The disk of the Milky Way Galaxy disk may actually be rippled.
Credit: Heidi Newberg
Two ringlike structures of stars wrapping around the Milky Way’s outer disk now appear to belong to the disk itself.
The results, outlined in a new study, show that the disk is about 60 percent larger than previously thought. Not only do the results extend the size of the Milky Way, they also reveal a rippling pattern, which raises intriguing questions about what sent wavelike fluctuations rippling through the disk.
The researchers said the likely culprit was a dwarf galaxy. It might have plunged through the Milky Way’s center long ago, sparking the rippling patterns astronomers have now detected for the first time. [When Galaxies Collide: Photos of Great Galactic Crashes]
