Glowing methane has been detected in the upper atmosphere of a Jupiter-sized planet orbiting very closely to its star.

This artist's drawing shows the Jupiter-sized planet HD 189733b orbiting very closely to its star. (ESA, NASA and G. Tinetti/University College London)

The planet, called HD 189733b, is orbiting a star about 63 light-years away in the constellation Vulpecula, the fox.

Astronomers used the three-metre NASA Infrared Telescope at the top of Mauna Kea in Hawaii to detect the methane as it glowed under the radiation of its sun.

HD 189733b completes an orbit once every 2.2 days at a distance of 4.6 million kilometres from its star, or just one-tenth of the closest distance between Mercury and the sun.

The fluorescence of methane has also been observed in the atmospheres of Jupiter, Saturn and Titan, one of Saturn's moons. The process is similar to the one that causes gases in the Earth's atmosphere to glow during the northern lights.

Astronomers using space telescopes have previously discovered methane in the atmospheres of planets outside our solar system, or exoplanets. Methane is considered part of the basic chemistry of life because it contains a carbon atom.

This research, led by Mark Swain of NASA's Jet Propulsion Laboratory and published this week in the journal Nature, used data from the Hawaii telescope, and the Hubble and Spitzer space telescopes to get a complete picture of what's happening on the distant gas giant planet.

Certain parts of the infrared spectrum aren't accessible to the space telescopes, but in that spectral region "ground-based observations provide a unique capability," the astronomers wrote in Nature.

"We believe the calibration method used here can be applied directly to many existing instruments," the researchers wrote.

The researchers said the technique could be used in other ground-based telescopes, meaning future discoveries in exoplanet astronomy wouldn't all be coming from space telescopes.