A very large glitch in the radio pulsar PSR B0740-28

We have detected a large glitch event in the timing data of the radio pulsar PSR B0740-28 (J0742-2822), which we monitor routinely as part of the pulsar timing programme at the Jodrell Bank Observatory. PSR B0740-28 has a spin-frequency of 6 Hz and a characteristic (spin-down) age of 160 kyr. We monitor PSR B0740-28 for 1 hour per day with the 42-ft telescope and approximately weekly with the Lovell telescope. The glitch occurred on Saturday the 17th of September 2022, and our preliminary analysis indicates a fractional rotational spin-up of dF0/F0 = (4304.2+/-1.0)E-9 (1 sigma), which makes it the largest of the 9 glitches reported in this pulsar. There is no current indication of a significant change in the spin-down rate. We currently constrain the glitch epoch to be MJD 59839.4+/-0.5. Follow-up observations of this pulsar are encouraged to help refine the glitch characteristics and to identify any radiative effects seen at other wavelengths.