XMM-Newton's X-ray view of the Whirlpool Galaxy (M51)
The Whirlpool Galaxy, also known as M51 (or NGC 5194), is one of the most spectacular examples of a spiral galaxy. With two spiral arms curling into one another in a billowing swirl, this galaxy hosts over a hundred billion stars and is currently merging with its companion, the smaller galaxy NGC 5195.
Around 30 million light-years away, the Whirlpool Galaxy is close enough to be easily spotted even with binoculars. Using the best telescopes available both on the ground and in space, astronomers can scrutinise its population of stars in extraordinary detail.
This image shows the Whirlpool Galaxy as seen at X-ray wavelengths by ESA's XMM-Newton X-ray Observatory.
It reveals the remains of previous stellar generations, which shine brightly in X-rays. They are either the sites where massive stars exploded as supernovae in the past several thousand years, or binary systems that host neutron stars or black holes, the compact objects left behind by supernovae.