The astronomers have said that the super-Earth – 40 light years from our planet – may have a water-rich atmosphere.
A team of astronomers investigated whether this planet has an atmosphere rich in water or hydrogen. Following a blue light observations of a super-Earth the scientists have made the indications. Japanese astronomers and planetary scientists used Subaru Telescope’s two optical cameras, Suprime-Cam and the Faint Object Camera and Spectrograph (FOCAS), with a blue transmission filter to observe planetary transits of Super-Earth GJ 1214 b (Gliese 1214b).
GJ 1214 b is located in the constellation Ophiuchus, northwest of the center of our Milky Way galaxy.
This planet is one of the well-known super-Earths discovered by Charbonneau et. al. (2009) in the MEarth Project, which focuses on finding habitable planets around nearby small stars.
The Subaru observation showed that the atmosphere of this planet does not show a strong Rayleigh scattering feature. This predicts the presence of a cloudless hydrogen-dominated atmosphere.
Strong Rayleigh scattering in the optical wavelength is powerful evidence for a hydrogen-dominated atmosphere. Rayleigh scattering occurs when light particles scatter in a medium without a change in wavelength. Such scattering strongly depends on wavelength and enhances short wavelengths; it causes greater transit depth in the blue rather than in the red wavelength.
When combined with the findings of previous observations in other colors, this new observational result implies that GJ 1214 b is likely to have a water-rich atmosphere.
Super-Earths are emerging as a new type of exoplanet with a mass and radius larger than the earth’s but less than those of ice giants in our Solar System, such as Uranus or Neptune.
The element hydrogen is a major component of a protoplanetary disk and water ice is abundant in an outer region beyond the so-called “snow line.” Findings about where super-earths have formed and how they have migrated to their current orbits point to the prediction that hydrogen or water vapor is a major atmospheric component of a super-Earth, researchers said.