Scientists have discovered the hottest known planet located 650 light years from Earth, which is warmer than most stars in the universe and sports a giant, glowing gas tail like a comet.<br/><br/>Scott Gaudi, professor at the Ohio State University in the US and lead author of the study published in a journal said it is a planet by any of the typical definitions based on mass, but its atmosphere is almost certainly unlike any other planet ever seen just because of the temperature of its day side. <br/><br/>Researchers said, with a day-side temperature peaking at 4,326 degree Celsius the newly discovered exoplanet, designated KELT-9b, is hotter than most stars and only 926 degree Celsius cooler than Sun. <br/><br/>They said the Jupiter-like planet orbits a massive star KELT-9 every day and a half.<br/><br/>The ultraviolet radiation from the star it orbits is so brutal that the planet may be evaporating away under the intense glare, producing a glowing gas tail. <br/><br/>The reason the exoplanet is so hot is because the star it orbits is more than twice as large and nearly twice as hot as Sun said Researchers.