The pulsar is about 10 times brighter than any other specimen observed outside our Milky Way.

Researchers have encountered a special pulsar using ‘astronomical sunglasses’. It is the brightest found to date. “This is a wonderful surprise,” said researcher Yuanming Wang. “With the newest telescopes we have access to today, it is really possible to reveal new pulsars.”

What are pulsars?
A pulsar is the rapidly spinning remnant of an exploded massive star. The remainder has a powerful rotating magnetic field that generates an electric field. That electric field accelerates charged particles near the pulsar’s magnetic poles, creating a radiation beam at both poles. Because that pulsar also rotates very quickly, the radiation beams – just like the light beams from a lighthouse – swing through space. And when such a radiation beam is briefly aimed at the earth, it results in a flash.

The first pulsar was observed in the 1960s. Since then, astronomers have discovered more than 2,000 of these exotic objects. Despite the fact that astronomers have already detected quite a few pulsars in the universe, they are still puzzling. For example, researchers are still unable to properly grasp the diverse behaviors of pulsars, as well as the nature of the stars from which they originate. And so the hunt for new ones continues.

New method

In the new study the researchers used the industry-leading ASKAP radio telescope, which excels in wide-space scanning and observations from the MeerKAT radio telescope in South Africa. The team then put on the telescope a kind of ‘astronomical sunglasses’ that can collect polarized light. And that’s new. Traditional methods of finding pulsars involve looking for “flickers” in telescope data. However, which ones are too fast or too slow can be easily overlooked this way. By looking for polarized light instead, pulsars outside the standard range can be detected.

Brightest pulsar ever

The new method leads to an astonishing discovery. Because thanks to this new method, the astronomers stumbled upon a never-before-seen pulsar that surprisingly turns out to be the brightest ever.

The newly discovered pulsar seen with ‘sunglasses’ on and ‘sunglasses’ off. Image: Yuanming Wang

The bright spot had already been noticed before. But until now, astronomers thought it was a distant galaxy. However, nothing turns out to be less true. Because the supposedly remote galaxy actually turns out to be a pulsar, which is as much as 10 times brighter than any other object observed outside our Milky Way. “Because of its unusual properties, this pulsar has been overlooked in previous studies, despite its brightness,” said study co-author Tara Murphy.

It is promising that the first pulsar detected using the new method is immediately a special one. “This is the first time we’ve searched for the polarization of a pulsar in a systematic and routine way,” Murphy said. The findings therefore show what we can expect in the future if this method is used more often. In addition, it demonstrates what today’s telescopes are capable of and how researchers continue to find new ways to answer grand questions about the still enigmatic universe.