Ultra-Hot Jupiter-Sized Exoplanet Illustration

This is an artist's illustration of the planet KELT-20b which orbits a blue-white star. The giant planet is so close to its star (5 million miles) the torrent of ultraviolet radiation from the star heats the planet's atmosphere to over 3,000 degrees Fahrenheit. This creates a thermal layer where the atmosphere increases in temperature with altitude. This is the best evidence to date – gleaned from the Hubble Space Telescope – for a host star affecting a planet's atmosphere directly. The seething planet is 456 light-years away.