The latest Picture of the Month captured by the NASA/ESA/CSA James Webb Space Telescope unveils intricate details of Herbig Haro object 797 (HH 797). These luminous regions surround newborn stars, known as protostars, forming when stellar winds or jets of gas collide with nearby gas and dust at high speeds, creating shockwaves.
Dominating the lower half of the image, HH 797 is situated near the young open star cluster IC 348, located at the eastern edge of the Perseus dark cloud complex. In the upper portion of the image, bright infrared objects are believed to host two additional protostars.
Using Webb's Near-InfraRed Camera (NIRCam), this image showcases the power of infrared imaging in studying newborn stars and their outflows. Infrared light emitted by molecules like molecular hydrogen and carbon monoxide, excited by turbulent conditions, allows Webb to visualize the structure of these outflows. NIRCam excels in observing hot molecules, reaching temperatures in the thousands of degrees Celsius, excited by shocks.
Previous ground-based observations revealed that for the cold molecular gas associated with HH 797, red-shifted gas (moving away) is mainly found to the south (bottom right), while blue-shifted gas (moving towards) is prevalent to the north (bottom left). In this higher-resolution Webb image, it becomes evident that what was initially perceived as one outflow consists of two nearly parallel outflows, each with distinct series of shocks, clarifying the velocity asymmetries. The source in the small dark region (bottom right of center), known from prior observations, is not a single but a double star, each producing its own dramatic outflow.
Additional outflows, including one from the protostar in the top right of center along with its illuminated cavity walls, are also visible in this image. HH 797 is located directly north of HH 211, as featured in a Webb image release in September 2023, separated by approximately 30 arcseconds.
Source: European Space Agency