Whirlpool Galaxy. In 1845, Lord Rosse discovered the spiral structure and made a simple study of its structure. The galaxy has a companion (NGC 5195) that is, as it seems, connected to one of the spiral branch. Some try to prove that it is more likely an effect of line of sighting than a direct contact, although the minor companion has definitely had a gravitational influence on the structure of the main galaxy. Our answer - It is a moment of reformation of two Stellar Systems into one.