New Short-Period Delta Scuti Stars in OGLE-IV Fields toward the Galactic Bulge

TL;DR

This paper reports the discovery and classification of 24 new short-period delta Scuti stars in the OGLE-IV Galactic bulge fields, expanding the catalog of such pulsators with detailed photometric and spectroscopic analysis.

Contribution

The study identifies and classifies 24 new short-period delta Scuti stars in the Galactic bulge, providing their photometric and spectroscopic properties for the first time.

Findings

All stars are main sequence A/F-type stars.

Stars exhibit low-amplitude, multi-periodic pulsations.

Periods range from 22 to 54 minutes.

Abstract

We report the classification of 24 puzzling short-period variable stars located in OGLE-IV Galactic bulge fields. The stars are low-amplitude (<0.05 mag) multi-periodic objects with dominant periods between 22 and 54 min whose type could not have been unambiguously established based on photometry only. A low-resolution spectroscopic follow-up has shown that all the objects are main sequence A/F-type stars. Thus, all the variables are delta Sct-type pulsators. We have added them to the OGLE-IV Collection of Variable Stars.