Astronomers using the NASA / ESA / CSA James Webb space telescope detected silicate clouds in the atmosphere of the YESS-1 exoplanet and a circumstary disc around its brother planet, YSES-1B.
An artist’s interpretation of the Yeses-1 system composed of the star of the sun in the center, Yses-1B and its dusty circumstances (right) and Yses-1 with silicate clouds in its atmosphere (on the left). Image credit: Ellis Bogat.
YSES-1 is a solar type star located about 309 light years in the Musca constellation.
Also known as TYC 8998-760-1 or 2MASS J13251211-6456207, the star is roughly the same mass as our sun, but has only 16.7 million years.
He hosts two planets, Yeses-1b and Yeses-1c, at least 14 and 6 times more massive than Jupiter.
They orbit their parent star at distances of 160 and 320 at; This places the extraterrestrial worlds much further from their star than Jupiter or Saturn are in the sun.
The YSES-1B and C are redest than the other exoplanets (or brown dwarfs), which suggests that they can have distinct atmospheric properties.
The system has been observed with several webb front telescopes; However, detailed observations of this system were not possible before the webb program.
“Exoplanets directly imagined are the only exoplanets that we can really take photos,” said Dr. Evert Nasedkin, a postdoctoral researcher at Trinity College Dublin.
“These exoplanets are generally still young enough for them to be hot of their formation and it is this warmth, seen in the thermal infrared, that we, as astronomers, observe.”
Using webb spectroscopic instruments, Dr. Nasedkin and his colleagues have obtained large spectra of YES-1B and YSES-1 planets.
These include the first direct observations of the silicate clouds in the atmosphere of Yses-1, confirming the previous theories on the composition of its atmosphere.
These clouds of silicate are likely to contain iron, which can rain on the planet.
Astronomers estimate that cloud particles are 0.1 μm or more.
“When we looked at the smallest more distant companion, known as Yses 1-C, we found the revealing signature of the silicate clouds in the infrared world,” said Dr. Nasedkin.
“Essentially made of sand particles, this is the strongest silicate absorption characteristic observed in an exoplanet to date.”
“We believe that this is linked to the relative youth of the planets: the young planets are slightly more important in the radius, and this prolonged atmosphere can allow the cloud to further absorb the light emitted by the planet.”
“Using detailed modeling, we were able to identify the chemical composition of these clouds, as well as details on the shapes and sizes of cloud particles.”
The authors also detected a silicate disk around YSES -1B – a rare observation for exoplanets substrate companions.
This observation indicates that YSES-1B can be a relatively newly formed planet.
The results offer new perspectives on the first phases of exoplanet formation and the evolution of the atmosphere.
“The planets of the YSES-1 system are also too largely separated to be explained through the theories of current formation, so that the additional discoveries of distinct silicate clouds around YESS-1C and small hot dusty materials around YESS-1B lead to more mysteries and complexities to determine how the planets are formed and evolved”, Hoch, an astronomer of space for the telescope science science institute Institute of the Sciences of Telescopes.
The team’s results appear this week in the newspaper Nature.
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KKW HOCH and al. Silicate clouds and circumstories disc in the YESS-1 exoplanet system. Naturepublished online on June 10, 2025; DOI: 10.1038 / S41586-025-09174-W
