This Planet Burns Hotter Than Most Stars

The phrase “hot mess” has never been more appropriate. Astronomers have found a massive, wildly whirling, disintegrating exoplanet that reaches a burning 7800°F. The team described the bizarre gas giant in the journal Nature.

The Hubble and other big space telescopes tend to get all the glory, but smaller instruments here on Earth are working just as hard. The newly discovered exoplanet, called KELT-9b, was named for the humble scope that spotted it—a KELT, or Kilodegree Extremely Little Telescope.

Located 650 light-years away in the constellation Cygnus (pictured here), KELT-9b is one strange celestial body.

With nearly three times the mass of Jupiter, it's gargantuan, and it’s locked in breakneck orbit around the star HD 195689 (a.k.a. KELT-9). The exoplanet is so close to the star and moving so fast that one full transit around HD 195689—what we think of as a year—takes less than two days.

The planet is also tidally locked to its star, the same way we only ever see one side of our Moon. And the side of KELT-9b that faces HD 195689 is on permanent, hellish blast. It’s so hot that if you somehow managed to get water onto its surface, the water would immediately dissociate into its component molecules of hydrogen and oxygen.

Co-lead author Scott Gaudi of The Ohio State University says he and his colleagues are just boggled by the discovery.

"It's a planet by any of the typical definitions based on mass, but its atmosphere is almost certainly unlike any other planet we've ever seen just because of the temperature of its day side," he said in a statement.

But KELT-9b’s blazing, wild ride is not destined to last. The paper authors say the exoplanet is likely already shedding mass like a comet as it moves. And if this gradual melting doesn’t destroy it, its ravenous sun will swallow the peculiar, scalding planet like a cookie straight out of the oven.

"The long-term prospects for life, or real estate for that matter, on KELT-9b are not looking good,” co-lead author Keivan Stassun of Vanderbilt University said in the statement.

This is too bad for KELT-9b, but it could be very good for science.

"As we seek to develop a complete picture of the variety of other worlds out there,” Stassun said, “it's important to know not only how planets form and evolve, but also when and under what conditions they are destroyed."

Gaudi says the discovery is a reminder that we still have a lot to learn, and that we need to think bigger.

“Mother Nature is way more imaginative than we are,” he told CNN. “And anytime you find something this weird, it broadens your horizons of what nature can possibly be like."