2023-09-14 17:25:03
MADRID, 14 Sep. (EUROPA PRESS) –
The Webb space telescope has captured a child analogue of our Sun when it was only a few tens of thousands of years and with a mass of only 8% of our star.
The protostar is located in the center of HH 211, a Herbig-Haro objecta category that defines the luminous regions surrounding newborn stars, formed when stellar winds or jets of spewing gas form shock waves that collide with nearby gas and dust at high speeds.
Infrared images are powerful for studying newborn stars and their fluxes, because such stars are invariably still embedded within the gas of the molecular cloud in which they formed, NASA reports.
Infrared emission from the star’s outflows penetrates the obscuring gas and dust, making a Herbig-Haro object like HH 211 ideal for observation with Webb’s sensitive infrared instruments. Molecules excited by turbulent conditions, including molecular hydrogen, carbon monoxide, and silicon monoxide, They emit infrared light that Webb can collect to map the structure of the outflows.
The image shows a series of shock arcs to the southeast (bottom left) and northwest (top right), as well as the narrow bipolar jet that drives them. Webb reveals this scene in unprecedented detail: approximately 5 to 10 times greater spatial resolution than any previous image of HH 211. The inner jet is seen to “waggle” with mirror symmetry on either side of the central protostar. This agrees with observations at smaller scales and suggests that the protostar may in fact be an unresolved binary star.
Previous observations of HH 211 with ground-based telescopes revealed giant shock arcs moving away from us (northwest) and toward us (southeast) and cavity-like structures in impacted hydrogen and carbon monoxide, respectively, as well as a knobby bipolar jet and undulating in silicon monoxide. Researchers have used Webb’s new observations to determine that the object’s outflow is relatively slow. compared to more evolved protostars with similar types of outflows.
The team measured the velocities of the innermost exit structures at approximately 80 to 100 kilometers per second. However, the velocity difference between these sections of the outflow flow and the parent material they collide with (the shock wave) is much smaller.
The researchers concluded that emissions from younger stars, such as that at the center of HH 211, are composed primarily of molecules, because the comparatively low velocities of the shock waves They are not energetic enough to split molecules into simpler atoms and ions.
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