2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199931We consider here the decay of unstable particles in geodesic circular motion around compact objects. For the neutron, in particular, strong and weak decay are calculated by means of a semiclassical approach. Noticeable effects are expected to occur as one approaches the photonic circular orbit of realistic black-holes. We argue that, in such a limit,the quasi-thermal spectrum inherent to extremely relativistic observers in circular motion plays a role similar to the Unruh radiation for uniformly accelerated observers.6 pages, 4 figures. Final version to appear in PRDGeneral Relativity and Quantum Cosmologytext