Herbig-Haro objects are luminous regions that surround newborn stars (known as protostars) and form when stellar winds or gas jets are ejected from these newborn stars. form shock waves that collide with nearby gas and dust at high speeds.
HH 797, which dominates the lower half of this image, is located near the young open star cluster IC 348, located near the eastern edge of the Perseus dark cloud complex. The bright infrared objects at the top of the image are thought to host two other protostars.
This image was captured using Webb’s Near Infrared Camera (NIRCam). Infrared images are powerful for studying newborn stars and their outflows, because young stars are often embedded in the gas and dust from which they formed. The infrared emission from the star streams penetrates the obscuring gas and dust, making Herbig-Haro objects ideal for observation with Webb’s sensitive infrared instruments. Molecules excited by turbulent conditions, including molecular hydrogen and carbon monoxide, emit infrared light that Webb can collect to visualize the structure of the flows. NIRCam is particularly good at observing hot (thousands of degrees Celsius) molecules excited by collisions, NASA reports.
Using ground-based observations, researchers previously discovered that for the cold molecular gas associated with HH 797, most of the redshifted gas (away from us) is located to the south (lower right), while the gas is -blueshifted (moved towards us) is in the north (lower left). A gradient along the flow is also found, such that at a distance from the young central star, the gas velocity near the eastern edge of the jet is redshifted more than the gas on the west edge.
Previously, astronomers thought it was due to the swirling flow. However, in this higher resolution Webb image we can see that what is thought to be a single outflow is actually formed by two nearly identical flows with their own distinct series of oscillations (which explains the speed asymmetries). The source, located in the small dark region (lower right of center), and already known from previous observations, is not a star, but a double. Each star produces its own dramatic flow. Other outflows are also visible in this image, including one from the protostar in the upper right center with its illuminated cavity walls.