sample of Magellanic Clouds' LPVs.