Constraints on Type Ib/c Supernovae and Gamma‐Ray Burst Progenitors

Although there is strong support for the collapsar engine as the power source of long‐duration gamma‐ray bursts (GRBs), we still do not definitively know the progenitor of these explosions. Here we review the current set of progenitor scenarios for long‐duration GRBs and the observational constraints on these scenarios. Examining these models, we find that single stars cannot be the only progenitor for long‐duration GRBs. Several binary progenitors can match the solid observational constraints and also have the potential to match the trends that we are currently seeing in the observations. Type Ib/c supernovae are also likely to be produced primarily in binaries; we discuss the relationship between the progenitors of these explosions and those of the long‐duration GRBs.