Scientists at the Max Planck Institute for Extraterrestrial Physics in Germany have discovered a new structure in the Milky Way. Researchers have identified an inner ring of stars with a high metal content outside the bar — a central elongated structure of stars and gas. This is reported in an article published in the journal Astronomy & Astrophysics.
The researchers analyzed data obtained during observations of the Gaia Space Telescope and APOGEE, a large—scale spectroscopic survey of stars conducted in the near infrared range. This made it possible to determine the orbits of more than 30 thousand stars located in the inner part of the Milky Way galaxy.
Inside the central bridge, the researchers found a ring structure, where the age of the stars is less than that of the environment, and is about seven billion years old. They also have a higher metallicity, that is, they contain more elements heavier than hydrogen. A similar structure has previously been observed in other galaxies. At the same time, it is still unknown whether there is a connection between the ring and the spiral arms of the galaxy, and whether interstellar gas is currently being directed into the thin stellar ring.