Most of the stars in the Andromeda galaxy were shaken by a merger with another galaxy. In this respect informs space.com.tr
The Andromeda Galaxy, often referred to as a nebula in the mid-20th century, is 2.4–2.7 million light-years from the Milky Way. year. It is the closest large galaxy to Earth, and if it were brighter, its apparent size in the sky would be several times the diameter of the Moon.
Now astronomers have new evidence that most of the stars in this galaxy migrated here from the neighboring galaxy. The study was carried out using the DESI (Dark Energy Spectroscopic Instrument) instrument powered by Kitt Peak National Observatory’s 4-meter telescope. The instrument made it possible to observe 7500 stars of the Andromeda galaxy and measure their radial velocity (as they move away from or approaching Earth). In the drawing above, each dot represents a star and its color represents the measured velocity without a red (or blue) shift. Analysis of their movements showed that many of them formed in another galaxy that merged with the Andromeda galaxy about 2 billion years ago.
“We’ve never seen signs of this so clearly in the movement of stars before, and we’ve never seen some structures resulting from merging,” said Sergey Koposov, one of the study’s authors, from the University of Edinburgh. “We now see that the history of the Andromeda galaxy is similar to the history of our own galaxy, the Milky Way. The inner halos of both galaxies are dominated by a single major migration event.”
Formerly Hubble Telescope sent Photograph of the bright star cluster NGC 376.