Atmosphere Found Around Earth-Like Planet, 39 Light-Years Away
Scientists, including those at the Max Planck Institute for Astronomy in Germany, studied the planet known as GJ 1132b, which is 1.4 times the size of our planet.
They imagined the star host of the planet, GJ 1132, and measured the slight decrease in brightness as the planet and its atmosphere absorbed some of the starlight, passing directly in front of their host star.
The detection of an atmosphere around the super-Earth GJ 1132b marks the first time that an atmosphere has been detected around a planet with a mass and a radius close to mass and terrestrial radius (1.6 earth mass , 1.4 rays), researchers said.
With the present observation we have taken the first provisional measurements in the analysis of the atmosphere of smaller planets of lower mass which are much more terrestrial in size and mass. Researchers
GJ 1132b wears the red dwarf star GJ 1132 in the southern constellation Vela, at a distance of 39 light-years from us.
The team used the GROND imager at the ESO / MPG telescope 2.2 m from the Southern European Observatory in Chile to observe the planet simultaneously in seven bands of different wavelengths.
GJ 1132b is a transiting planet: from the point of view of an observer on Earth, it passes directly in front of its star every 1.6 days, blocking part of the light of the star.
The size of stars like GJ 1132 is well known from stellar models. From the fraction of starlight blocked by the planet, astronomers can deduce the size of the planet - in this case, about 1.4 times the size of the Earth.
The new observations showed that the planet was larger at one of the infrared wavelengths than the others. This suggests the presence of an atmosphere that is opaque to this specific infrared light (making the planet larger) but transparent to all others.
Different possible versions of the atmosphere were then simulated by members of the University of Cambridge team and the Max Planck Institute for Astronomy. According to these models, an atmosphere rich in water and methane would explain the observations very well.
Observations to date do not provide sufficient data to decide how similar or different GJ 1132b is to Earth.
Opportunities include a "water world" with a warm steam atmosphere, researchers said.
GJ 1132b offers a counter-hope of an atmosphere that lasted for billions of years. Given the large number of dwarf stars, such atmospheres could mean that pre-life conditions are fairly widespread in the universe.
The research was published in the Journal astronomique.