The OGLE Collection of Variable Stars: Over 18 000 Rotating Variables toward the Galactic Bulge

TL;DR

This paper presents a comprehensive collection of over 18,000 rotating variable stars near the Galactic bulge, providing valuable long-term photometric data for studying stellar magnetic activity and rotation.

Contribution

The study introduces a large, publicly available dataset of rotating variables with detailed observational parameters, enhancing resources for stellar magnetic activity research.

Findings

Identification of 18,443 rotating variables with magnetic activity signatures

Provision of long-term photometric data spanning over two decades

Dataset includes rotation periods, brightness, and amplitude measurements

Abstract

Stellar rotation, a key factor influencing stellar structure and evolution, also drives magnetic activity, which is manifested as spots or flares on stellar surface. Here, we present a collection of 18 443 rotating variables located toward the Galactic bulge, identified in the photometric database of the Optical Gravitational Lensing Experiment (OGLE) project. These stars exhibit distinct magnetic activity, including starspots and flares. With this collection, we provide long-term, time-series photometry in Cousins I- and Johnson V-band obtained by OGLE since 1997, and basic observational parameters, i.e., equatorial coordinates, rotation periods, mean brightness, and brightness amplitudes in both bands. This is a unique dataset for studying stellar magnetic activity, including activity cycles.