WASHINGTON, Aug. 1 -- An international team of astronomers charted the most detailed three-dimensional map of the Milky Way, revealing that the galaxy is not flat but has an S-shaped, warped stellar disc.

The study published on Thursday online in the journal Science showed that the warping amount of the twisted galactic disk was pronounced and looked like a fascinator hat.

"The stars 60,000 light years away from the Milky Way's centre are as far as 4,500 light years above or below the galactic plane. This is a big percentage," said the paper's first author Dorota Skowron with the University of Warsaw in a statement.

Researchers from Poland, the United States and Britain directly measured the distance from the sun to 2,400 pulsating stars called Cepheids scattered across the Milky Way and charted the Milky Way on a larger scale than ever before.

Cepheids are bodies whose brightness varies in a regular cycle over time. Using the periodic variations in their brightness, the distances to these stars can be precisely determined.

By determining the 3D coordinates of each distant pulsing star relative to the sun, the researchers built a large-scale 3D model of the Milky Way galaxy.

The previous understanding of the spiral shape and structure of the Milky Way is built upon indirect measurements to celestial landmarks and inferences based on other galaxies in the universe.

"This is the first time we can use individual objects to show this in three dimensions," said Skowron.

The new map illustrates and helps constrain the previously observed shape of the galaxy's warped stellar disc.