The “Cartwheel Galaxy” lies at an enormous distance – about 500 million ly away. It would show little detail at this distance except for its size (150,000 ly across) and high surface brightness. This ring galaxy is the product of a “bull’s-eye” pass through collision with another galaxy about 300 million years ago. Currently, the identity of the invader, among the 3 smaller galaxies in the picture, is believed to be the spiral that lies furthest out at about 5:00.

The Cartwheel’s “spokes” are thought to be early signs that the galaxy is reforming itself again into a spiral pattern following the collision.

PlaneWave 12.5″ Astrograph with an ST11000 camera, Astrodon filters, and ASA gearless mount. F/8 LRGB (47/8min L, 8/8min 2×2 each RGB).