The Whirlpool Galaxy (M51) - A Grand-Design Spiral Galaxy in Canes Venatici

Basic Information

• Name: Whirlpool Galaxy (Messier 51, M51, NGC 5194).
• Type: Grand-Design Spiral Galaxy with a Seyfert 2 active galactic nucleus.
• Location: Constellation Canes Venatici.
• Distance from Earth: Approximately 23–31 million light-years.
• Size: About 60,000 light-years in diameter.
• Companion Galaxy: Interacting with NGC 5195, a smaller galaxy.
• Original Observation: 25th January 2024

Physical Characteristics

• The Whirlpool Galaxy is a grand-design spiral galaxy, meaning its spiral arms are prominent, well-defined, and symmetrical.
• Its spiral arms are star-forming regions, where massive and luminous stars are born from dense clouds of gas and dust.
• The galaxy's interaction with its companion, NGC 5195, has influenced its structure, enhancing the spiral arms and triggering star formation.
• The galaxy's nucleus is classified as Seyfert 2, indicating an active galactic nucleus with moderate activity.

Discovery and History

• The Whirlpool Galaxy was discovered by Charles Messier in 1773 and cataloged as Messier 51.
• It was the first galaxy to be classified as a spiral galaxy, thanks to observations by Lord Rosse in the mid-19th century using his large telescope, the Leviathan of Parsonstown.
• The galaxy has been extensively studied due to its proximity and striking appearance, making it a favorite target for both professional and amateur astronomers.

Observational Highlights

• Visibility: Best observed during the spring months in the Northern Hemisphere.
• Best Observing Tools: A small telescope can reveal the galaxy's core and companion, while larger telescopes or astrophotography can capture its spiral structure.
• Nearby Objects: The Whirlpool Galaxy is part of the M51 Group, a small group of galaxies in Canes Venatici.

Interesting Facts

1. Interacting Pair: The Whirlpool Galaxy and its companion, NGC 5195, are gravitationally interacting, which has shaped the Whirlpool's spiral arms and triggered bursts of star formation.
2. Photogenic Galaxy: M51 is one of the most photographed galaxies due to its symmetrical spiral arms and proximity to Earth.
3. Star Formation: The galaxy's spiral arms are "star factories," producing massive, young stars that illuminate the arms.

Original image captured by Vaonis Vespera II.

How to Locate the Whirlpool Galaxy

1. Find Canes Venatici: The constellation lies near Ursa Major. Use the handle of the Big Dipper as a guide.
2. Use a Star Map: The Whirlpool Galaxy is located near the star Alkaid, the end star of the Big Dipper's handle.
3. Enhance Visibility: Observing from a dark-sky location with a telescope or binoculars will help reveal the galaxy and its companion.

Personal Note

It took a while to upload this particular capture. The interesting fact about the Whirlpool galaxy is that, the bright cosmic structure seen right next to it, is another galaxy titled NGC 5195. In the vast cosmos, the NGC 5195 has been pulled close to the Whirlpool galaxy and is gravitationally interacting with it, much like making it a dual galaxy system. The pull from NGC 5195 has caused the arms of the Whirlpool galaxy to be stretched, as seen in the image. Current research shows that the NGC 5195 is passing behind the Whirlpool galaxy, which may become abundant to humans in a few hundreds of thousands of years. Perhaps that will give the future humans a good idea on what will happen when our Milky Way galaxy will collide with the Andromeda galaxy.