For the first time, JWST has given us a detailed analysis of the interior of a world outside our solar system, the exoplanet WASP-107b. The extremely strange exoplanet has an atmosphere with surprisingly low levels of methane, suggesting that its interior must be significantly hotter than we thought – and core more massive too. This ultimately helps explain its cotton candy-like density.
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Previously, WASP-107b was thought to have a fairly small core, surrounded by a huge, inflated envelope of hydrogen and helium – which would require some changes to our understanding of how planets. The new JWST results mean that the exoplanet can be explained by existing models, without the need for a radical revision.
Even when WASP-107b's discovery was announced in 2017, we knew there was something strange about the exoplanet. By carefully studying how the exoplanet affected star , astronomers were able to deduce its mass and radius, which revealed that it had an incredibly low density.
Further analysis revealed that the density is so low that the world can be classified as "superfluffy" – just 0.13 grams per cubic centimeter. The average density of Jupiter, by comparison, is 1.33 grams per cubic centimeter and Earth is 5.51 grams.
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So two teams of astronomers, one led by Sing and the other led by Luis Welbanks of ASU, enlisted the JWST to take a look at the exoplanet's atmosphere.
As WASP-107b passes between us and its host star, some of the starlight is absorbed or amplified by molecules in the exoplanet's atmosphere. By studying the difference in starlight with and without the exoplanet and looking for brighter and dimmer wavelengths in the spectrum, astronomers can identify the fingerprints of specific molecules in an exoplanet's gas layer.
Although it is surprising that WASP-107b's atmosphere contains very little methane, this offers an explanation for how the exoplanet became the way it is.
See also: This exoplanet has shimmering metallic clouds
The two papers have been published in Nature. You can find them here and here.
Source: sciencealert
