45 Years of Rotation of the Crab Pulsar

Understand

The 30-Hz rotation rate of the Crab pulsar has been monitored at Jodrell Bank Observatory since 1984 and by other observatories before then.

• Since 1968, the rotation rate has decreased by about $0.5$\,Hz, interrupted only by sporadic and small spin up events (glitches).
• 24 of these events have been observed, including a significant concentration of 15 occurring over an interval of 11 years following MJD 50000.
• The monotonic decrease of the slowdown rate is partially reversed at glitches.