The asteroide Cariclo o Chariklo is the one celestial body smaller with two rings that is known The James Webb Telescope has taken advantage of a unique opportunity, a stellar occultationto study it.
Until a few years ago it was believed that only planets and other large celestial bodies could have their own rings. But in 1997, astronomer James V. Scotti made an astonishing discovery: he found an asteroid just 250 kilometers in diameterwhich they called Cariclo (10199)who owned two rings 3 and 7 kilometers wide.
Cariclo, also called Chariklo in the original name, takes the name of a nymph, daughter of Apollo in Greek mythology. She is part of a asteoid group called centaurswhich are located between the orbits of Saturn and Uranusto some 2,400 million kilometers from the Sun.
It is an immense distance, and besides, an asteroid does not emit light like a star. So… how did they find out?
The stellar occultation of Cariclo, the asteroid with two rings
The astronomer James V. Scotti took advantage of what is called a stellar occultation. When a star passes behind a celestial object, some of the light is blocked by that object. By measuring data such as the intensity of light and the duration of the variation, secrets such as the type of celestial object what is it, or its size.
That’s how it was found to be a asteroid of 250 kilometers in diameter con two rings. Big enough to destroy the Earth if it collided with it, by the way…
The stellar occultation of Cariclo It only happens once every few years, because the orbits of the asteroid and the star it passes behind, relative to Earth, only coincide at certain times.
Coincidentally, a new occultation was to take place last October 22so astronomers took the opportunity to study Chariclo with the imposing telescope James Webb (JWST). This is a study led by the Spanish astronomer Pablo Santos-Sanz, from the Institute of Astrophysics of Andalusia, in Granada.
In the image we can see the path of the star behind the rings of the asteroidand how the light is blocked when colliding with the rings (at the bottom).
The data from this study have been published this week on the official website of the Webb telescope. From the shapes of the concealment light curves of the rings, it has been certified the thickness of the ringsthe sizes and colors of the ring particles and much more.
The JWST also observed the asteroid directly, and has verified that it contains crystalline water ice. This suggests that the asteroid could be experiencing small collisions, which trigger crystallization processes.
The James Webb Telescope has explored the asteroide Cariclothe smallest celestial body with two ringsthanks to a stellar occultation. It is an event that occurs every certain number of years, and for this reason astronomers have not wanted to miss the opportunity to study it with the most powerful telescope that exists.
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