MOA-2007-BLG-192Lb

MOA -2007- BLG - 192Lb is an extrasolar planet orbiting the dwarf star MOA -2007- BLG - 192L in the constellation Sagittarius. It is located about 3,000 light- years away and has about 3.3 Earth masses. He is one of the smallest known exoplanets. MOA -2007- BLG - 192Lb was discovered on 30 May 2008.

Characteristics

MOA -2007- BLG - 192Lb orbiting its star at about the same distance as Venus orbits the Sun. The star has about six to eight percent of the solar mass. With this mass, it is on the borderline between real stars, the hydrogen fuse into helium by nuclear fusion, and brown dwarfs.

According to researchers at the presentation of the dwarf star shines weak and lilac on the sky of MOA -2007- BLG - 192Lb. Outside of the planet's atmosphere prevailing cold temperatures that are roughly comparable to those on the remote dwarf planet Pluto. MOA -2007- BLG 192Lb but probably has a thickness atmosphere permits higher temperatures.

Observation

The observation of such exoplanets is only possible indirectly, because the object is much too small and faint to see it directly. The method used here is called micro - lensing (English micro -lensing ). This required the earth, the observed planet with its host star and a star lying behind lying in a line to the discovery date.

After an effect of general relativity, the observed planet bundled the light of the underlying star, like a magnifying glass. Characterized the relative movement caused by MOA -2007- BLG 192Lb and the background current rating to a brightness variation, resulting from gravitational effects. A detailed analysis of the brightness fluctuations made ​​it possible to determine the mass of the planet and its star.

Importance

Until the discovery of MOA -2007- BLG - 192Lb you have never tracked a planet that orbits a star with less than 20 percent of the solar mass. According to the researchers, this planet shows that one can expect planets around stars with low mass in the future, especially in stars in the neighborhood of our solar system (as of 2010). The special importance arises from the possibility that one could observe such close exoplanets with the new James Webb Space Telescope directly. In contrast, one could such planets so far only indirectly observed (see section observation).

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