The overdeveloped spiral arms of the tilted spiral galaxy NGC 772 dominate this image taken by the International Gemini Observatory, a project of the National Science Foundation NOIRLab. This stunning image shows the strange tilted spiral galaxy NGC 772, located more than 100 million light-years away in the constellation Aries.
Image shows NGC 772's overdeveloped spiral arm , which extends toward the left edge of the frame. The oversized spiral arms are due to NGC 772's unruly neighbor, NGC 770, a dwarf elliptical galaxy. Tidal interactions between NGC 772 and its little buddy twist and stretch one of the spiral galaxy's arms, giving it an unbalanced appearance in this image.
NGC 772 also lacks a bright center bar. Other spiral galaxies, such as the Andromeda Galaxy or our own Milky Way, have prominent central strips - large linear structures of gas, dust and countless stars. In the absence of a central bar, NGC 772's spiral arms sweep directly out from the galaxy's bright center.
This galaxy's unusual appearance has earned it the honor of appearing in the Atlas of Peculiar Galaxies, astronomer Halton Arp's curation of some of the weird and wonderful galaxies in the universe. The 338 galaxies in the atlas are a "rogue's gallery" of strange and unusual galaxy shapes, chosen to provide astronomers with a catalog of strange galaxy structures. Entries in the Atlas of Special Galaxies include galaxies with trailing tidal tails, rings, jets, breakaway segments, and a host of other structural peculiarities. NGC 772 is listed as Arp 78.
While the peculiarities of NGC 772 dominate this image, there are many galaxies lurking in the background. The bright spots and smudges in this image are actually distant galaxies - some closer examples can be broken down into characteristic spiral shapes. Every direction in the sky that astronomers point their telescopes contains a rich carpet of galaxies, with an estimated 2 trillion galaxies in total in our observable universe.
