The Small Magellanic Cloud’s stars do not rotate around its center due to a past collision with the Large Magellanic Cloud, according to a study published in The Astrophysical Journal.
How the collision disrupted stellar motion
Researchers from the University of Arizona found that several hundred million years ago, the Small Magellanic Cloud passed directly through the disk of the Large Magellanic Cloud, disrupting its structure and sending stars into chaotic motion.
What this means for using the SMC as a galactic model
The discovery raises concerns about using the Small Magellanic Cloud as a stable reference for studying galaxy evolution, as its current state reflects ongoing transformation rather than equilibrium.
Why do the SMC’s stars not rotate orderly?
The gravitational forces from the collision with the Large Magellanic Cloud disrupted the Small Magellanic Cloud’s structure, preventing the formation of a rotating disk.
How long ago did the collision occur?
The study indicates the Small Magellanic Cloud passed through the Large Magellanic Cloud’s disk several hundred million years ago.