Stellar flare sweeps up exoplanet’s atmosphere

Date:3 July 2012 Tags:, ,

The exoplanet HD 189733b lies so near its star that it completes an orbit every 2,2 days. In late 2011, Nasa’s Hubble Space Telescope found that the planet’s upper atmosphere was streaming away at speeds exceeding 480 000 km/h. Just before the Hubble observation, Nasa’s Swift detected the star blasting out a strong X-ray flare, one powerful enough to blow away part of the planet’s atmosphere.

Image credit: Nasa’s Goddard Space Flight Centre

Related article: Hubble and Swift detect first-ever changes in an exoplanet atmosphere