An ancient collision reshaped the Cartwheel Galaxy structure and sparked vast waves of star formation across the cosmos, according to an observation released on August 2, 2022.
The James Webb Space Telescope combined data from two infrared instruments to capture the system in extraordinary detail.
Located roughly 500 million light-years away in the constellation Sculptor, the Cartwheel belongs to an unusual class known as ring galaxies. Its appearance differs sharply from the familiar spiral arms of the Milky Way. Astronomers attribute that shape to a high-speed impact between a large spiral galaxy and a smaller companion outside the frame.
The encounter sent disturbances outward through the larger galaxy, producing a bright inner ring and a broader outer ring. NASA compares the expansion to ripples spreading across a pond after a stone hits the water. Those enormous ripples have reshaped the system over hundreds of millions of years.
Earlier observations from the Hubble Space Telescope had revealed the structure, but dust obscures parts of the galaxy in visible light. The James Webb Space Telescope observes infrared wavelengths to examine stars hidden behind that dusty veil. Its Near-Infrared Camera reveals points of starlight and pockets of active formation.
The outer ring marks a region where the collision effects continue to unfold as it expands into surrounding gas. NASA estimates that this outer structure has been expanding for about 440 million years. Star formation and supernovas help make it an active part of the system.
The center holds its own concentrations of activity with hot dust filling the bright core. Luminous areas contain enormous clusters of young stars. Blue points mark individual stars, while bright red strands trace glowing dust and curved spokes that connect the inner and outer portions.
A high-speed collision between a large spiral galaxy and a smaller intruder triggered the expanding ripples.
The Cartwheel Galaxy lies roughly 500 million light-years away in the constellation Sculptor.
Colors translate infrared observations into a visible format, where blue points mark star formation and red strands trace glowing dust.
The Cartwheel’s eventual shape remains uncertain as its expanding rings capture a galaxy still in transition. Across its bright rim and dusty spokes, the system records how one encounter influences a galaxy for hundreds of millions of years.
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