Observing this specific occasion, referred to as an occultation, was solely doable as a result of JWST can see a lot fainter stars than some other telescope, says Pablo Santos-Sanz, an astronomer on the Andalusian Institute of Astrophysics in Spain and one of many undertaking’s leaders.
“This was distinctive,” he tells Astronomy. “It allowed us to characterize these rings as by no means earlier than.”
How Chariklo acquired its rings
Like other centaurs, Chariklo is a Kuiper Belt object that was dislodged from its authentic excessive orbit on the sting of the solar system by the gravity of Neptune. Because of this, it now orbits the Solar between Saturn and Uranus.
Finally, Chariklo will possible be swallowed up by Jupiter, particularly if it will get nudged nearer to the gas giant. But when it does someway make it to the interior solar system, then it’s possible destined to behave extra like a full-fledged comet.
Astronomers found Chariklo again in 1997. Nevertheless it wasn’t till a unique star handed behind the centaur in 2013 that they observed a “double blink” shortly earlier than and after the occultation. This indicated that Chariklo hosts rings of fabric round it, a bit like a tiny saturnian system.
Measurements of the surprising dips in brightness recommended Chariklo has two rings that orbit about 155 miles (250 km) above its frozen floor.
Santos-Sanz thinks these rings are made up of tiny items of the centaur, largely water ice, which have amassed in a area with “3:1 spin-orbit resonance” — that means Chariklo rotates one time for each 3 times the fabric orbits it.
“Particles from the floor of Chariklo can escape the thing after impacts from different our bodies or meteorites,” he says. “These particles… find yourself on this particular stability area after which kind the rings.”
Planning for an occultation
To seize the brand new observations, Santos-Sanz and his colleagues made weekly predictions of Chariklo’s orbit and up to date the place of JSWT accordingly. (The space telescope carries out station-keeping maneuvers to remain on the second Lagrange point [L2], the place the Earth shades it from the Solar.)
One among Santos-Sanz colleagues is astronomer Filipe Braga Ribas of the Federal College of Know-how Paraná in Brazil, who led the observations that discovered Chariklo’s rings in 2013 utilizing ground-based telescopes in South America.
The most recent observations had been particularly troublesome, Braga Ribas tells Astronomy, as a result of JWST was usually shifting.
