The first pulsar was discovered in 1967. It was discovered by Jocelyn Bell Burnell and Antony Hewish. They worked at the University of Cambridge. The observed emission had pulses separated by 1.33 seconds. The pulses all came from the same place in the sky. The source kept to sidereal time. At first, they did not understand why pulsars have a regular change in the strength of radiation. The word "pulsar" is short for "pulsating star".