Jul 282016
According to:
A radio pulsing white dwarf binary star
The star AR Scorpii (~116 parsecs distance), previously thought to be a single variable star, turns out to be two stars: a small (roughly 0.3 solar mass) regular M5-class star and a rapidly spinning white dwarf (roughly 0.8 solar mass). The white dwarf, unlike pretty much all the other known white dwarfs, is emitting beams of radiation; the alignment of such is that they strike the other star. And thus every 1.97 minutes the star convulses and brightens. Brights by as much as a factor of *four* inside of thirty seconds. The orbital period of the binary system is a brisk 3.56 hours. The two are close enough that the main sequence star would be distorted into an egg-shape.