The new Low Frequency Array (LOFAR) telescope has joined with the Lovell Telescope at Jodrell Bank observatory and the Effelsberg telescope at the Max Planck Institute for Radio Astronomy in Germany to make simultaneous, multi-wavelength observations of pulsars.
Pulsars are rapidly rotating neutron stars. Their magnetic fields are misaligned with their axes of rotation and so their poles flash towards and away from us (if properly aligned) like the beam of a lighthouse. Charged particles trapped within the magnetic field are accelerated by the rotation and emit synchrotron radiation at different wavelengths at the poles. The result is a constant radio pulsing signal that when first discovered was thought too regular to be natural, though it was soon realised to be so.
The frequency at which the particles emit radiation changes depending on where they are along the magnetic field, meaning looking at different wavelengths probes different parts of the magnetic environment of the pulsar.
Further details of the experiment, which looked at six pulsars, are contained in this press release.