The Whirlpool Galaxy, also known as Messier 51 and NGC 5194, is a grand design spiral galaxy, located 23 million light years away from Earth in the constellation Canes Venatici. It was the first galaxy that was classified as a spiral galaxy.
This planet has a companion, NGC 5195. Both galaxies may be seen with binoculars.[1]
Discovery[]
The galaxy was discovered by Charles Messier on October 13, 1773, while hunting down objects that could confuse comet hunters. He designated the object "Messier 51" in his catalogue. The companion galaxy NGC 5195 was discovered in 1781 by Pierre Méchain, but it was not known whether it was an interacting galaxy or another galaxy passing at a distance.
Overview[]
The Whirlpool Galaxy lies some 23 million light years away from Earth, and has an estimated diameter of 76,000 light years - around 43% of the Milky Way. It has an estimated mass of 160 billion solar masses, around 10.3% of the Milky Way Galaxy's mass.
At the center of the spiral, a black hole is present.
Spiral structure[]
The spiral structure of the Whirlpool Galaxy is belived to be the result of the close interaction between it and its companion galaxy NGC 5195, which may have passed through the main disk of the Whirlpool Galaxy around 500 to 600 million years ago.
Planet candidate[]
In September 2020, it was announced that a planet orbiting the high-mass X-ray binary M51-ULS-1 in the Whirlpool Galaxy was discovered. This planet was detected by eclipses of the X-ray source, which consists of a stellar remnant (either a neutron star or a black hole, and a massive star, likely a blue supergiant.
Companion[]
NGC 5195 is a dwarf galaxy that is interacting with the Whirlpool Galaxy.
Galaxy group[]
The Whirlpool Galaxy is a member of the M51 Group, and is the brightest galaxy in that group.