Hyperactive galaxy NGC 7673

The disturbed spiral galaxy NGC 7673 is ablaze with the light from millions of new stars. Each of its infant giant blue star clusters shines 100 times as brightly in the ultraviolet as similar immense star clusters in our own Galaxy. Scientists studying this object have two pressing questions: "What has triggered this enormous burst of star formation and how will this galaxy evolve in the future?"

Telltale patches of blue light are signs of the formation of millions of new stars in the tangled spiral galaxy NGC 7673. Each of the bluish areas in this image consists of immense star clusters containing thousands of young stars. These clusters lie on the spiral arms of NGC 7673 and so emphasise its somewhat ragged look. This image, taken from Earth orbit by the ESA/NASA Hubble Space Telescope in 1996 and 1997, also shows two other galaxies seen in the background of the image, to the left and right of NGC 7673. These galaxies are further away and so appear redder, due to their higher redshift, an effect caused by the expansion of the Universe.

The youngest blue stars in NGC 7673 are blazing with intense ultraviolet radiation. Each star cluster radiates 100 times more ultraviolet light than the famous Tarantula Nebula (30 Doradus), the largest star-forming region known in the local group of galaxies.