For the first time, researchers have successfully detected the presence of gases in the atmosphere of a super-Earth, an exoplanet with a mass higher than that of our homeworld but far less than an ice giant such as Uranus or Neptune, a soon-to-be-published study has revealed.

In the paper, which has been accepted for publication in the Astrophysical Journal, University College London PhD student Angelos Tsiaras and his colleagues used new processing methods to look at data from the Hubble Space Telescope, and were able to locate the presence of helium and hydrogen in the atmosphere of the exoplanet 55 Cancri e.

Also known as the diamond planet because models based on its mass and radius have led some astronomers to speculate that it has a carbon-rich interior, 55 Cancri e is more than 8.5 times as massive as the Earth and has a diameter about twice that of our planet. One year there lasts just 18 hours, and its surface temperatures are believed to reach nearly 2,000 degrees Celsius.

55 Cancri e is located in a solar system located about 40 light-years from Earth, in the Cancer constellation. The star around which it orbits, 55 Cancri, is so bright that the UCL astronomers were able to use Hubble's Wide Field Camera 3 (WFC3) instrument to study the spectra of the star, and use this data to learn more about its super-Earth companion.

Analysis also revealed evidence that 55 Cancri e is carbon-rich

By scanning WFC3 rapidly across the star, the researchers created a number of spectra and then took the data and processed it using special analytic 'pipeline' software. By doing so, they could retrieve the spectral fingerprints of 55 Cancri e embedded in the starlight, which enabled them to detect hydrogen and helium (but not water vapor) in its atmosphere.