Hubble Reveals a Dry Atmosphere Around Super-Earth 55 Cancri e

photo credit: Artist's impression of the super-Earth 55 Cancri e. ESA/Hubble/M. Kornmesser

Using Hubble Space Telescope data and a new analysis technique, astronomers have successfully detected the atmospheric composition of exoplanet 55 Cancri e. It's a dry atmosphere mainly consisting of hydrogen and helium.

For the first time astronomers were able to analyze the atmosphere of an exoplanet in the class known as super-Earths. Using data gathered with the NASA/ESA Hubble Space Telescope and new analysis techniques, the exoplanet 55 Cancri e is revealed to have a dry atmosphere without any indications of water vapor. The results, to be published in the Astrophysical Journal, indicate that the atmosphere consists mainly of hydrogen and helium.

The international team, led by scientists from University College London (UCL) in the UK, took observations of the nearby exoplanet 55 Cancri e, a super-Earth with a mass of eight Earth-masses. It is located in the planetary system of 55 Cancri, a star about 40 light-years from Earth.

“This is a very exciting result because it’s the first time that we have been able to find the spectral fingerprints that show the gases present in the atmosphere of a super-Earth,” said Angelos Tsiaras, a Ph.D. student at the University College London, where the research was led, in a statement. The results are to be published in the Astrophysical Journal, with a pre-print available on Arxiv. 

“If the presence of hydrogen cyanide and other molecules is confirmed in a few years time by the next generation of infrared telescopes, it would support the theory that this planet is indeed carbon rich and a very exotic place,” said Professor Jonathan Tennyson, also from UCL, in the statement. “Although, hydrogen cyanide or prussic acid [as it’s sometimes called] is highly poisonous, so it is perhaps not a planet I would like to live on!”

In their paper, the researchers note that the discovery of an atmosphere is a significant finding in itself, especially considering the planet’s position around its star. They postulate that its hydrogen and helium may have been retained from the protoplanetary disk from which it formed.

55 Cancri e is unlikely to be the norm for super-Earths, but the techniques used here could support analysis of other such worlds.

Source: Hubble Space Telescope | space.com