Vorontsov-Velyaminov Atlas of Interacting Galaxies

The catalog emphasizes galaxies that appear to interact or display unusual visual structures, including connected pairs, distorted systems, and peculiar groupings. Selection was based largely on photographic appearance rather than the detailed velocity measurements available today.

Boris Vorontsov-Velyaminov compiled the atlas in two main parts published in 1959 and 1977. Its objects are commonly identified with VV catalog numbers.

Both catalogs document galaxies with unusual forms, but they use different samples and numbering systems. Arp's atlas appeared in 1966, between the two principal parts of Vorontsov-Velyaminov's work.

No, apparent proximity in a photograph does not by itself prove that two galaxies are at the same distance. Modern redshift measurements and deeper imaging can confirm interactions or reveal chance line-of-sight alignments.