Program: GS-2018B-FT-205

Short gamma-ray bursts (SGRBs) are among the most luminous transients in the Universe, and likely originate from the mergers of two neutron stars, or a neutron star and a black hole. In late July, the Swift SGRB 180727A was detected and localized via the detection of an X-ray afterglow. We initiated a rapid, deep optical search with Magellan, uncovering a faint optical source near the position of the X-ray afterglow. Here, we propose for 1 hr of Gemini-South/GMOS imaging to obtain a deep template image to determine whether the source was a very faint afterglow, or is persistent emission from a low-luminosity or high-redshift host galaxy. In either scenario, the event would be superlative in the SGRB population. Any awarded Gemini time will complement our existing Magellan and Chandra data for a comprehensive, multi-wavelength study. Since compact object mergers are now being discovered in the local Universe with Advanced LIGO/Virgo, SGRBs offer a complementary way to make progress in merger studies.