A glitch in the Crab pulsar (PSR B0531+21)
ATel #17298; 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 21 Jul 2025; 17:23 UT
Credential Certification: Benjamin Shaw (benjamin.shaw@manchester.ac.uk)
Subjects: Radio, Pulsar, Magnetar
We report the detection of a small glitch event in the timing data of the Crab pulsar (PSR B0531+21), which we monitor as part of the Jodrell Bank Pulsar Timing Programme. The Crab pulsar is observed daily with the 42-ft telescope using a 4 MHz wide band centred on 610 MHz. Additional short observations are carried out with the Lovell telescope using a 384 MHz wide band centred on 1532 MHz. This glitch is the 31st such event observed in this pulsar and occurred on 2025 July 17; ~6 years after the previous glitch in 2019. Preliminary analysis indicates a fractional rotational spin-up of dF0/F0 = 2.33(9)E-09 and a fractional change to the spin-down rate of dF1/F1 = 0.43(4)E-03 (1 sigma uncertainties). We currently measure the glitch epoch to be MJD 60873.95(35). At present, we find no evidence of any post-glitch transient behaviour; however we continue our daily monitoring of the pulsar. Observations at other facilities are encouraged in order to confirm the glitch and refine the measured parameters.
