First-of-its-kind identification of straight jets in spectacular new Webb Space Telescope image
For the first time, a phenomenon that astronomers have long hoped to photograph directly has been captured by the Near Infrared Camera (NIRCam) of the NASA/ESA/CSA James Webb Space Telescope. In the spectacular image of the Serpent Nebula, the discovery is in the northern region of this young, nearby star-forming region.
The astronomers found an interesting group of protostellar flows, which form when jets of gas form from new stars and collide with nearby gas and dust at high speeds. Usually these objects have a variety of orientations within one area. Here, however, they all tend in the same direction, to the same extent, like frozen rain falling during a storm.
The discovery of these straight objects, which became possible only thanks to the incredible spatial resolution and sensitivity of 'WEB' in near infrared wavelengths, provides information on the fundamental question of how stars are formed.
So how exactly is the alignment of the stellar jets related to the rotation of the star? When an interstellar gas cloud collapses in on itself to form a star, it spins faster. The only way for the gas to keep moving in is for some of the rotation (known as angular momentum) to be removed. A disk of material forms around the young star to transport material down, like a vortex around a drain. Magnetic fields that rotate in the inner disk launch some of the material into twin jets that go out in opposite directions, perpendicular to the material disk.
In the Webb image, these jets are identified by bright red clumpy streaks, which are shock waves created when the jet hits the surrounding gas and dust. Here, the red color indicates the presence of molecular hydrogen and carbon monoxide. Webb can image these very young stars and their flows, previously blocked by optical wavelengths.
Astronomers say there are several forces that can change the direction of the flows during this period of a young star's life. One way is when binary stars orbit each other and oscillate in orientation, rotating the direction of the flows over time.
The Serpent Nebula
The Serpent Nebula is only a million or two million years old, very young in cosmic terms. It is also home to an extremely dense cluster of newly formed stars (about 100,000 years old) at the center of this image, some of which will eventually grow to the mass of our Sun.
The Serpent Nebula is a reflection nebula, meaning it is a cloud of gas and dust that does not create its own light but glows in the reflection of light from nearby stars or within the nebula.
Thus, throughout the region in this image, fibers and ghosts of different hues represent reflected starlight from stars still forming within the cloud. Some areas have dust from before this reflection, which appears here as a diffuse orange tint.
(Other serendipitous discoveries have been made in this area, including the "flapping bat" shadow, which got its name when data from 2020 from NASA/ESA's Hubble Space Telescope revealed that it was flapping, or moving. This feature is seen in the center of Webb's image.
future studies
The spectacular image and serendipitous discovery of the aligned objects are actually just the first step in this scientific program. The team will now use Webb's Near-InfraRed Spectrograph (NIRSpec) to study the cloud's chemical composition.
Astronomers are interested in determining how volatile chemicals survive the formation of stars and planets. Volatile chemicals are compounds that take off, go directly from a state of accumulation of a solid to a gas, at a relatively low temperature - including water and carbon monoxide. They will then compare their findings to the amounts found in protoplanetary disks of similar stars.
