Astronomers spot planet with boiling atmosphere (+video)
A planet roughly the size of Jupiter is spewing a huge plume of gas, an eruption caused by activity on its parent star.
A Jupiter-size planet around a distant star has given astronomers a rare glimpse into the effects of space weather beyond our solar system: a view of an alien world unleashing an intense plume of gas triggered by an eruption from its parent star.Skip to next paragraph
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Credit: NASA / ESA / Hubble
A team of astronomers used the Hubble Space Telescope to study the exoplanet HD 189733b, and noticed curious changes in the planet's upper atmosphere after it was bombarded with intense X-ray radiation from a flare unleashed by its host star.
From observations made in 2011, the researchers saw signs that the planet's atmosphere was evaporating, releasing strong bursts of gas at a staggering rate of at least 984 tons per second, the researchers said. The study's findings offered an intriguing view of changing climates and space weather on alien planets outside our solar system.
"We hadn't just confirmed that some planets' atmosphere evaporate, we had watched the physical conditions in the evaporating atmosphere vary over time," study leader Alain Lecavelier des Etangs, of the National Center for Scientific Research in France, said in a statement. "Nobody had done that before."
A hot, hot world
HD 189733b is a gas giant planet similar to Jupiter, but orbits extremely close to its star, just one-thirtieth of the distance between Earth and the sun. While the parent star, named HD 189733A, is slightly smaller and cooler than the sun, the climate of the alien world is still exceptionally hot, with temperatures above 1,830 degrees Fahrenheit (1,000 degrees Celsius). [The Strangest Alien Planets]
The exoplanet's close proximity to its star also means its upper atmosphere is constantly battered by energetic extreme-ultraviolet and X-ray radiation. According to the researchers, this makes HD 189733b a fascinating place to study how stellar activity affects an alien planet's atmosphere.
Lecavelier and his colleagues studied the atmosphere of HD 189733b during two periods in early 2010 and late 2011, as the planet crossed in front of its parent star and created a silhouette.
This natural backlighting enables astronomers to detect the chemical signatures of the planet's atmosphere on the starlight. Essentially, this process helps scientists read the chemical fingerprint of a planet's atmosphere when it is too far away to image directly.
The astronomers were keen to confirm results from a 2004 study of a different exoplanet, called HD 209458b. In that previous study, oxygen and carbon was seen evaporating off the planet at an immense rate.
But for this new study, it took more than just one look.