4PiSky Authors: Gemma Anderson / Tim Staley / Rob Fender
AMI-LA Rapid Response Mode (ALARRM) observations of the nearby bright gamma-ray burst GRB 130427A allowed the 4 Pi Sky team to obtain one of the earliest radio detections of a GRB to date. As soon as this GRB had risen above the horizon the AMI-LA quickly slewed to its position detecting radio emission within 8 hours post-burst. Further follow-up AMI observations showed the radio flux to increase in brightness before rapidly declining one day later. Such a sudden decline in radio emission is very rare and has only been observed from a few GRBs.