Rings around Quaoar found using HiPERCAM
Astronomers have found a new ring system around a dwarf planet on the edge of our Solar System, and it’s shaking up what we thought we knew about ring systems. The ring system orbits Quaoar, a dwarf planet half the size of Pluto that’s located beyond Neptune.
The team of international astronomers made the discovery using HiPERCAM, a super sensitive high-speed camera mounted on the world’s largest optical telescope, the Gran Telescopio Canarias. Instead of seeing the rings directly, they noticed a dip in light as the light from a background star was blocked by Quaoar during its orbit. To their surprise, there were two more dips in light before and after the event, revealing the presence of a ring system.
New ring system joins exclusive group of just four planets
Ring systems are rare in our Solar System, with only five known to exist – Saturn, Jupiter, Uranus, Neptune, and now Quaoar. All the previously known ring systems were close to their parent body, but Quaoar’s ring system is much further out, at over seven planetary radii. This is double the previously believed maximum radius according to the Roche limit, which is the outer limit of where ring systems can survive.
Revaluating theories on planetary ring formation
This discovery is making scientists re-evaluate their theories on ring formation. According to Professor Vik Dhillon from the University of Sheffield,
“It was unexpected to discover this new ring system in our Solar System, and it was doubly unexpected to find the rings so far out from Quaoar, challenging our previous notions of how such rings form.”
The team used HiPERCAM to make the discovery as the event only lasted a minute and the rings were too small and faint to be seen directly.
Image Credits
In-Article Image Credits
Artist impression of the dwarf planet Quaoar and its rings via University of Sheffield with usage type - Creative Commons License. ESA, CC BY-SA 3.0 IGOFeatured Image Credit
Artist impression of the dwarf planet Quaoar and its rings via University of Sheffield with usage type - Creative Commons License. ESA, CC BY-SA 3.0 IGO
