Scientists at the University College London detected hydrogen and helium in the atmosphere of the super-Earth 55 Cancri e. The finding, which will be published in the Astrophysical Journal, does not show the presence of water vapour and was made possible by the Wide Field Camera 3 (WFC3) on board the NASA/ESA Hubble Space Telescope.
The 55 Cancri e has been called the diamond planet because astronomers thought that its interior was rich in carbon. According to Angelos Tsiaras, a Ph.D. student at UCL who developed the analysis technique, its massive amounts of hydrogen and helium are believed to be from the nebula from which it formed. The WFC3 has been used to study other super-Earths but no spectral fingerprints or features were found.
Giovanna Tinetti, a professor of physics and astronomy at the university, adds that the result provides information about what a super-Earth is like. This has implications in the further understanding of 55 Cancri e and other super-Earths.
The researchers also say that this may indicate the presence of hydrogen cyanide, a trait of carbon-rich atmospheres. Olivia Venot, who developed the chemical model that backed up the analysis, remarks that this signifies the high ratio of carbon to oxygen.
However, Jonathan Tennyson, also a professor of physics and astronomy in UCL, points out that hydrogen cyanide or prussic acid is poisonous so a planet with it is inhabitable. Nevertheless, the professor echoes the idea that this exoplanet is a carbon-rich and exotic place and more discoveries would be possible with the help of upgraded infrared telescopes.
Super-Earths have a mass larger than the Earth but smaller than the gas giants in the Solar System. A year in 55 Cancri e only lasts about 18 hours and its temperatures are thought to reach 2,000 degrees Celsius. This exotic planet is located in a solar system around the star 55 Cancri, which can be found in the Cancer constellation, 40 light-years away from Earth.