Wolf-Rayet stars are among the most massive, luminous and difficult to detect. They represent a very brief transition stage in the life cycles of massive stars as their nuclear fuel is exhausted and their outer layers are blown off to form huge halos of gas and dust. Last year, in one of the first science observations made by the James Webb Space Telescope, Wolf-Rayet 124 was imaged, revealing a spectacular infrared tapestry of clumpy gas and dust nebulae surrounding the central core. The star, 15,000 light years away in the constellation Sagitta, is 30 times more massive than the Sun and has blown off 10 solar masses of material spanning some 10 light years. Webb’s infrared observations reveal never-before-seen features that may shed light on the size of the dust grains and whether they might survive an eventual supernova blast to seed surrounding space with the raw materials for another generation of stars and planets.
Three potentially habitable worlds found orbiting nearby ultra-cool dwarf star
Astronomers have discovered three planets orbiting an ultra-cool 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.
James Webb Space Telescope mirror installation halfway complete
Inside NASA’s Goddard Space Flight Center’s massive clean room in Greenbelt, Maryland, the ninth flight mirror was installed onto the James Webb Space Telescope’s structure with a robotic arm. After being pieced together, all 18 primary mirror segments will work together as one large 6.5-metre mirror. The full installation is expected to be complete early in 2016.