The 'super-Earths', with a mass 10 times greater than Earth's, are good candidates to find life outside our solar system.
Located 42 light years away, GJ 1214b is one of the most studied because it can be seen from ground-based telescopes with relative ease
The data obtained with the GTC by IAC researchers support the idea that GJ1214b's atmosphere is made up of metal.
Sometimes important is what is seen for what it is not observed. A team from the Institute de Astrophysical de Canarias (IAC) has found that the atmosphere of the 'super-Earth' GJ 1214b, one of the most known exoplanets that can be seen from Earth with certain telescopes, it is characterized by an excess of hydrogen. The conclusion obtained following observations in the Gran Telescope Canarias (GTC), supports the idea that GJ 1214b has an atmosphere composed of elements of high metallicity.
The study, published in the journal Astronomy & Astrophysics, was led by researchers from the IAC and Enrich Pale Murgas Felipe, who explain the reasons for initiating the project: "Knowing the atmospheric composition of a planet is very important because can reveal the physical conditions in the inner layers of atmosphere. " This type of information is another step to ensure that in the future, scientists can perform these analyzes in other 'super-Earths' potentially habitable.
According Murgas recounts, in the last 20 years has increased considerably the discovery of new exoplanets-those detected outside our solar system, thanks to surveys or large observational campaigns devoted to detection. Within this planetary zoo, a group that raises more curiosity among astrophysicists: the 'super-Earths'. These are planets that have a mass between 2 and 10 times that of Earth, a range that is unmatched in the solar system. However, the resemblance to our planet makes them "good candidates" for the search for life.
Perhaps one of the 'super-Earths' better known as GJ 1214b, discovered in 2009 about 42 light years from Earth, "a close distance in galactic scale," said IAC astrophysicist. However, his fame is not due to its distance from us but his relationship with the star it orbits: because the relative size of the planet from its star is greater than in other cases, it produces eclipses GJ 1214b passing in front of its star cause a significant decrease in brightness that comes from this and therefore observable with telescopes from Earth. "For this reason, there have been numerous studies trying to identify some element or molecule that can determine atmospheric composition," he adds.
However, despite the efforts, "failed to detect any signal attributable to its atmosphere." Pale Murgas and used the instrument of GTC OSIRIS tunable filters to see if the exoplanet had an excess of hydrogen: "In particular, we observe the spectral range where the line should appear atomic transition of hydrogen known as Ha. If GJ 1214b having an atmosphere rich in water vapor, this molecule may be destroyed at higher layers of the atmosphere due to the radiation of the star, generating an excess of hydrogen. “Although there is some margin of error, it seems that this is the case.
So what does the absence of findings? For authors, is to support the theory that GJ 1214b has an atmosphere composed of elements that produce a high metallicity constant absorption wavelength. "If confirmed, the planet would be wrapped in a blanket fog, preventing observe its surface. Just the opposite that on Earth, "said Murgas. "The metallic elements may come from volcanic activity or other mechanisms by which the planet initial atmospheric composition changes over time," IAC astrophysicist concrete. In any case, he continues, the work is a step further to reveal the true nature of GJ 1214b.