Rings around a tiny body have changed over the past decade

For decades, astronomers believed that celestial rings were exclusive to massive planets. However, in 2013, a small, dark object orbiting between Saturn and Uranus unexpectedly presented a unique case. As it passed in front of a star, astronomers observed not one, but two distinct rings encircling a body just 250 kilometers in diameter.

This discovery intrigued Pablo Santos-Sanz, an astronomer at the Instituto de Astrofísica de Andalucía in Granada, Spain. Since then, the focus has shifted towards understanding the composition of these rings and their longevity. A recent study led by Santos-Sanz utilized the James Webb Space Telescope to observe the same object, now identified as Chariklo, during another star passage.

The results revealed significant changes in the rings' structure over the past decade. One ring had thickened while the other had almost disappeared. The reasons behind these transformations remain unclear. The technique used to make this observation is straightforward. Astronomers predict when a Solar System object will pass in front of a star, and the resulting dimming of starlight reveals the object's size, shape, and surroundings.

However, this method becomes increasingly complex for minor bodies, especially those located far from our solar system.