High Quality Content by WIKIPEDIA articles! In astrophysics, an extreme mass ratio inspiral (EMRI) is the orbit of a light object around a much heavier (by a factor 10,000 or more) object, that gradually decays due the emission of gravitational waves. Such systems are likely to be found in the centers of galaxies, where stellar mass compact objects, such as stellar black holes and neutron stars, may be found orbiting a supermassive black hole. In the case of a black hole in orbit around another black hole this is an extreme mass ratio binary black hole.