The Whirlpool Galaxy, also known as Messier 51a or NGC 5194, 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. It is 7.22 megaparsecs away and 23.58 kiloparsecs in diameter.
With an apparent magnitude of 8, the Sombrero galaxy is beyond the limit of naked-eye visibility but can be spotted through small telescopes most easily during May. M104 is located 28 million light-years away in the constellation Virgo, and with a mass equal to 800 billion suns, it is one of the most massive objects in the Virgo galaxy cluster.