“KELT-9 radiates so much ultraviolet radiation that it may completely evaporate the planet,” Keivan Stassun, a professor of physics and astronomy at Vanderbilt University who took part in the study published in the journal Nature, said in a statement. “Or, if gas giant planets like KELT-9b possess solid rocky cores as some theories suggest, the planet may be boiled down to a barren rock, like Mercury.”
KELT9b is tidally locked to its host star, in the same way the moon is tidally locked with Earth — one side is always facing KELT-9. Because of this, molecules like water, methane, carbon dioxide and hydrogen are unable to form.
As the star produces such intense radiation, the day side of planet’s atmosphere would be stripped down to individual atoms.
“Then as night falls, all those hydrogen atoms will try and get back together, creating an inferno at dusk,” said Thomas Beatty, a research scientist at Penn State University and a co-author on the study. “On Earth, this same process is used to create one of the hottest welding flames known.”