Brook et al. (2014) present the results of long-term monitoring of
PSR J0738-4042 with the Parkes telescope. They found that its pulse shape
changed multiple times between 1988 and 2012.
The torque, inferred via the derivative of the rotational
period, changes abruptly from 2005 September. This change is accompanied
by an emergent radio component that drifts with respect to the rest of
the pulse. No known intrinsic pulsar processes can explain these timing
and radio emission signatures. The data lead them to postulate that we are
witnessing an asteroid falling into the magnetosphere of the pulsar. -
Paul Brook is a student at Oxford University in the UK, and a co-supervised
student at CSIRO Astronomy and Space Science (CASS).