Puffed-up Atmosphere of a Star-hugging Gas Giant Planet

Puffed-up Atmosphere of a Star-hugging Gas Giant Planet

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Fast Facts
News release ID: STScI-2007-07
Release Date: Jan 31, 2007
Image Use: Copyright
About this image

This artist's illustration shows an extrasolar planet orbiting very close to its host star. The planet designated HD 209458b, is about the size of Jupiter. Unlike Jupiter, the planet is so hot that its atmosphere is "puffed up." Starlight is heating the planet's atmosphere, causing hot gas to escape into space, like steam rising from a boiler.

HD 209458b completes an orbit every 3.5 days. The Hubble Space Telescope could not image the planet directly because it is too close to the star. Astronomers used Hubble to analyze the starlight that filtered through the planet's atmosphere. Imprinted on the starlight is information about the atmosphere's structure and chemical makeup.

Artwork, Exoplanets, Hubble Telescope, Infographics, Planets, Stars


NASA, ESA, and G. Bacon (STScI)