Mysterious White Dwarf Pulsar with Radiation “Whip” Found
As our stargazing technology and techniques improve, it’s natural that we will begin to discover yet-unknown objects and celestial bodies in the vast reaches of space. Aside from the usual mysteries of the theoretical Planet 9 or ever-elusive dark matter, there might be entire forms of matter or energy we cannot yet perceive due to lacking the instruments or know-how to detect them. Earlier this month, researchers discovered a massive, superfast cloud of matter tearing through the Milky Way and don’t know how to explain its nature or origin. As if that wasn’t weird enough, a team of UK-based University of Warwick astronomers has reported the discovery of yet another strange cosmic object, the likes of which have never been seen.
According to their data published in Nature Research, this is the first known example of a white dwarf version of a pulsar. Pulsars are dense, fast-rotating neutron stars with a strong magnetic polarity causing them to emit beams of radiation as they rotate, similar to the light coming from rotating lighthouses.
Red dwarfs are similar to our Sun (a yellow dwarf): dense, hydrogen-based hot stars. White dwarfs, on the other hand, are the super-dense remnants of red and yellow dwarfs after they burn up and strip down to their cores. While red dwarf pulsars have been found, astronomers have suspected for fifty years that a white dwarf version might exist. That theory has finally been confirmed.
The star has been named AR Scorpii and is found in the constellation Scorpius just a galactic stone’s throw away, only 380 light-years from Earth. One of the strangest features of this bizarre star is a “lash” of radiation stretching far out into space which bombards is neighboring stars with electrical particles and radiation as the pulsar spins rapidly. According to University of Warwick professor Boris Gänsicke, the star is made even more unique by its incredibly powerful magnetic field:
AR Sco is like a gigantic dynamo: a magnet, size of the Earth, with a field that is ~10.000 stronger than any field we can produce in a laboratory, and it is rotating every two minutes. This generates an enormous electric current in the companion star, which then produces the variations in the light we detect.
The radiation emitted by this whip-like burst causes the entire system to appear to brighten and fade twice every two minutes and causes the electrons in the atmosphere of its closest neighbor, a red dwarf, to accelerate faster than the speed of light. This is the only such example of a ‘whip’ of radiation being shot out of a star in a single direction; most pulsars emit radiation in two opposite directions at once.