The CHEOPS telescope operated by the European Space Agency often searches for planets outside of our solar system, but lately, it made an intriguing discovery that was closer to home: a sizable ring surrounding the minor planet Quaoar.
The dwarf planet Quaoar, which is situated in the Kuiper belt about 44 times further from the sun than Earth is, was the site of the ring’s discovery. The planet is only 690 miles across, but the ring that surrounds it has a radius that is seven and a half times that.
Photo Credit: Astronomy Magazine
Even with a powerful space-based telescope like CHEOPS, the planet is difficult to observe due to its small size and great distance from the sun. Researchers had to wait for occultations, in which a background star passes in front of another star and blocks out its light, in order to view the dwarf planet. But these occurrences are uncommon and unpredictable.
One of the CHEOPS researchers, Isabella Pagano, stated in a statement, “I was a little doubtful about the feasibility to do this with CHEOPS.” But we looked at the viability.
The crew was highly happy with the outcomes after several failed attempts to see an occultation. The Cheops data had incredible signal-to-noise ratios, according to Pagano.
They were able to see the dwarf planet and its ring thanks to these findings. “When we combined all of the information, we noticed brightness drops that weren’t due to Quaoar but indicated the presence of material in a circular orbit around it. Lead researcher Bruno Morgado remarked, “As soon as we noticed that, we said, “Okay, we are seeing a ring around Quaoar.
But there’s something odd about this ring. Astronomers would anticipate that the material in the ring would also consolidate into a moon since Quaoar has a small moon called Weywot. Once it crosses a point known as the Roche limit, the material is forced apart by gravity and forms a ring as it approaches a large body like a planet. However, Quaoar’s ring goes far beyond the Roche limit.
Photo Credit: New Scientist
The team is perplexed by this discovery and hypothesizes that it may be because Quaoar’s extremely low temperatures prevent the ring’s particles from fusing together to form a moon. But for now, it’s unclear what exactly caused it.