NGC253: Also known as the "Sculptor Galaxy," this is an intermediate spiral (meaning between a barred-spiral and an unbarred-spiral) galaxy, presenting to us almost edge-on; it is
visually within the constellation Sculptor. It is part of the Sculptor Group of galaxies (galaxies gravitationally bound to one another). The Sculptor Galaxy is a "starburst galaxy,"
which is a galaxy undergoing intense star formation (in this case mostly near its core). The bright blue dots are clusters of bright young stars. NGC253 is relatively close to us, about 11
million light years away. It measures about 70,000 light years across (about 70% of what our Milky Way measures); at that distance, it subtends an angle of 27.5 arcminutes.
One of my favorite things about astrophotography is how many galaxies there are out there, as shown by practically any reasonably-deep deep-sky image; the full-resolution version of this image has dozens of tiny "background" galaxies showing, many of them face-on spiral galaxies.
Copyright 2015 Mark de Regt