Live: Amazon Event Wednesday Probe Crashes Into Asteroid Prime Day 2: Oct. 11-12 Tesla AI Day Hurricane Ian Satellite Images Save on iPad Pro Refurbs Apple Watch Ultra Review EarthLink Internet Review
Want CNET to notify you of price drops and the latest stories?
No, thank you

'Hot Jupiter' heats up fast as it passes close enough to high-five its star

Scientists have spotted a distant gas-giant planet that goes through wild temperature swings as it passes its star on a highly eccentric orbit every 111 days.

A simulation of the turbulent atmosphere of HD 80606b.

Since scientists started identifying lots of planets orbiting distant stars in the past decade, one of the weirder types is the surprisingly common "hot Jupiter" -- a gas giant like the ones we know that orbits very close to its star. Now NASA's Spitzer space telescope has spotted a particularly weird hot Jupiter that's more of a "very hot and cold Jupiter."

The planet, called HD 80606b, is about 190 light-years from Earth and has a highly eccentric orbit around its star that's more like that of a comet than the planets in our solar system. Every 111 days, the planet passes so close around its star that it almost touches it -- if it were able, it could probably reach out and high-five or fist-bump its sun. It then swings farther away from its star (a little less than the distance between our sun and Earth) before doing a U-turn at the other end of its elliptical orbit to repeat the cycle.

In our own solar system, comets are thought to make similar trips around the sun, though at much longer intervals. Many comets eventually break up under the intense heat from our sun in these close passes during their eccentric orbits.

But HD 80606b is too large to suffer such a fate. Instead, the gas giant planet regularly experiences what must be one of the more insane examples of regular climate change in the universe.

During its close approach of its sun, the side of the planet facing the star is thought to heat up very quickly, to temperatures of more than 2,000 degrees Fahrenheit (1,100 degrees Celsius). The temperatures on the planet could heat up by 1,500 degrees and then cool by that same amount in the span of a single day.

"As the planet gets closer to the star, it feels a burst of starlight, or radiation. The atmosphere becomes a cauldron of chemical reactions, and the winds ramp up far beyond hurricane force," Greg Laughlin, an astronomer at the University of California at Santa Cruz, said in a news release from NASA on Monday. He's co-author of a new study on hot-Jupiter formation that will appear in The Astrophysical Journal Letters.

The researchers think the planet may be in the process of migrating inward in its solar system and that it could eventually see its orbit "flatten out" to something more similar to the gas giants in our own neighborhood.

Check out the NASA simulation below to get a better idea of what the planet's bizarre orbit looks like.