Messier 51a
The Whirlpool Galaxy is also known as M51a or NGC 5194.
It is an interacting grand-design galaxy and the first to be classified as a spiral galaxy.
The Dwarf galaxy NGC 5195 is gravitationally interacting with the whirlpool , it is pulling on its spiral arm as it passes behind the galaxy.
The Whirlpool Galaxy is about 31 million light years away from Earth it can be found in the Constellation Canes Venatici.