Color–magnitude diagram constructed based on HST WFC3/IR data for the cluster field with the marked location of the discovered ultracompact system (red dot). Its position ≈0.25 mag blueward of the main-sequence turnoff shows that this is a hot object. The arrow represents the reddening vector in the direction of the variable object as determined from maps in Nataf et al. (2013) and Nataf (2015).