K2-138b is a potentially rocky Super-Earth exoplanet orbiting every 2 days around a K1V star.
The planet, along with the four others in the system, was found by citizen scientists of the Exoplanet Explorers project on Zooniverse.
At this proximity, the planet is likely very hot and receives 486 times the stellar flux as Earth.
The planet has likely a rocky core and a substantial atmospheric layer, composed of volatiles.
[4][5][6] The K2-138 system, including K2-138b will be studied with CHEOPS to further constrain the mass of the planets with transit-timing variation (TTV).