Spiral galaxy M51 (Whirlpool) interacting with its smaller companion NGC 5195.

M51 · galaxy

Whirlpool Galaxy

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.

RA13h 29m 56sDec+47° 13' 50"

Identity & coordinates

Identification

Primary designation: M51
All designations: M51 · NGC 5194 · Whirlpool Galaxy
Object type: Galaxy
Constellation: Canes Venatici
Best viewing: Spring

Coordinates & physical

Right ascension (J2000): 13h 29m 56s
Declination (J2000): +47° 13' 50"
Apparent magnitude (V): —
Distance: —
Redshift (z): 0.002000

III

Visibility tonight

In your gallery

April 12, 2025 · Backyard Observatory, Michigan

Whirlpool, with Companion

Two galaxies dancing around the question of whether they'll merge.

Integration

3h 18m

Subs

198 × 60s

Telescope

Celestron Origin

Camera

Sony IMX178 (built-in)

Bortle

6

Moon

Last Quarter

View full capture

The science

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. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. It is 31 million light-years away and 23.58 kiloparsecs (76,900 ly) in diameter.

Summary adapted from Wikipedia · CC-BY-SA-4.0