The Host Galaxies of Long Duration GRBs . ... Astrophysicists still aren't sure, but the longest duration gamma-ray bursts (GRBs) seem to involve very massive stars. ... These images, shown above , indicate that long duration GRBs typically appear to come from galaxies and regions of galaxies with bright regions rich with star formation and bright, massive stars . Long GRBs are therefore different than many types of supernovas , which occur more uniformly distributed in their host galaxies. ...