Discovery and confirmation of the shortest gamma ray burst from a collapsar

Understand

Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the universe.

• The duration and hardness distribution of GRBs has two clusters, now understood to reflect (at least) two different progenitors.
• Short-hard GRBs (SGRBs; T90 <2 s) arise from compact binary mergers, while long-soft GRBs (LGRBs; T90 >2 s) have been attributed to the collapse of peculiar massive stars (collapsars).
• The discovery of SN 1998bw/GRB 980425 marked the first association of a LGRB with a collapsar and AT 2017gfo/GRB 170817A/GW170817 marked the first association of a SGRB with a binary neutron star merger, producing also gravitational wave (GW).