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The young pulsar PSR B1828−11 was discovered with the 76-m Lovell
Telescope at Jodrell Bank Observatory in the late 1980s. With a pulse
period is 405 ms, a dispersion measure of ~160 pc/cm^3, and a
characteristic age of 110 kyr, it appeared at first glance to be an
unremarkable object among the pulsar population. However, routine and
eventually more intensive follow-up with the Lovell Telescope showed
that it displays roughly periodic variations in its spin-down rate,
making it very unsual. In the image above, the black points with
error bars show the pulse period derivative (or spin-down rate) for
PSR B1828−11. Blue solid lines indicate the observing epochs for the
Parkes and Green Bank Telescope data presented in a recent paper by
Stairs et al. The red solid line is a fit to the black points
incorporating two harmonically related sinusoids of decreasing period
as well as a linear slope. The cyan solid line indicates the starting
point of data included in the fit. Full results are published in
the paper published in
Monthly Notices of the Royal Astronomical Society.
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