During the analysis of RR Lyrae stars discovered in the High cadence
Transient Survey (HiTS) taken with the Dark Energy Camera at the 4-m telescope
at Cerro Tololo Inter-American Observatory, we found a group of three very
distant, fundamental mode pulsator RR Lyrae (type ab). The location of these
stars agrees with them belonging to the Leo V ultra-faint satellite galaxy, for
which no variable stars have been reported to date. The heliocentric distance
derived for Leo V based on these stars is 173 +/- 5 kpc. The pulsational
properties (amplitudes and periods) of these stars locate them within the locus
of the Oosterhoff II group, similar to most other ultra-faint galaxies with
known RR Lyrae stars. This serendipitous discovery shows that distant RR Lyrae
stars may be used to search for unknown faint stellar systems in the outskirts
of the Milky Way.Comment: Accepted in ApJ Letter
