This spectacular image from the NASA/ESA Hubble Space Telescope shows the trailing arms of NGC 2276, a spiral galaxy 120 million light-years away in the constellation of Cepheus. At first glance, the delicate tracery of bright spiral arms and dark dust lanes resembles countless other spiral galaxies. A closer look reveals a strangely lopsided galaxy shaped by gravitational interaction and intense star formation.
This striking image showcases the unusually contorted appearance of NGC 2276, an appearance caused by two different astrophysical interactions — one with the superheated gas pervading galaxy clusters, and one with a nearby galactic neighbor.
The interaction of NGC 2276 with the intracluster medium — the superheated gas lying between the galaxies in galaxy clusters — has ignited a burst of star formation along one edge of the galaxy. This wave of star formation is visible as the bright, blue-tinged glow of newly formed massive stars towards the left side of this image, and gives the galaxy a strangely lopsided appearance. NGC 2276’s recent burst of star formation is also related to the appearance of more exotic inhabitants — black holes and neutron stars in binary systems.
NGC 2276 is by no means the only galaxy with a strange appearance. The Atlas of Peculiar Galaxies — a catalog of unusual galaxies published in 1966 — contains a menagerie of weird and wonderful galaxies, including spectacular galaxy mergers, ring-shaped galaxies, and other galactic oddities. As befits an unusually contorted galaxy, NGC 2276 has the distinction of being listed in the Atlas of Peculiar Galaxies twice — once for its lopsided spiral arms and once for its interaction with its smaller neighbor NGC 2300.