Whirlpool Galaxy (M51)
Galaxy · Interacting spiral
The Whirlpool Galaxy is a classic spiral seen face-on, tugged by a smaller companion galaxy. Their gravitational dance has sharpened its spiral arms and triggered the birth of many new stars.
- 30 million light-years awayEven light – the fastest thing there is – needs 30 million years to get here.
- NGC 5195Partner
- Canes VenaticiConstellation
Take a closer look
Painted Spiral Arms
Each arm of the Whirlpool is threaded with dark lanes of dust, sprinkled with blue clusters of young stars and dotted with pink clouds of glowing hydrogen. The pink patches are nurseries, lit up by newborn stars switching on inside them.
A View With a Neighbour
From a planet inside the Whirlpool, the companion galaxy NGC 5195 would hang in the sky as a large hazy glow. The nearby spiral arm would be crowded with bright young stars and glowing clouds, much busier than the night sky we see from Earth.
Supernova Hotspot
Astronomers have spotted three supernovae – exploding stars – in the Whirlpool since 1994, and amateur astronomers helped discover some of them. Catching stars in the act of dying lets scientists check what kinds of stars blow up and how.
How we found out
- 1773
Charles Messier discovers it.
- 1845
Lord Rosse, using a giant telescope in Ireland called the “Leviathan”, sees and draws its spiral arms – the first time a spiral structure was recognised.
- 2005
Hubble releases one of its most famous images of the galaxy.
Why do galaxies have spiral arms?
The arms are like traffic jams of stars and gas: regions where material piles up as it orbits, causing bursts of new, bright blue stars.
See it yourself
A small telescope from a dark site, below the handle of the Big Dipper.
From the encyclopedia
Read the full article on Wikipedia ↗Got it?
Mark Whirlpool Galaxy (M51) as explored to earn 10 XP.