backFinal Results of Searches for BLAPs in the OGLE Inner Galactic Bulge Fields
Using the long-term OGLE-III and OGLE-IV observations collected between 2001 and 2024, we have carried out a systematic search for short-period variable stars in the inner regions of the Galactic bulge (pink area in the map below). By analyzing the I-band light curves of more than 400 million stars, we have identified 90 Blue Large-Amplitude Pulsators (BLAPs), nearly doubling the known sample to around 200 objects.
The newly discovered BLAPs display pulsation periods between roughly 5 and 76 minutes, with amplitudes typically ranging from 0.1 to 0.4 mag. Several of these objects exhibit exceptionally large period changes, on the order of 10⁻⁵ yr⁻¹, providing valuable clues about the evolutionary processes shaping this rare class of radial-mode pulsators. In a few cases, we also detected multiple pulsation frequencies, offering further insight into their internal structure.
Our comprehensive catalog includes detailed time-series photometry, light-curve morphology, amplitude and period analyses, and spatial distribution across the bulge. Completeness simulations show that our sample is nearly complete for stars brighter than I=18.5 mag.
Location of all known BLAPs in Galactic coordinates.
BLAPs in the period-amplitude diagram.
A color-magnitude diagram with the location of dereddened BLAPs observed toward the Galactic bulge. Colors code the pulsation period.
The underlying OGLE-IV photometry data are available to the astronomical community from the OGLE Internet Archive.
PLEASE cite the following paper when using the data or referring to these OGLE results:
Borowicz J. et al, 2025, arXiv:2510.20823
Any comments about the data and the form of their presentation are welcome as they can improve the future releases of OGLE analysis. Send your messages to this address.
back