Over 38000 RR Lyrae Stars in the OGLE Galactic Bulge Fields

Understand

We present the most comprehensive picture ever obtained of the central parts of the Milky Way probed with RR Lyrae variable stars.

• This is a collection of 38257 RR Lyr stars detected over 182 square degrees monitored photometrically by the Optical Gravitational Lensing Experiment (OGLE) in the most central regions of the Galactic bulge.
• The sample consists of 16804 variables found and published by the OGLE collaboration in 2011 and 21453 RR Lyr stars newly detected in the photometric databases of the fourth phase of the OGLE survey (OGLE-IV).
• 93% of the OGLE-IV variables were previously unknown.