Dazzling white dwarf pulsar discovery is the first of its kind

[Buster's Uncle]

Dazzling white dwarf pulsar discovery is the first of its kind
After searching since the 1960s, astronomers have finally found the hypothesised white dwarf pulsar.
CNET
by  Michelle Starr  February 8, 2017 8:40 PM PST



Artistic impression of AR Scorpii.  University of Warwick



First discovered in 1967, a pulsar is a type of star that rotates, sending out beams of electromagnetic radiation. As it rotates, it flashes brightly like a lighthouse in a pulsing rhythm, hence its name.

Since that 1967 discovery, all pulsars in the sky have been neutron stars, the last stages of a dying star after supernova before it collapses into a black hole. However, researchers hypothesised that white dwarfs -- dying stars not massive enough to become neutron stars -- could also become pulsars.

Tom Marsh and Boris Gänsicke of the University of Warwick's Astrophysics Group, and David Buckley from the South African Astronomical Observatory, have just found proof of this in the form of a binary star called AR Scorpii, located in the constellation of Scorpius, just 380 light-years from Earth.

The pair consists of a red dwarf, and in proximity, a white dwarf pulsar the size of the Earth but 200,000 times denser, lashing its neighbour with electrical energy and particles. And that proximity is close -- a mere 1.4 million kilometres, three times the distance between the Earth and the moon.

The white dwarf's rotational period is just two minutes, and the orbital period of the pair is three hours and 36 minutes.

The team have published their historic findings in the journal Nature Astronomy.


https://www.cnet.com/news/elusive-white-dwarf-pulsar-discovery-is-the-first-of-its-kind