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JWST Reveals Dynamic Changes in Chariklo's Rings
Confirmed
In Short: Researchers using the James Webb Space Telescope (JWST) have observed dynamic changes in the ring system of Chariklo, a Centaur object in our solar system.
Researchers using the James Webb Space Telescope (JWST) have observed dynamic changes in the ring system of Chariklo, a Centaur object in our solar system.
Chariklo, discovered in 1997, is notable for its ring system, which was first observed in 2013. The latest observations, published in Science Advances, show that the two rings around Chariklo are gaining and losing material over time.
The team used a technique called stellar occultation, which involves observing the object as it passes in front of a star, to study the rings. This method was employed in 2017 and again in 2022 with the help of JWST.
The 2017 observations established a baseline for the rings' composition and sizes, while the 2022 observations with JWST revealed changes in the rings that were opposite to those observed in 2017.
Lead researcher Pablo Santos-Sanz noted that these findings suggest Chariklo's ring system is influenced by a broader range of processes than previously understood, challenging current theories on ring formation and evolution.
The observations required precise knowledge of Chariklo's orbit, the position of the star, and the trajectory of JWST, highlighting the telescope's capabilities.
Chariklo, with a radius of 125 kilometers, has its inner ring (C1R) and outer ring (C2R) orbiting about 265 kilometers and 280 kilometers from its surface, respectively.
What this adds
The study marks a new milestone for JWST as the first stellar occultation predicted, planned, and successfully observed using the telescope.
The observations were conducted on October 18, 2022, when Chariklo's orbit provided optimal conditions for observing the rings at a relative speed of around 2.5 kilometers per second.
What's confirmed
- Researchers using the James Webb Space Telescope (JWST) have observed dynamic changes in the ring system of Chariklo, a Centaur object in our solar system.
- Chariklo, discovered in 1997, is notable for its ring system, which was first observed in 2013. The latest observations, published in Science Advances, show that the two rings around Chariklo are gaining and losing material over time.
- The team used a technique called stellar occultation, which involves observing the object as it passes in front of a star, to study the rings. This method was employed in 2017 and again in 2022 with the help of JWST.
- The 2017 observations established a baseline for the rings' composition and sizes, while the 2022 observations with JWST revealed changes in the rings that were opposite to those observed in 2017.
- Lead researcher Pablo Santos-Sanz noted that these findings suggest Chariklo's ring system is influenced by a broader range of processes than previously understood, challenging current theories on ring formation and evolution.
- The observations required precise knowledge of Chariklo's orbit, the position of the star, and the trajectory of JWST, highlighting the telescope's capabilities.
- Chariklo, with a radius of 125 kilometers, has its inner ring (C1R) and outer ring (C2R) orbiting about 265 kilometers and 280 kilometers from its surface, respectively.
What's still developing
- “Achieving this required knowing with extraordinary precision the orbit of Chariklo, the position of the star—thanks to ESA’s Gaia mission—and the trajectory of JWST,” said study co-author Yücel Kilic, a postdoctoral researcher at the IAA-CSIC, noting the telescope’s position approximately 1.5 million kilometers from Earth at the L2 Lagrange point, close to where NASA’s newly-launched Nancy Grace Roman Space Telescope is not also positioned in orbit.
- While many questions remain, such as what specifically drives the changes observed in the Chariklo’s rings, the team’s “force us to rethink how [rings] form, how they evolve, and what mechanisms maintain their stability,” Santos-Sanz said of the team’s observations.
- The unusual object, formally known as 10199 Chariklo, is a class of small celestial objects astronomers call centaurs, whose orbit around the Sun falls between Jupiter and Neptune, and which cross the orbits of at least one of our Solar System’s giant planets.
- Originally discovered in 1997, additional observations of Chariklo in 2013 during a stellar occultation event revealed a pair of dense rings encircling the minor planet—an unexpected discovery that identified it as the second smallest object known to possess such a feature; another centaur, Chiron, remains the smallest similar ringed object.