Source Pravda.Ru

Magnifier enables scientists to see other planets

Astronomers have discovered a planet orbiting a distant star some 17,000 light years away by using a sort of interstellar magnifying glass to look into the centre of the galaxy.

The achievement marks the first time a technique known as gravitational microlensing has been used to find a planet orbiting around a star outside of Earth's solar system.

Originally predicted by Albert Einstein in his theory of relativity, the technique works under the hypothesis that the gravity of stars or planets can focus light, brightening stars or planets that lie far away.

Researchers have identified more than 100 extra-solar planets by observing slight wobbles in a star's trajectory caused by a planet's orbit or by observing small changes in a star's brightness when a planet passes in front of it, report

It was found because, as seen from the Earth, it passed in front of a more distant star and its gravity amplified the background star's light.

This "gravitational lensing" effect was predicted by Albert Einstein in his General Theory of Relativity.

Nasa says that the way the background star's brightness changed revealed the existence of the planet circling it.

The gravitational field of a foreground star bends and focuses light from a background star, like a lens in a telescope, but only if the foreground and background star are precisely aligned. The newly discovered planet is deep in the constellation of Sagittarius and orbits a dim so-called red-dwarf star.

The planet is probably about one-and-a-half times the mass of Jupiter and orbits its star about three times farther apart than the Earth orbits the Sun, inform BBC.

According to the planet, orbiting a red dwarf parent star, is larger than Jupiter and is three times farther from its star than the earth is from the sun.

The combined gravity of the planet and the star created a sort of cosmic magnifying glass, and lit up an even more distant star that is 24 000 light-years away, near the centre of the Milky Way. The only problem with the system is that the magnifying effect only works when two stars are perfectly aligned.