Mystery Of Twin Star System Which ‘Flashes’ Every Two Minutes

Amateur astronomers working with a team of University of Warwick scientists have solved the mystery of a weird star system which ‘pulses’ every two minutes.

The star system AR Scorpii, or AR Sco for short, lies in the constellation of Scorpius, 380 light years from Earth - and contains a white dwarf the size of Earth but with 200,000 the mass.

Astronomers using the NASA/ESA Hubble Space Telescope, along with other telescopes worked out that the rapidly spinning white dwarf star is powering electrons up to almost the speed of light.

These high energy particles release blasts of radiation that lash the companion red dwarf star, and cause the entire system to pulse dramatically every 1.97 minutes with radiation ranging from the ultraviolet to radio.

Lead researcher Tom Marsh of the University of Warwick’s Astrophysics Group commented: ‘AR Scorpii was discovered over 40 years ago, but its true nature was not suspected until we started observing it in June 2015. We realised we were seeing something extraordinary the more we progressed with our observations.’

But the system remains mysterious - no one knows where the stream of electrons comes from it is not clear whether it is associated with the white dwarf, or its cooler companion.

Boris Gänsicke, co-author of the new study, also at the University of Warwick, says, ‘We’ve known about pulsing neutron stars for nearly fifty years, and some theories predicted white dwarfs could show similar behaviour.

‘It’s very exciting that we have discovered such a system, and it has been a fantastic example of amateur astronomers and academics working together.’