4 Pulsar Timing 

It became clear soon after their discovery that pulsars are excellent celestial clocks. In the original discovery paper [97], the period of the first pulsar to be discovered, PSR B1919+21, was found to be stable to one part in over a time-scale of a few months. Following the discovery of the millisecond pulsar B1937+21 in 1982 [17] it was demonstrated that its period could be measured to one part in or better [65]. This unrivaled stability leads to a host of applications including time keeping, probes of relativistic gravity and natural gravitational wave detectors.

• 4.1 Observing basics
• 4.2 The timing model
• 4.3 Timing stability
• 4.4 Binary pulsars and Kepler's laws
• 4.5 Post-Keplerian parameters
• 4.6 Geodetic precession
• 4.7 Going further

Binary and Millisecond Pulsars at the New Millennium Duncan R. Lorimer http://www.livingreviews.org/lrr-2001-5 © Max-Planck-Gesellschaft. ISSN 1433-8351 Problems/Comments to livrev@aei-potsdam.mpg.de