Whirlpool Galaxy Facts

The Whirlpool Galaxy was the first galaxy to receive an official label designation for its spiral design.

Whirlpool Galaxy Profile

Constellation:Canes Venatici
Also known as:Messier 51a, M51a, and NGC 5194
Type:Spiral Galaxy
Diameter:60,000 light years
Distance:23 Million light years
Mass:160 billion M☉
Number of Stars:100 billion

The Whirlpool Galaxy is considered to be a classic structure and shape for what many people think of as a spiral galaxy, and it is fairly close to our Milky Way Galaxy.

Researchers have focused on the Whirlpool Galaxy for study mainly because of its relationship with a dwarf galaxy that is close to it. Other scientific designations for the Whirlpool Galaxy include: M51, M51A, and NGC 5194.

Who discovered the Whirlpool Galaxy

In 1773, astronomer Charles Messier was looking for objects as he charted the night skies. He was the first to discover the Whirlpool Galaxy during this research.

However, this was a general discovery. It wasn’t until an Irish astronomer, William Parsons, discovered the galaxy’s spiral nature and the remnants of its neighboring dwarf galaxy as he worked at Birr Castle.

Thus far, the Whirlpool Galaxy is one of the most famous. It is part of the Hunting Dogs (Canes Venatici) Constellation and when you see it through a good telescope, there is clear visibility of its side.

Easy to see

It is very bright in the night sky and can be easily seen with the naked eye, binoculars, or telescopes.

Both the Whirlpool Galaxy and its dwarf galaxy neighbor are colliding and merging.

This is a major reason for study as scientists are watching to see that the dwarf galaxy original shape has already been lost and both of the Whirlpool Galaxy spiral arms have become misshapen.

Due to the dwarf galaxy supplying huge amounts of raw materials, the merger has created a burst of star production activity in the galaxy’s center. Currently, the two galaxies are connected with a gas and dust bridge.

Facts about the Whirlpool Galaxy

  • The companion dwarf galaxy has been given an official scientific designation of M51b. However, since it’s believed that it will eventually be merged into M51 (Messier 51), it hasn’t been named for the individual that discovered it.
  • Like many galaxies, the Whirlpool Galaxy has a supermassive black hole at its center. The black hole is surrounded by dust rings that are forming new stars on a consistent basis. This activity is at such a pace that astronomers have classified the Whirlpool Galaxy as a Seyfert Galaxy.
  • Those that specialize in taking exceptional images of the constellations are known for their astrophotography. The Whirlpool Galaxy is one of the most popular galaxies for these pictures as the details can be blown up when they use professional-grade telescopes and time-lapse exposures. Some of the most well-known images of the Whirlpool Galaxy are those that were taken in 2005 by the Hubble Space Telescope.
  • Scientists continue to debate exactly how close the Whirlpool Galaxy is to the Earth.
  • As we develop more sophisticated methods of observation, researchers hope to narrow down the proximity of the Whirlpool Galaxy to our own. They currently think it is 23 million light-years away.
  • Although the Whirlpool Galaxy was discovered in 1773, it took until 1845 for it to be given the spiral galaxy designation.
  • The 3rd Earl of Rosse, William Parsons, was incredibly wealthy and used his money to buy the largest telescope in the world (at that time) to view the Whirlpool Galaxy and indicate its spiral shape.
  • Astronomers have estimated that there are over 100 billion stars in the Whirlpool Galaxy.
  • The total mass of the Whirlpool Galaxy is around 160 billion times the mass of our Sun.
  • NASA has indicated that the diameter of the Whirlpool Galaxy is exactly 60,000 light-years across.
  • More recently, astronomers have noted that there has been a drastic increase in supernova explosions in the Whirlpool Galaxy, and they are unsure for the reason.


  • What important fact made the Whirlpool Galaxy so well-known?
    it was the first galaxy to be identified as a spiral galaxy
  • What important thing is happening to the Whirlpool Galaxy that makes it the most studied?
    It is colliding/merging with its dwarf galaxy
  • What is the estimate distance between the Whirlpool Galaxy and the Earth?
    23 million light-years
  • When you look at both the Whirlpool Galaxy and its dwarf galaxy, what is the first thing you notice?
    both galaxies are misshapen due to their merging/collision
  • What is a scientific designation for the Whirlpool Galaxy?
    M51, M51A, and NGC 5194
  • Has the dwarf galaxy been given a scientific designation?