Astronomers have discovered a new ring galaxy which arose from a galactic collision, 30 million light years away from Earth.
The galaxy was found by chance by astronomers led by Professor Quentin Parker at the University of Hong Kong (HKU) and Professor Albert Zijlstra at the University of Manchester, during a special wide-field survey of the Southern Milky Way.
The ring is 30 million light years away and is called “Kathryn’s wheel”, named after the famous fireworks that it resembles and Zijlstra’s wife Kathryn.
Shock-waves from the collision compress reservoirs of gas in each galaxy and trigger the formation of new stars, researchers said.
This creates a spectacular ring of intense emission, and lights up the system like a Catherine wheel on bonfire night.
Galaxies grow through collisions but it is rare to catch one in the process, and extremely rare to see a bull’s-eye collision in progress, Xinhua news agency reported.
The basic discovery happened some years ago and the follow-up analysis and interpretation are fundamental to all science, Parker said.
“Before you announce a lovely discovery you have to spend a lot of time doing careful follow-up observations to confirm the discovery,” said Parker.
The newly discovered ring galaxy is seven times closer than anything found before, and forty times closer than the most famous example of collisional ring galaxies, the ‘Cartwheel’ galaxy, researchers said.
Kathryn’s Wheel is located behind a dense star field and close to a very bright foreground star, which is why it had not been noted before.
There are very few other galaxies in its neighbourhood: the odds of a collision in such an empty region of space are low.
The study was published in the journal Monthly Notices of the Royal Astronomical Society.