WASP-107b’s atmospheric composition deduced from JWST/MIRI Transmission Spectrum_black (IMAGE)
Caption
A transmission spectrum of the warm Neptune exoplanet WASP-107b, captured by the Low Resolution Spectrometer (LRS) of the Mid InfraRed Instrument (MIRI) on board JWST, reveals evidence for water vapour, sulfur dioxide, and silicate (sand) clouds in the planet’s atmosphere.
Astronomers start by measuring the star’s light when the exoplanet is not transiting. This is the baseline starlight. As the exoplanet begins to transit (i.e., it passes in front of its host star), it partially blocks the starlight. During this time, some of the starlight passes through the exoplanet’s atmosphere. Astronomers measure the total light (starlight plus starlight that passes through the exoplanet’s atmosphere) during transit. For each wavelength, the amount of starlight blocked by the planet and its atmosphere (white circles) is then calculated by subtracting the baseline starlight from the total light measured during transit.
The JWST MIRI transmission spectrum was obtained on 19-20 January 2023, for wavelengths between 4.61 - 11.83 micron. Data are complemented with Hubble data, taken on 5-6 June 2017, between 1.1 - 1.7 micron. The solid orange line is the best-fit model to the JWST and Hubble data. The shaded coloured regions indicate the contribution of water vapour (in red), sulfur dioxide (in blue), and sand clouds (in yellow) to the best-fit model.
Credit
Michiel Min / European MIRI EXO GTO team / ESA / NASA
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This image may only be used with appropriate credit and in relation to the press release "James Webb Space Telescope detects water vapour, sulfur dioxide and sand clouds in the atmosphere of a nearby exoplanet", issued under embargo on November 13, 2023.
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