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Source.
Tau Ceti has long been a science fiction favourite for planets, featuring in episodes of Star Trek as well as classic works from the writers such as Isaac Isamov, Arthur C Clarke and Robert Heinlein.
Now an international team of astronomers has discovered that the star may host five planets orbiting around it, including one in the so-called habitable zone.
Tau Ceti is one of the closest stars to the Earth at a distance of only 12 light years which will make its planetary system a leading candidate to examine any signs of life. In fact it has already been a prime target for the Search for Extra-Terrestrial Intelligence (SETI) team before this new discovery was made
The astronomers, from the USA, UK, Chile and Australia, have combined more than 6,000 observations using spectrographs on three giant telescopes - the 3.6 metre telescope at the European Southern Observatory in La Silla, Chile, the Anglo-Australian Telescope in Siding Spring, Australia, and the 10 metre Keck telescope on Mauna Kea, Hawaii. They then used a computer-modelling technique to pick out signals from smaller worlds that can be usually detected.
The allowed them to conclude that there are five planets in the Tau Ceti system with masses between two and six times that of the Earth. One which lies in the zone where water could exist in a liquid state is about five times more massive than Earth. That makes it the smallest planet yet found in the habitable zone of a star like the sun.
More than 800 extrasolar planets have been discovered in the last 20 years, the bulk of them huge gaseous worlds dubbed "hot Jupiters". But nearby stars are of special interest because smaller worlds in orbit around them will be easier to find.
The latest discovery is being announced in a paper accepted for publication in the journal Astronomy & Astrophysics, and comes two months after it was revealed that an Earth-sized planet is in orbit around Alpha Centauri B, a star in the closest solar system to Earth, just 4.3 light-years away.
Pretty interesting.