All current gamma-ray observatories have tried to detect emisson from gamma-ray bursts (GRBs) over the last two decades. After many un-successfull attempts, the last years have seen various breakthroughs.
On September 20, 2018, H.E.S.S. performed follow-up observations of a burst detected by Swift, Fermi and others. This observation would turn out to be the first successfull detection of VHE radiation from a GRB. Details are discussed in this blog entry: GRB 180720B
After GRB 180720B provided the first proof for the existence of the long-sought VHE radiation in the GRB afterglow, the H.E.S.S. observations that I led on GRB 190829A constituted other surprises: the emission is also present in low-luminosity bursts, it can last for several days and the MWL spectrum is hard to understand within our current models. More details are available in this blog post: GRB 190829A
Radiation from the brightest GRBs in the history of mankind was recorded by pratically all X-ray detectors. Unfortunately, due to bright moon-light, we had to wait two long days before starting an observation campaign with H.E.S.S. The obtained data did not show any signs of VHE photons from this monster burst. Still, the obtained limits on the gamma-ray flux provide guidance for the theoretical understanding of this special event. See this blog post for details: GRB 221009A