Description
The Palomar 60-inch (1.5 metre) telescope conducted an automated optical GRB follow-up programme from 2005 to 2017. It was configured to respond automatically, in less than three minutes, to well-localised GRB alerts, and it was one of the largest optical telescopes with such a programme at the time. The rapid response to the alerts resulted in 88 follow-up observations within one hour of Swift trigger, with a 63% afterglow detection rate and a typical depth of a single exposure of r ~ 20 mag. The resulting sample of 55 afterglows makes the dataset a valuable tool for investigating the entirety of the GRB population. This talk presents the first results from the full 13-year long sample, including an investigation of the decay and spectral properties of P60 afterglows, as well as their luminosity distribution and time-dependent optical luminosity function. The full dataset, combined with observations from other facilities and compared with numerical models of afterglows, will be used to characterize GRB jet properties, such as energy ranges or opening angles, as well as the true rates of relativistic jets. The results provide insight into the population of low-luminosity relativistic transients and their connection to X-ray transients, bridging the gap to a parameter space now explored by Einstein Probe and SVOM.
