James Webb Space Telescope observes changes in Chariklo's rings over a decade

Chariklo's Rings Show Dynamic Changes

Astronomers previously believed rings were exclusive to giant planets until 2013, when the minor planet Chariklo, located between Saturn and Uranus, was observed with two narrow rings. Recent observations using the James Webb Space Telescope (JWST) have shown that these rings are not static.

A study led by Pablo Santos-Sanz utilized the JWST to observe Chariklo as it passed in front of a background star. This event, known as an occultation, allowed researchers to analyze the rings' current state.

Significant Alterations in Ring Structure

The JWST observations revealed notable changes in Chariklo's ring system over the past decade. One of the two rings has increased in density, while the other has almost entirely vanished. The exact reasons for these changes are currently unknown.

In 2013, ground telescopes identified two rings, C1R and C2R, orbiting Chariklo at distances of 390 and 405 kilometers from its center. These rings were only a few kilometers wide and separated by approximately 7 kilometers.

Occultation Technique for Observation

The observational technique relies on predicting when a Solar System object will pass in front of a star. As the object and its rings block the starlight, the dimming pattern reveals details about its size, shape, and surrounding structures. This method is particularly challenging for small, distant bodies due to their minuscule silhouettes and the need for precise positional data.

The recent JWST observations confirm that rings around minor bodies are dynamic systems, capable of significant evolution over relatively short timescales, challenging previous assumptions about their stability.