A glitch in the Crab Pulsar

• Published in: Monthly notices of the Royal Astronomical Society Vol. 229; no. 2; pp. 223 - 226
• Main Authors: Lyne, A. G., Pritchard, R. S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford University Press 01-11-1987
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/229.2.223

Until last year the pulsar in the Crab Nebula, PSR 0531+21, had suffered two major glitches, or jumps in rotation rate, since it was discovered in 1968. The first, in 1969, involved a fractional change in period of $\Delta P/P\approx10^{-8}$ while the second, in 1975, was much larger with $\Delta P/P\approx4\times 10^{-8}$. Observations were not made until several days after each event. This paper reports a third glitch, in 1986 August, detected at Jodrell Bank apparently within 1 hr of the event. This is the first occasion on which the recovery from a glitch in the Crab Pulsar has been observed in detail. The recovery in rotation rate is close to a simple exponential and can be understood in terms of a two-component model of the neutron star.