Free Astronomy Magazine September-October 2024

34 SEPTEMBER-OCTOBER 2024 Alignment of bipolar jets confirms star formation theories by NASA/ESA/CSA Bethany Downer Christine Pulliam F or the first time, a phenomenon astronomers have long hoped to directly image has been cap- tured by NASA’s James Webb Space Telescope’s Near-Infrared Camera (NIRCam). In this stunning image of the Serpens Nebula, the discovery lies in the northern area (seen at the upper left) of this young, nearby star-forming region. Astronomers found an intriguing group of proto- stellar outflows, formed when jets of gas spewing from newborn stars collide with nearby gas and dust at high speeds. Typically these ob- jects have varied orientations within one region. Here, however, they are slanted in the same direction, to the same degree, like sleet pouring down during a storm. The discovery of these aligned ob- jects, made possible due to Webb’s exquisite spatial resolution and sensitivity in near-infrared wave- lengths, is providing information into the fundamentals of how stars are born. “Astronomers have long assumed that as clouds collapse to form stars, the stars will tend to spin in the same direction,” said principal investigator Klaus Pontoppidan, of NASA’s Jet Propulsion Laboratory in Pasadena, California. “However, this has not been seen so directly before. These aligned, elongated structures are a historical record of the funda- mental way that stars are born.” So just how does the alignment of the stellar jets relate to the rotation of the star? As an interstellar gas cloud crashes in on itself to form a star, it spins more rapidly. The only way for the gas to continue moving inward is for some of the spin (known as angular momentum) to be removed. A disk of material forms around the young star to trans-