Arp 299 colliding galaxies, composite radio-optical image. This colliding pair of galaxies is a region of vigorous star formation. Observations with the Very Large Array (VLA) showed a region of prolific star formation near the nucleus of one of the colliding galaxies. In this image, the L-band radio data (in pink) from the Very Large Array (VLA) have been merged with visible light images from the Hubble Space Telescope (HST). Arp 299 is around 134 million light years distant, in the constellation of Ursa Major.