The Whirlpool Galaxy, also
known as Messier 51a, M51a,
or NGC 5194,
is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus in the constellation Canes Venatici.
In the Catalogue of Named Galaxies, it is called Typhon Canum Venaticorum, after the Greek god Typhon.
It was the first galaxy to be classified as a spiral galaxy.
Recently it was estimated to be 23 ± 4 million light-years from the Milky Way, but different methods yield distances between 15 and 35 million light-years.
Messier 51 is one of the best known galaxies in the sky.
2017. 05. 28. 20-23 UT
60 x 60 s light
SW NEQ-5 goto
0.9x coma corrector
Stacked and processed in: PixInsight, Adobe PS, LR.