The young star B335, which hasn't grown up yet, suddenly sneezed, and that sneeze is still going on. Astronomers spotted the outburst in the scattered light from its outflow cavity, and it offered a rare chance to see how such an energy release affects a jet — a stream of gas shooting out from the star's vicinity.
Using the near-infrared camera on the James Webb Space Telescope, scientists measured how light from distant stars passing through the cloud around B335 is dimmed by dust and absorbed by water ice. It turned out that the outflow has carved a real cavity in the molecular cloud, like someone cut a tunnel through a snowdrift. This allowed them to see the inner parts of the cloud that are usually hidden from us.
The most prominent shock front, named 3E, matches the beginning of the current outburst in age. This means it was produced by this very event. The younger front, 2E, shows lines of ionized elements but no molecular emission, while 3E already glows in carbon monoxide, hydrogen, and iron. The older fronts are fainter and consist mostly of hydrogen and iron.
Near the star, once the carbon monoxide lines are removed, you can see how strongly the absorption by ice made of carbon dioxide, cyanate ions, and carbon monosulfide increases. This means that in the deepest layers of the cloud, right next to the protostar, there is especially much ice. But otherwise, the ice properties are the same as along less dense lines of sight.
Thus, the B335 outburst has allowed us to peer into the very heart of the cold cloud where a star is being born and see how its turbulent youth shapes the surrounding space.
The shock wave from the B335 outburst travels at up to 227 km/s—200 times faster than a bullet fired from a rifle.