Discovery of the First Pulsar

On November 28, 1967, northern hemisphere local time, astronomer Jocelyn Bell Burnell, a graduate student at the University of Cambridge, identified the first pulsar, a highly magnetized rotating neutron star emitting beams of electromagnetic radiation. This detection occurred while working under the supervision of Antony Hewish on a study concerning interplanetary scintillation using a radio telescope at the Mullard Radio Astronomy Observatory.

Background

The scientific community at the time had not observed or confirmed the existence of pulsars, despite theoretical predictions of such phenomena. Neutron stars were hypothesized remnants of supernovae, with properties distinct from any celestial objects yet identified.

The Discovery

Bell Burnell noticed regular pulses of radio waves that appeared every 1.33 seconds from a single point in the sky. These signals, initially referred to as “LGM-1” (Little Green Men), suggested a non-terrestrial and non-human origin. Understanding that the signals were too regular to be artificial, the team investigated further to confirm their celestial nature.

Confirmation and Analysis

Working diligently to ensure the signal was not due to terrestrial interference, Bell Burnell and Hewish conclusively identified the pulsar, which was later cataloged as PSR B1919+21. This discovery provided concrete evidence of rotating neutron stars and opened a new field of research in astrophysics.

Implications

The confirmation of pulsars contributed significantly to the understanding of stellar evolution and neutron stars. Pulsars became vital tools for probing the interstellar medium and testing theories of gravity and relativistic physics. Antony Hewish was awarded the Nobel Prize in Physics in 1974 for his pioneering work, a decision that sparked controversy because Jocelyn Bell Burnell was not included, despite her crucial role in the discovery.

Legacy

The discovery of the first pulsar marked a pivotal moment in astrophysics, enhancing understanding of the universe’s fundamental forces and structures. It laid the groundwork for future astronomical studies, significantly advancing knowledge in fields such as neutron star behavior and gravitational waves.