An international group of astronomers has created the most detailed three-dimensional map of the Milky Way, revealing that the galaxy is not flat but has an S-shaped structure, resembling a warped disk.
A glimpse of the Milky Way in Hungary. Photo: EPA.
The research, published in the journal Science, shows that the curvature and twist of this galactic disk are quite noticeable and resemble a hat when observed closely.
To create a more detailed and comprehensive 3D map of the Milky Way, which is home to over 100,000 stars, including our Sun, astronomers focused their observations on more than 2,400 of the brightest stars in the Milky Way known as Cepheid variable stars. They used the Vácsava Telescope at the Las Campanas Observatory in the Andes Mountains of Chile.
Cepheid variable stars are celestial objects that exhibit regular changes in brightness over time. These stars are exceptionally large and luminous, ranging from 100 to 10,000 times the brightness of the Sun, making them observable throughout the galaxy, even through interstellar gas and dust clouds. What’s more, they are relatively young stars, less than 400 million years old, which means they are still located close to where they were born.
Astronomers calculated the distances to these stars by comparing their actual brightness to the brightness observed from Earth and by monitoring the stable pulsations of these more than 2,400 stars. They determined the positions of these stars in the Milky Way’s 3D model.
Dorota Skowron, the lead researcher and an astronomer at the University of Warsaw (Poland), stated, “This is the first time we can use individual objects to show this in three dimensions.”
This new research provides a completely new and specific perspective on the Milky Way, in contrast to the previous understanding of its spiral shape and structure, which was based on indirect measurements to landmarks and extrapolations of celestial objects from other galaxies in the vast universe.