Object Analysis

The Whirlpool Galaxy (Messier 51) is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici and was the first galaxy to be classified as a spiral galaxy. Its distance is estimated to be 23 million light-years.

M51 is famous for its clearly defined spiral arms, which are actually density waves that compress gas and trigger star formation. The galaxy is interacting with a smaller companion galaxy, NGC 5195, which is visibly connected to the end of one of the Whirlpool's arms. This interaction has enhanced the spiral structure.

It is one of the most popular targets for amateur astronomers. In binoculars, it appears as a fuzzy patch, but large amateur telescopes can reveal the spiral structure that Lord Rosse first sketched in 1845.