Motions of stars in neighboring Large Magellanic Cloud shed light on galaxy formation

Scientists have mapped the motions of stars within the Milky Way's companion galaxy, the Large Magellanic Cloud, revealing new clues about barred galaxies.

The findings could offer new insight into the processes that shape and form the structures of these galaxies, which contain bar-like bands of stars, researchers report in a new study. Located about 163,000 light-years from Earth, the Large Magellanic Cloud (LMC) — a satellite dwarf galaxy of the Milky Way — is among the closest galaxies to Earth and is visible to the naked eye as a faint cloud in the Southern Hemisphere sky. The LMC is considered an irregular galaxy, given its single spiral arm and stellar bar structure, which is offset from the galaxy's center.

Stellar bar structures are a common feature in spiral galaxies. Scientists think these structures form when small perturbations within the stellar disk strip stars from their circular motions and push them into elongated orbits.. "A specific type of these orbits are the ones that are aligned with the major axis of the bar," lead author Florian Niederhofer, a researcher at the Leibniz Institute for Astrophysics Potsdam, said in a statement. "These are considered to be the 'backbone' of stellar bars and provide the main support of the bar structure."