August 2, 2022

The Cartwheel Galaxy (also known as ESO 350-40 or PGC 2248) is a lenticular galaxy and ring galaxy about 500 million light-years away in the constellation Sculptor. It is an estimated 150,000 light-years diameter, and has a mass of about 2.9–4.8 × 1000000000 solar masses; its outer ring has a circular velocity of 217 km/s.

NASA’s James Webb Space Telescope has peered into the chaos of the Cartwheel Galaxy, revealing new details about star formation and the galaxy’s central black hole. Webb’s powerful infrared gaze produced this detailed image of the Cartwheel and two smaller companion galaxies against a backdrop of many other galaxies. This image provides a new view of how the Cartwheel Galaxy has changed over billions of years.

The Cartwheel Galaxy, located about 500 million light-years away in the Sculptor constellation, is a rare sight. Its appearance, much like that of the wheel of a wagon, is the result of an intense event – a high-speed collision between a large spiral galaxy and a smaller galaxy not visible in this image. Collisions of galactic proportions cause a cascade of different, smaller events between the galaxies involved; the Cartwheel is no exception.

The collision most notably affected the galaxy’s shape and structure. The Cartwheel Galaxy sports two rings — a bright inner ring and a surrounding, colorful ring. These two rings expand outwards from the center of the collision, like ripples in a pond after a stone is tossed into it. Because of these distinctive features, astronomers call this a “ring galaxy,” a structure less common than spiral galaxies like our Milky Way.