Image of the week: An irregular galaxy

Blue and gold
Galaxy 149-3, which appears as a random sprinkling of stars in this Hubble Space Telescope image, is an irregular galaxy.

While we are more familiar with spiral and elipitical (disc-shaped) galaxies — many of which can be seen in the background of this image — about a quarter of all galaxies are irregular. These galaxies are amorphous and asymmetrical, and lack an obvious centre.

Galaxy 149-3 is some 20 million light years away from Earth.