Scientists capture supersonic outflow of young star using Webb telescope
In a stunning new image captured by the NASA/ESA/CSA James Webb Space Telescope, we are given a glimpse of Herbig-Haro 211 (HH 211), a bipolar jet traveling through interstellar space at supersonic speeds. Located approximately 1000 light-years away from Earth in the constellation Perseus, HH 211 is one of the youngest and closest protostellar outflows, making it an perfect target for the Webb telescope.
Herbig-Haro objects are luminous regions that surround newly formed stars. They are formed when stellar winds or jets of gas expelled from these newborn stars collide with nearby gas and dust at high speeds, creating shockwaves. This spectacular image of HH 211 reveals an outflow from a Class 0 protostar, which is comparable to our Sun when it was only a few tens of thousands of years old and had a mass of just 8% of its current size. In other words, this protostar has the potential to grow into a star similar to our Sun.
Infrared imaging plays a vital role in studying newborn stars and their outflows because these stars are still embedded within the gas from the molecular cloud in which they formed. The infrared emission from the star’s outflows can penetrate the obscuring gas and dust, making Herbig-Haro objects like HH 211 ideal for observation using Webb’s sensitive infrared instruments. Molecules, such as molecular hydrogen, carbon monoxide, and silicon monoxide, which are excited by turbulent conditions, emit infrared light that can be collected by Webb to map out the structure of the outflows.
The image showcases a series of bow shocks to the southeast (lower-left) and northwest (upper-right), as well as the narrow bipolar jet that powers them. Webb’s high spatial resolution provides unprecedented detail, offering roughly 5 to 10 times higher resolution than any previous images of HH 211. The inner jet exhibits a mirror symmetry on either side of the central protostar, which aligns with observations on smaller scales. This finding suggests that the protostar may actually be an unresolved binary star system.
Previous observations of HH 211 using ground-based telescopes revealed giant bow shocks moving away from us in the northwest direction and moving towards us in the southeast direction. Additionally, cavity-like structures were observed in shocked hydrogen and carbon monoxide, while a knotty and wiggling bipolar jet was observed in silicon monoxide. By analyzing these new observations, researchers have determined that HH 211’s outflow is relatively slow compared to more evolved protostars with similar types of outflows.
The team measured the velocities of the innermost outflow structures to be around 80 to 100 kilometers per second. However, the difference in velocity between these sections of the outflow and the leading material they are colliding with, known as the shockwave velocity, is much smaller. Based on these findings, the researchers concluded that outflows from the youngest stars, like the one at the center of HH 211, consist mostly of molecules. The relatively low shockwave velocities are not energetic enough to break the molecules apart into simpler atoms and ions.
The insights gained from this research contribute to our understanding of the early stages of star formation and the intricate processes involved. By studying objects like HH 211 with the advanced capabilities of the James Webb Space Telescope, scientists can unravel the mysteries of protostellar outflows and gain valuable insights into the birth and evolution of stars. The Webb telescope continues to revolutionize our understanding of the cosmos, providing unprecedented details of celestial phenomena that were once beyond our reach.
To learn more about this groundbreaking research and explore further discoveries made possible by the James Webb Space Telescope, visit [link]. This captivating image of HH 211 was captured as part of the Webb Cycle One program #1257.
