Three Potentially Habitable Worlds Found Around Nearby Ultracool Dwarf Star
Astronomers using the TRAPPIST telescope at ESO’s La Silla Observatory have discovered three planets orbiting an ultracool dwarf star just 40 light-years from Earth.
These worlds have sizes and temperatures similar to those of Venus and Earth and are the best targets found so far for the search for life outside the Solar System. They are the first planets ever discovered around such a tiny and dim star. The new results will be published in the journal Nature on 2 May 2016.A team of astronomers led by Michaël Gillon, of the Institut d'Astrophysique et Géophysique at the University of Liège in Belgium, have used the Belgian TRAPPIST telescope to observe the star 2MASS J23062928-0502285 now also known as TRAPPIST-1. They found that this dim and cool star faded slightly at regular intervals, indicating that several objects were passing between the star and the Earth. Detailed analysis showed that three planets with similar sizes to the Earth were present.
TRAPPIST-1 is an ultracool dwarf star – it is much cooler and redder than the Sun and barely larger than Jupiter. Such stars are both very common in the Milky Way and very long-lived, but this is the first time that planets have been found around one of them. Despite being so close to the Earth, this star is too dim and too red to be seen with the naked eye or even visually with a large amateur telescope. It lies in the constellation of Aquarius (The Water Carrier).
Emmanuël Jehin, a co-author of the new study, is excited: “This really is a paradigm shift with regards to the planet population and the path towards finding life in the Universe. So far, the existence of such ‘red worlds’ orbiting ultra-cool dwarf stars was purely theoretical, butnow we have not just one lonely planet around such a faint red star but a complete system of three planets!”