As of 2020, which exoplanet is the hottest?

KELT-9b is the hottest gas giant exoplanet known, with a dayside temperature of between 4,050 and 4,600 K (surface temperature tops 3780 degrees Celsius), which makes it hotter than M-type stars and some K-type stars as well. KELT-9b was detected using the Kilodegree Extremely Little Telescope and the results of its unusual nature were published in 2017. The atmosphere of the planet is so hot that refractory elements that would usually be sequestered into molecules can exist as atomic species. KELT-9b has surprised astronomers yet again with the discovery that its atmosphere contains the metals iron and titanium.