Two merging galaxies’ immense gravity warps their arms into an embrace in a stunning new image from the Hubble T Space Telescope. The galaxy merger, known as Arp-Madore 417-391, was first described in the Arp-Madore catalogue of strange and unusual galaxies and is located about 670 million light years away in the Southern Hemisphere constellation of Eridanus. What makes this particular galaxy merger so compelling is the force of the two galaxies’ gravity twisting and distorting their shapes to form an irregular ring, with the nuclei of the two colliding galaxies left side by side on the bottom left of the structure.
Arp-Madore 417-391 is somewhat reminiscent of a different class of galactic structure known as a ring galaxy, the most famous of which is known as Hoag’s Object. These ring galaxies make up less than 0.1 per cent of all known galaxies. As the name suggests, ring galaxies have a pronounced ring structure rather than the arms of a typical spiral galaxy. Astronomers are still debating how these kinds of galaxies form, but galaxy collisions are considered a likely candidate.