September 18, 2023 at 2:24 p.m.
It is impressive what the infrared tools of the James Webb Space Telescope have managed to capture. NASA publishes an image showing the first supersonic flows from a massive star, very similar to our Sun.
What are supersonic flows? They are also known as stellar jet. It is a jet of gas and plasma that is ejected from the surface of a star at a speed greater than the speed of sound. Stellar jets can be found in a variety of stars, including newly formed stars, binary stars, and dying stars.
Stellar jets form when a star’s magnetic field interacts with its accretion disk, which is nothing more than a shell of gas and dust that surrounds a forming star. The star’s magnetic field traps gas and dust from the accretion disk, accelerating it to supersonic speeds.
These phenomena can have a significant impact on a star’s environment. They can eject material from the accretion disk, which can affect star formation. They can also interact with surrounding gas and dust, which can lead to the formation of nebulae.
The supersonic flow: a star in birth
The James Webb Space Telescope reveals an output from a Class 0 protostar, an infant analogue of ours Sun when it was only a few tens of thousands of years old and with a mass of only 8% of today’s. (in time it will become a star like ours).
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.
The infrared emission from the star’s outflows then penetrates the obscuring gas and dust, making a Herbig-Haro object like HH 211 ideal for observation with James Webb’s sensitive infrared instruments. Molecules excited by turbulent conditions, including molecular hydrogen, carbon monoxide and silicon monoxide, emit infrared light that Webb can collect to map the structure of the outflows, NASA notes in its statement.
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. The space telescope reveals this scene in unprecedented detail: approximately 5 to 10 times greater spatial resolution than any previous image of HH 211.
