Astronomers have discovered the Milky Way’s disk is warped and twisted, not flat like a pancake. The authors hypothesize that as the Milky Way’s inner disk of stars rotates, it drags on the outer disk, distorting our galaxy’s flat spiral

Astronomers have discovered the Milky Way's disk is warped and twisted, not flat like a pancake. The authors hypothesize that as the Milky Way’s inner disk of stars rotates, it drags on the outer disk, distorting our galaxy's flat spiral

  • The shape of the Milky Way, usually pictured as a flat spiral, may actually be more like a warped and twisted disk.
  • The 1,339 stars are all Cepheid variables, a type of pulsating star whose intrinsic brightness depends on how long it takes to vary from bright to dim and back again.
  • Since a Cepheid’s period tells astronomers how bright the star truly is, measuring how bright it appears lets astronomers draw an accurate distance map.
  • By measuring their distances and then plotting those stars in 3D, the team from Macquarie University in Australia and the Chinese Academy of Sciences have produced a new map of the Milky Way, one that shows a distinct twist.
  • Astronomers have known for decades that the gas disk in the Milky Way is warped.
  • The gas also extends nearly twice as far as the stars in the visible disk and it flares out, extending both higher and lower at the edges than the flat pancake of stars.
  • While the recent study focused on making the map, not explaining it, the authors hypothesize that as the Milky Way’s inner disk of stars rotates, it drags on the outer disk as well, distorting the flat spiral.