NGC 5474とは 意味・読み方・使い方

NGC 5474 is a peculiar dwarf galaxy in the constellation Ursa Major. It is one of several companion galaxies of the Pinwheel Galaxy (M101), a grand-design spiral galaxy. Among the Pinwheel Galaxy's companions, this galaxy is the closest to the Pinwheel Galaxy itself. The gravitational interaction between NGC 5474 and the Pinwheel Galaxy have strongly distorted the galaxy. As a result, the disk is offset relative to the nucleus. The star formation in this galaxy (as traced by hydrogen spectral line emission) is also offset from the nucleus. NGC 5474 shows some signs of a spiral structure. As a result, this galaxy is often classified as a dwarf spiral galaxy, a relative rare group of dwarf galaxies.