Lindsay-Shapley Ring Galaxy
Observed in 2004
The striking blue ring of the Lindsay-Shapley Ring Galaxy (AM 0644-741) is comprised of brilliant clusters of young, hot stars formed in a cosmic collision. About 150,000 light-years across, the ring structure is larger than our entire Milky Way galaxy, making it a truly massive cosmic structure. This rare ring galaxy formed when a smaller galaxy plunged through the center of a larger spiral galaxy, creating ripples of compressed gas that spread outward like waves on a pond. As these expanding waves of gas collided and compressed, they triggered intense bursts of star formation, creating the luminous blue ring of stellar nurseries we see today. The collision happened hundreds of millions of years ago, but the ring continues to expand outward, marking the ghostly outline of that ancient cosmic encounter and providing astronomers with valuable insights into galactic collisions and their role in triggering star formation.
Image credit: NASA, ESA, Hubble Space Telescope