Mass ejection, compact objects, and electromagnetic transients

Abstract: Mass ejection is involved in the generation of many types of electromagnetic transient, often in the presence of at least one compact stellar object. A variety of processes can cause mass to become unbound from a gravitational field, including neutrino emission or absorption, magnetic stresses, angular momentum transport, or nuclear processes. In this talk I will discuss two astrophysical situations in which non-trivial mass ejection from the vicinity of a compact object should occur: the accretion disk formed in a neutron star merger, which contributes to the kilonova ejecta, and a failed supernova, in which non-negligible amounts of mass are expelled and interesting transients can result.