Another glitch in the Crab pulsar (PSR B0531+21) following the July 2025 event
ATel #17331; Benjamin Shaw (University of Manchester), Danai Antonopoulou (UoM), Michael J. Keith (UoM), Andrew G. Lyne (UoM), Mitchell B. Mickaliger (UoM), Benjamin W. Stappers (UoM), Patrick Weltevrede (UoM)
on 13 Aug 2025; 12:22 UT
Credential Certification: Benjamin Shaw (benjamin.shaw@manchester.ac.uk)
Subjects: Radio, Neutron Star, Pulsar
We report the detection of a glitch in the Crab pulsar (PSR B0531+21), just 20 days after the previous event reported in ATel #17298. The new event occurred on 2025 August 6, representing the shortest inter-glitch interval ever observed in this source. The Crab pulsar is monitored daily as part of the Jodrell Bank Pulsar Timing Programme. Observations are conducted using the 42-ft telescope at 610 MHz (4 MHz bandwidth) for approximately 11 hours per day, with shorter observations using the Lovell Telescope at 1532 MHz (384 MHz bandwidth). Preliminary timing analysis indicates a fractional increase in spin frequency of dF0/F0 = 4.53(17)E-09 and a fractional increase in the spin-down rate of dF1/F1 = 0.44(7)E-03 (1-sigma uncertainties). The glitch epoch is currently estimated as MJD 60893.9(7). No post-glitch recovery has yet been identified, but daily monitoring is ongoing.
