50th Anniversary of the Discovery of Pulsars


From Monday 4th to Friday 8th September, Jodrell Bank Observatory is hosting the 337th IAU Symposium meeting at the Jodrell Bank Discovery Centre. As well as the 60th anniversary of the Lovell Telescope, the year 2017 marks the 50th anniversary of the discovery of pulsars – which are rapidly rotating neutron stars, the remnants of some of the most spectacular explosions in the universe. The meeting, “Pulsar Astrophysics: The Next 50 Years” aims to pause, reflect on the successes of the last quarter-century, and look ahead to the future.

When, on November 28th 1967, the first pulsar was discovered by Dame Jocelyn Bell Burnell, its signal appeared as a pulse, repeating every 1.33 seconds, completely periodically]. It was playfully nicknamed LGM-1 (“little green men”), and as more of these objects were discovered all over the sky, it became clear that pulsars were an exciting glimpse into the Universe in their own right – even if they weren’t signs of an alien civilisation. Many agreed, and in 1974 the discovery of pulsars secured astronomers with their first Nobel Prize in Physics – a controversial move as Jocelyn Bell was not one of them.

It is now known that pulsars are the dead hearts of giant stars. At the end of their lives, massive stars explode in dramatic supernova which can outshine entire galaxies. These titanic explosions compress stars’ cores down to extreme densities and may become neutron stars – if it were possible to scoop up a teaspoon of material from a neutron star it would weigh about 10 million tons! Pulsars are neutron stars: as the star’s core shrinks it spins faster and faster, and particles which accelerate along their magnetic poles release electromagnetic radiation in beams. The end result is a tiny, incredibly dense core producing radiation from two poles, which sweep around with each rotation like a cosmic lighthouse. The pulses seen every 1.33 seconds by Jocelyn Bell were LGM-1’s beams every time they swept by Earth.

Fifty years and a thousand pulsars later, scientists are just as excited about them. Their extreme natures allow us to test theories of gravity, probe spacetime, and learn about the nature of matter and the structure of our own Milky Way. Their stability and longevity could, in the distant future, be useful for navigation during deep space travel. We’re developing new ways to search for them – in 2016 Jodrell Bank collaborated with Zooniverse and the BBC to help citizen scientists all over the world look for new pulsars – and this week’s meeting will cover next generation pulsar searches, future uses for these fascinating objects, and more. Guest speakers include none other than Dame Jocelyn Bell Burnell herself, in addition to many who have played vital roles in making pulsar science as diverse as it is today.

You can discover more about pulsars at our Girls Night Out Pulsar Party on 28th September. The event will be led by Dr. Sally Cooper, one of Jodrell Bank Centre for Astrophysics’ resident pulsar hunters, the evening will include an inspiring introductory talk, a Q&A session with the pulsar hunting team, some hands-on pulsar model making, and a host of interactive experiments in our very own mini pulsar fair.