Seven Earth-sized planets have been discovered orbiting a single ultra-cool dwarf star 40 light years away. Depending on atmospheric conditions, all seven could potentially be habitable, making the system a prime target for scientists hunting for another Earth. The planets were discovered in the TRAPPIST-1 system by a team led by Michaël Gillon, of the University of Liège in Belgium. TRAPPIST-1 is named for the TRAnsiting Planets and PlanetesImals Small Telescope, which is actually two 0.6-metre telescopes located in Chile and Morocco that together monitor 60 ultracool dwarf stars and brown dwarfs, looking for evidence of exoplanets. Three of TRAPPIST-1’s planets – b, c and d – were discovered using the TRAPPIST-South telescope in Chile by Gillon and his team last year. The additional four new planets make the TRAPPIST-1 system the first planetary system known to host so many Earth-sized worlds, not to mention potentially habitable worlds. All seven planets transit their star; that is, they cross in front of the star’s disc, blocking some of the starlight. The amount of light each planet blocks tells us their diameters, and how regularly they transit tells us their orbital period, from which we can calculate their distance from the star.
An international team of astronomers released the largest-ever compilation of exoplanet-detecting observations made using a technique called the radial velocity method. They demonstrated how these observations can be used to hunt for planets by detecting more than 100 potential exoplanets, including one orbiting the fourth-closest star to our own Solar System, which is about 8.1 light years away from Earth.
Searching for planets around other stars is a tricky business. They’re so small and faint that it’s hard to spot them. But a possible planet in a nearby stellar system may be betraying its presence in a unique way: by a shadow that is sweeping across the face of a vast pancake-shaped gas-and-dust disk surrounding a young star.
Breakthrough Listen, the 10-year, $100-million astronomical search for intelligent life beyond Earth launched in 2015 by Internet entrepreneur Yuri Milner and Stephen Hawking, has just announced its first observations of newly-discovered Earth-size planet Proxima b orbiting the nearest star to the Sun using the Parkes Radio Telescope in New South Wales, Australia.
A group of citizen scientists and professional astronomers joined forces to discover an unusual hunting ground for exoplanets. They found a red dwarf, called AWI0005x3s, surrounded by the oldest known circumstellar disc — a 45-million-year-old primordial ring of gas and dust orbiting the star from which planets can form.
Like cosmic ballet dancers, the stars of the Pleiades cluster are spinning, but all at different speeds. By watching these stellar dancers, NASA’s Kepler space telescope has helped amass the most complete catalogue of rotation periods for stars in a cluster. This information can provide insight into where and how planets form around these stars, and how such stars evolve.