About 50 years ago, it became clear that galaxies are filled with an invisible substance that unifies everything we observe. This substance began to be called dark because it cannot be seen in the electromagnetic range and affects the environment only by gravity. Due to the diversity of dark matter in galaxies, the orbital speeds of stars do not decrease as their centers move away. But it turns out that everything is not so simple with the Milky Way.

Scientists from the Massachusetts Institute of Technology have conducted their own analysis of the distribution of velocities of stars in our galaxy depending on their distance from the center of the Milky Way. Using data from the European astrometric satellite “Gaia” and data from a sky survey using the Apache Point Observatory’s ground-based SDSS telescope and spectroscopic equipment of the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), scientists found: interior.

Data from more than 33,000 stars across the entire disk of the galaxy showed that the radial velocity of stars decreases significantly with distance from the center of the Milky Way, while the classical rotation curve of galaxies is an almost horizontal line as they move. away from the center. It turns out that it is easy for us to measure the rotation curves of distant and nearby galaxies, but we have barely learned to understand our own galaxy, and we have not learned it at all.

“What surprised us was that this curve remained flat for a certain distance and then started to fall, – said the authors of the study. “This means that the outer stars are rotating slightly slower than expected, which is a very strange result.”

“This result contradicts other measurements, – researchers continue. — A true understanding of this outcome will have profound consequences. “This could lead to the discovery of more hidden masses just beyond the galactic disk or to a revision of our galaxy’s state of equilibrium.”