Skip to: Content
Skip to: Site Navigation
Skip to: Search

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. 

By / June 28, 2012

This artist’s impression shows exoplanet HD 189733b, as it passes in front of its parent star, called HD 189733A. Hubble’s instruments observed the system in 2010, and in 2011 following a large flare from the star (depicted in the image).

L. Calçada/NASA, ESA,


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
The Hubble Space Telescope has seen a burst of evaporation in the upper atmosphere of exoplanet HD 189733b following a intense flare from its parent star - leading scientists to believe that the extreme x-ray radiation from the flare is the culprit.
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.

Read Comments

View reader comments | Comment on this story

  • Weekly review of global news and ideas
  • Balanced, insightful and trustworthy
  • Subscribe in print or digital

Special Offer


Doing Good


What happens when ordinary people decide to pay it forward? Extraordinary change...

Danny Bent poses at the starting line of the Boston Marathon in Hopkinton, Mass.

After the Boston Marathon bombings, Danny Bent took on a cross-country challenge

The athlete-adventurer co-founded a relay run called One Run for Boston that started in Los Angeles and ended at the marathon finish line to raise funds for victims.

Become a fan! Follow us! Google+ YouTube See our feeds!