Friday, 21 June 2013

Discovered planet "that should not be"

Astronomers have discovered a planet that forms a surprisingly far from its star, 12 billion miles, which could completely change our knowledge of these processes.Researchers using the Hubble Space Telescope observed a large gap between the disk of matter that formed the planet and red dwarf star TW Hydra, located in the constellation of Hydra, about 176 light-years from Earth, reports portal "Space".Its remote position brings confusion in the leading theory of planet formation, which says that they are formed slowly, over tens of millions of years, picking up gas, dust and stones from the protoplanetary disk.The process continues slowly, at relatively large distances from the star, because the orbital velocity decrease and there is less material in the outer area of ​​the disc.A planet from its sun 12 billion kilometers should be 200 times longer to form than Jupiter, the slower orbital speed and the lack of material in the disk. Jupiter is from the Sun is 805 million kilometers, formed 10 million years ago. TW Hydra, on the other hand, care only eight million years ago, which means it is unlikely that there is any planet - theoretically speaking.Another complication is its weight, which is 55 percent of the sun, led by NASA."An intriguing to see such a system. This is a star with the lowest weight so far and so away from the gap, "says John Debs from the Institute for Space telescopes in Baltimore, the leader of the research.An alternative idea, which tells us that planets can form very quickly, within a few tens of thousands of years ago, when pieces of protoplanetary disk becomes gravitationally unstable and hitting each other. But even in such a scenario, it is not clear how it could be formed by low-mass planets, the researchers found."When the weight of the object for which it is considered that the planet is low such as in this case, that's a real puzzle. In theory would say that something can not exist! "He said in a statement astrophysicist Alan Boss, of the Institute for Science" Carnegie "in Washington.The research is published online in the Journal of Astrophysics (The Astrophysical Journal).

Not even a small stones

Gap, low weight, but this is not the hassle - TW Hydra system lacks the larger dust grains in the outer regions. Observations from Chile show that the grain size of the sand has 8.9 billion miles from the star, just the conduit.

"You need the gems before they get the planet. And when you have a planet no larger than a grain of dust, sand, then you have a great challenge to traditional models of planet formation, "said study leader Debs.

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