The collective motion of stars in the cores of galaxies reveals the presence of supermassive black holes, generally millions to billions of times more massive than the Sun. Gravitational waves can deliver a kick to orbiting stars when two supermassive black holes collide during galaxy mergers, reorganizing stellar orbits into a lopsided, eccentric disk around the recoiling black hole. This is precisely what is observed in the nucleus of our nearest major galaxy neighbor, Andromeda, which suggests that Andromeda might harbor a recoiled black hole that has returned to the galaxy’s nucleus through dynamical friction. A 3-year research program led by investigators at the University of Colorado at Boulder will rigorously test this hypothesis. The team will compare computer simulations with observations of the Andromeda nucleus to determine merger event rates and characteristics of high-energy transients following a merger. The investigators will implement a series of Sensory-Friendly planetarium experiences at the University of Colorado Boulder. Guidelines and activities will be developed in collaboration with the Autism Society of Boulder County and the Speech, Language, and Hearing Clinic at the University of Colorado Boulder. These events, accessible to all, would broaden theater participation to neurodiverse children, opening the full dome experience and wonders of the night sky to all families. The investigators will use theoretically motivated initial conditions for stell