Astronomers say they have discovered a planet with a gigantic ring system that is 200 times larger than that around Saturn.
It is the first such structure detected around a planet beyond our Solar System.
The researchers say there are probably more than 30 rings, each measuring tens of millions of kilometres in diameter.
The findings by a Dutch-US team are to be published in the Astrophysical Journal.
Gaps detected in the ring system also suggest that some of the material may already have coalesced to form moons. This phenomenon can be seen at work in Saturn’s rings today.
“You could think of it as kind of a super Saturn,” said Prof Eric Mamajek, from the University of Rochester in the US.
The rings were found in data gathered by the SuperWASP observatory, which can detect exoplanets as they cross in front of their parent stars, causing the light from them to dim.
In this case, the astronomers saw a complex series of deep eclipses lasting for 56 days. They think this is caused by a planet with a giant ring system blocking out light as it passes in front of the star J1407.
“The light curve from end-to-end took about two months, but we could see very rapid changes in the space of one night,” co-author Dr Matthew Kenworthy, from the University of Leiden, the Netherlands, told BBC News.
“Over a time of half an hour, the star can dim by 30 or 40%.”
If Saturn’s rings were the same size as those around J1407b, they would be easily visible from Earth at night and would be many times larger than a full Moon.