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In the system Tau Ceti is detected candidates in five planets. The intrigue is that this is the nearest to us was shining with the temperature and luminosity, very close to the sun. And if the planet really there, one of them may be at the right distance from the star, and then on its surface can be mild temperatures, liquid water and even life.
But do not rush to go: open to be demonstrated.
To Tau Ceti 12 light years, it is only three times on our nearest stellar neighbor alpha Centauri. Tau Ceti is reminiscent of the Sun so much that the astronomer Frank Drake, known enthusiast search of extraterrestrial civilizations, in the 1960-ies has identified it as a priority goal. Unlike most stars weak, cold and small - Tau Ceti belongs to G-class main sequence than can only boast of a single star of twenty-five. In addition, unlike the alpha Centauri, which is also G, and which also has a planet, Tau Ceti is not married, there is no partner with gravity, is able to take away from her planet.
Astronomer Mikko Twomey out at the University of Hertfordshire (UK) and colleagues analyzed the results of over 6 thousand observations of the stars, made telescopes Chile, Australia and Hawaii. According to scientists, small changes in the movement of the Tau Ceti through space can be a reaction to the gravitational tug of five planets that are more massive than the Earth just 2-7 times.
If this is true, then all five planets closer to its star than Mars to the Sun, however, the Tau Ceti emits only 45% of the light in comparison with the Sun, so the planet receive less heat. Three inner planets - b, c and d - probably too hot for life (year there continues 14, 35 and 94 earth day, respectively; on mercury, for comparison, is 88 days).
All hope is on the fourth planet - e, although it about four times more massive than the Earth. Year lasts 168 earth days (on Venus - 224,7). The fifth and the most distant planet - f - flies shone over 640 days (Mars - for 686,98).
Scientists warn, however, that the speed Tau Ceti may change, but because the planet and may be at anything. "They are too deeply buried in the noise, - said Sara Seager of the Massachusetts Institute of technology (USA). Astronomers reluctant to recognize the discovery of planets on signals, found deep in the noise".
"They are trying to go beyond the established framework, - justifies colleagues Gregory Laughlin of the University of California at Santa Cruz (USA). - Some or almost all of the planet can then be a mistake, but, in my opinion, they pulled out all data possible. Have to do tons and tons and tons of speed measurement for many years, and then to treat them very carefully, to get rid of systematic noise. It is a group Twomey".
The team member Chris tinni from the University of New South Wales (Australia) recognizes all possible risk of error, but it says that the verification opening could ask for ten years, and scientists did not want to wait that long. They decided that it is better to publish the results - in order to include in the discussion as much as possible specialists.
Tau Ceti is about twice older than the Sun, and this means that if a suitable planet exists, the local life became more complicated form than Homo sapiens. Perhaps this can explain the fact that there is no one with us, primitives, until contacted.
The study is published in the journal Astronomy & Astrophysics.
Based on the materials ScienceNOW.