New white dwarf pulsar is one of the rarest stars to be discovered in the universe

By Ansharah Shakil, August 12 2023—

The first white dwarf pulsar was discovered in 2016 when it was the first of its kind ever to be found in the universe. Back then, finding one was a major accomplishment. Now, seven years later, a second white dwarf pulsar has been found. 

Pulsars are spinning neutron stars and remnants of massive stars. White dwarfs are the most common stellar fossils, formed when stars with large masses run out of nuclear fuel. Our very own sun will experience this in around 4.5 billion years when it will eventually become a white dwarf as its life comes to an end. The white dwarf pulsar is a white dwarf in a binary system which beams particles and electromagnetic radiation upon its neighbouring red dwarf star, with an extremely strong magnetic field powering it. 

White dwarfs are a fascinating and common phenomenon, but the white dwarf pulsar is far more rare, which is why it’s exciting that there’s now a second of its kind. It’s confirmed as a white dwarf pulsar by Ingrid Pelisoli and her colleagues at the University of Warwick along with a second independent study led by Alex Schwope of Leibniz Institute for Astrophysics called J191213.72-441045.1, or J1912-4410 for short, this white dwarf pulsar follows the first one, named AR Scorpii for its proximity to the constellation Scorpius. Research on AR Scorpii suggested it fit the dynamo model: that is, when we look at how it cools, allowing heat to escape from the interior density changes, its interior could start a dynamo.

J1912-4410 doesn’t have as catchy of a name as AR Scorpii, but its characteristics match the dynamo model suggested by AR Scorpii. The camera that discovered it is called the ULTRACAM. Research telescopes including optical telescopes at the South African Astronomical Observatory (SAAO), the Southern African Large Telescope and the MeerKAT radio telescope were also used during the process.

Scientists are now able to delve further into researching white dwarf pulsars, support some proposed theories and models and most importantly establish white dwarf pulsars as a class with a possibility of more like J1912-4410 being discovered. The successful scientific discovery of J1912-4410 encourages the advent of new research. More about this can be read in Nature Astronomy.