Finding Variable Stars in Newly Discovered Ultra-Faint Dwarf Galaxies

The pristine ultra-faint dwarf (UFD) galaxies are a few order of magnitude smaller than typical dwarf galaxies. Precise distance measurements, such as using RR Lyrae variable stars in them, can be used to determine if the UFD are dark matter dominated or not. Using observations taken from the Lulin One-meter Telescopes (LOT) and public data, Professor Chow-Choong Ngeow from the Graduate Institute of Astronomy, National Central University, searched for RR Lyrae in three recently discovered UFD – Virgo III, Aquarius III and Sextans II. Both Virgo III and Aquarius III were found to have 3 and 1 RR Lyrae, respectively, but none was found in Sextans II. Such results and experience will be valuable for those newly discovered UFD from the Rubin Observatory Legacy Survey of Space and Time (LSST).