Astronomers Need More Observations to Explain Pulsars Available to Purchase

More information is available now on the four pulsed radio sources discovered last December at Cambridge, but no new ones have been found and theoreticians still argue about what they are. Called “pulsars,” these sources emit pulses at radio wavelengths with remarkably constant repetition intervals that range in the four known cases from 0.25 to 1.33 sec (PHYSICS TODAY, May, page 75). We recently visited the Mullard Radio Observatory at Cambridge and the Nuffield Radio Observatory of the University of Manchester at Jodrell Bank to talk to astronomers engaged in these observations.