NASA’s James Webb Space Telescope has been used to create a global temperature map of the hot gas-giant exoplanet WASP-43 b. The map is based on the brightness of mid-infrared light detected from the planet in the 5- to 12-micron range by the Mid-Infrared Instrument (MIRI) on the telescope. This type of light is emitted by hot objects, with brighter emissions indicating higher temperatures.
Despite being too close to its star to be visible on its own, the brightness of WASP-43 b can be determined by measuring the total brightness of the star-planet system and subtracting the amount of light coming directly from the star. This subtraction is done by observing the system when the planet is behind the star, revealing the planet’s unique emissions.
WASP-43 b orbits its star every 19.5 hours and being tidally locked, its rotation rate matches its orbital period, causing different sides to come into view as it moves around its star. The observations made by NASA’s James Webb Space Telescope allowed for