Amazing it is: Inside dwarf star wars
Explore the bizarre binary-star phenomenon dubbed 'Dwarf-Star Wars: the revenge of the degenerates'.
More than 350 light years away from Earth, a binary star is 'lashing' its companion. Discovered using one of South Africa’s older telescopes, the researchers have called this bizarre binary-star phenomenon 'Dwarf-Star Wars: the revenge of the degenerates'.
White dwarf stars, also known as degenerate stars, are very dense, and this system’s white dwarf is lashing its companion with its magnetic field and a torrent of radiation. This white dwarf has a magnetic field of about 500-million Gauss.
For some context, the Earth’s magnetic field is about half a Gauss, and a fridge magnet is about 50 Gauss. The victim of this abuse is a red dwarf star, a small type of star and the most common in the Milky Way. The red and white dwarf form a binary star called AR Scorpii.
“This is a tug of war between two dwarf stars,” says Dr David Buckley, an astronomer at the South African Astronomical Observatory (SAAO). “Right now, the red dwarf is being slapped in the face once a minute by its rapidly rotating degenerate dwarf companion.”
These repeated bursts of radiation mean that the white dwarf is a pulsar, and were what allowed astronomers to detect this strange occurrence.
The paper, a collaboration between South African and United Kingdom scientists, was published in journal Nature Astronomy.
South Africa has become a hot bed of astronomy research, with the 64-dish MeerKAT radio telescope expected to come online later this year.
Construction of the Square Kilometre Array, which will be the largest radio telescope in the world, will start next year in both South Africa and Australia. Bizarre phenomenon such as this one could form part of these giant telescopes’ investigations to help us understand the cosmos.
“[But] this is a demonstration that forefront science can still be done with modest-sized telescopes and niche instruments,” says Buckley, who was lead author on the paper.
The 70-year old telescope is one of more than 20 on the SAAO’s site in Sutherland in the Northern Cape. The 10m Southern African Large Telescope also managed some additional followup optical observations after the discovery, Buckley says.
Regarding the future of this system, and whether the degenerate star will continue to beat its companion for the rest of time, University of the Free State’s Professor Pieter Meintjies, who co-authored the paper, said it was still “an open question”.