The 3D structure of the Milky Way

By calculating the distance from the sun to thousands of pulsating stars across the Milky Way, astronomers have now charted our galaxy in 3D on a larger scale than ever before. Using the Optical Gravitational Lensing Experiment, which monitors the brightness of nearly 2 billion stars, the scientists charted the distance between the sun and more than 2,400 Cepheids throughout the Milky Way. These findings helped the astronomers build a large-scale 3D map of the Milky Way. This is the first such map based on directly measured distances to thousands of celestial landmarks across the galaxy.
The new map helped reveal more details on distortions that astronomers had previously detected in the shape of the Milky Way. Specifically, the galaxy's disk is not flat at distances greater than 25,000 light-years from the galactic core, but warped. This warping was potentially caused by the galaxy's interactions with satellite galaxies, intergalactic gas or dark matter.