A Four-Factor Framework for Gamma-Ray Burst Duration
A framework arguing that a gamma-ray burst's observed duration is shaped by four separable factors - progenitor, central engine, emitter, and geometry - rather than by progenitor type alone. The progenitor-defined duration applies only for accretion-powered engines; the scheme reconciles recent duration/progenitor mismatches (GRB 200826A, 211211A, 230307A) by invoking millisecond-magnetar engines, mini-jets, and a possible white-dwarf-neutron-star merger.
2501.00239
Gamma-ray burst (GRB) durations, measured by T90, form a bimodal distribution that splits bursts into short (T90 < 2 s) and long (> 2 s), historically mapped onto two progenitor classes: compact bina…