- Scientists found clues that the Milky Way grew by absorbing a dwarf galaxy Loki
- Loki was likely consumed during the Milky Way's early growth stages
- Study examined 20 metal-poor stars with unique chemical and orbital properties
Scientists have discovered new clues suggesting that the Milky Way grew larger billions of years ago by absorbing a smaller dwarf galaxy. The findings, published in the journal Monthly Notices of the Royal Astronomical Society, indicate that remnants of this ancient galaxy may still exist inside our own, reported NYPost.
Researchers have named the dwarf galaxy "Loki," after the Norse god of trickery. According to the study, Loki was likely consumed by the Milky Way during the early stages of the galaxy's growth.
The study suggests that the Milky Way expanded over time by merging with smaller star systems and dwarf galaxies. Loki is believed to have been one such dwarf galaxy made up of billions of stars.
Although large in scale, dwarf galaxies are much smaller than fully developed galaxies like the Milky Way, which contains hundreds of billions of stars.
Researchers compared the process to a galaxy consuming another galaxy during its early formation stages.
The discovery was made after scientists examined 20 metal-poor stars located on the Milky Way's galactic plane, the flat region where most of the galaxy's stars are found.
Metal-poor stars are considered extremely old and are believed to preserve chemical details from the environments in which they originally formed.
According to the researchers, these early building blocks merged together in the distant past, spreading their stars, gas, and dark matter into the growing proto-galaxy.
The team found that the chemical composition and orbital movements of the 20 stars were different from other metal-poor stars in the same region.
The stars reportedly contained traces of heavy elements produced during cosmic explosions such as supernovas and neutron star mergers.
However, researchers noted that the stars showed no signs of white dwarfs, which are remnants left behind after stars similar to the Sun run out of fuel and lose their outer layers.
Since white dwarfs take billions of years to form, scientists concluded that the stars likely came from a short-lived dwarf galaxy, identified in the study as Loki.
Researchers said the current sample size remains relatively small and larger datasets will be required before Loki's existence and structure can be fully confirmed and mapped.
