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.
NASA has successfully installed the first of 18 flight mirrors onto the James Webb Space Telescope — the successor to Hubble — beginning a critical piece of the observatory’s construction. Targeted for launch in 2018, the telescope’s 18 primary mirror segments will work together as one large 21.3-foot (6.5-metre) mirror.