When galaxies collide, the results aren't always disastrous. Many collisions could really be called close encounters, with the stars in each system easily passing by one another. Sometimes the collisions result in beautiful new formations, as in the image above.
The "bulls-eye" formation, with one galaxy forming a complete ring around another, is rare — and this is by far the closest one ever spotted. At a distance of 30 million light years, it's seven times closer than the next one. Dense star cover in front of it and lots of light interference from a particularly bright nearby star have kept it hidden from sight until now.
“Not only is this system visually stunning, but it’s close enough to be an ideal target for detailed study," Quentin Parker of the University of Hong Kong, who led the discovery team along with Albert Zijlstra of the University of Manchester, said in a statement.
"The ring is also quite low in mass — a few thousand million Suns, or less than 1% of the Milky Way — so our discovery shows that collision rings can form around much smaller galaxies than we thought," Parker said.
Because galaxies of this size are much more common than large ones, the researchers say, this discovery could indicate that such collisions are up to 10 times more frequent than previously assumed.
The formation, which was described recently in the Monthly Notices of the Royal Astronomical Society, has been dubbed "Kathryn's Wheel," in homage to both the brilliant pinwheel fireworks that the ring represents and to Zijlstra's wife, Kate.