Distance from Earth: 615 lightyears
KELT-9b holds the record for being the hottest known gas giant discovered so far. It’s so hot in fact that the term ‘hot Jupiter’ wouldn’t do it justice – instead, it is classed as an ‘ultrahot Jupiter’. It reaches temperatures of over 4,300 degrees Celsius as it orbits its extremely hot, young blue star.
Analysis of KELT-9b’s spectral data revealed that its superheated atmosphere contains iron and titanium atoms. While these elements are common, they are usually present within other molecules. On KELT-9b it’s too hot for clouds to condense, so these metals can exist alone.