Record-breaking pulsar astounds astronomers

6 Oct 2023

Illustration of the Vela pulsar. Image: Science Communication Lab for DESY

The energy detected from the pulsar’s gamma rays was 10trn times the energy of visible light and could alter our understanding of how these ‘cosmic lighthouses’ work.

Scientists claim to have detected the highest energy gamma rays ever from a pulsar, which could challenge our current knowledge on these cosmic events.

The energy from these gamma rays was clocked in at 20 tera-electronvolts, which is 10trn times the energy of visible light, according to scientists using the High Energy Stereoscopic System (HESS) Observatory in Namibia.

A pulsar is a type of neutron star – which is the remnant of a star that spectacularly exploded in a supernova. Neutron stars are considered pulsars when they spin extremely fast, releasing rotating beams of electromagnetic radiation.

Most neutron stars are detected as pulsars due to the regular pulses of radiation they emit, according to NASA. They are sometimes described as ‘cosmic lighthouses’ due to these regular flashes.

In the recent study, scientists looked at the Vela pulsar – which rotates about 11 times per second – using the HESS Observatory.

The researchers said this observatory detected a new radiation component at much higher energy than previously recorded. Prof Christo Venter from the North-West University in South Africa, said the result was “about 200 times more energetic than all radiation ever detected before from this object”.

The result has left the team confused, as traditional schemes can’t explain the observations – according to Arache Djannati-Atai from the French Astroparticle and Cosmology (APC) laboratory.

“This result challenges our previous knowledge of pulsars and requires a rethinking of how these natural accelerators work,” Djannati-Atai said.

“This discovery opens a new observation window for detection of other pulsars in the tens of teraelectronvolt range with current and upcoming more sensitive gamma-ray telescopes, hence paving the way for a better understanding of the extreme acceleration processes in highly magnetised astrophysical objects.”

In February, Dr Mark Kennedy from University College Cork spoke about the research he is involved in that answers, and raises, questions about neutron stars.

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Leigh Mc Gowran is a journalist with Silicon Republic