A global temperature map of the hot gas-giant exoplanet WASP-43 b has been created using data collected from NASA’s James Webb Space Telescope. The map, 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, shows that brighter emissions indicate 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 its unique emissions.
The observations made by the James Webb Space Telescope allowed for a detailed measurement of each side of WASP-43 b as it completed a full 19.5-hour orbit. Being tidally locked, the planet’s rotation rate matches its orbital period, causing different sides to come into view as it moves around its star.
WASP-43 b has an average daytime temperature of 2,280°F (1,250°C) and a nighttime temperature of 1,115°F (600°C). The temperature map also indicates that