August 2, 2001: The Hubble telescope has captured an image of an unusual edge-on galaxy, revealing remarkable details of its warped dusty disk and showing how colliding galaxies spawn the formation of new generations of stars. The dust and spiral arms of normal spiral galaxies, like our own Milky Way, appear flat when viewed edge-on. This Hubble Heritage image of ESO 510-G13 shows a galaxy that, by contrast, has an unusual twisted disk structure, first seen in ground-based photographs.
The strong warping of the disk indicates that ESO 510-G13 has recently undergone a collision with a nearby galaxy and is in the process of swallowing it. Gravitational forces distort the structures of the galaxies as their stars, gas, and dust merge together in a process that takes millions of years. Eventually the disturbances will die out, and ESO 510-G13 will become a normal-appearing single galaxy. In the outer regions of ESO 510-G13, especially on the right-hand side of the image, the twisted disk contains not only dark dust but also bright clouds of blue stars. The blue stars indicate that hot, young stars are being formed in the disk. Astronomers believe that the formation of new stars may be triggered by collisions between galaxies, which compresses interstellar clouds.