KELT-20b, also known as MASCARA-2b, was an exoplanet announced in 2017.

It is an Ultra-hot Jupiter orbiting an A-type star.

The carbon monoxide, steam[1][2] and neutral iron[3] detection in the atmosphere of KELT-20b was announced in 2022.

The host star is an A-type main-sequence star in the constellation of Cygnus having 2.282 solar masses, 1.617 solar radius and an apparent magnitude of 7.58.