NASA’s James Webb Space Telescope has captured a jaw-dropping sight: a massive jet of glowing gas blasting out from a newborn star like a fiery blowtorch. This stellar eruption stretches 8 light-years across, which is twice the distance between our Sun and Alpha Centauri, our closest neighboring star system.
The jet, located in the Sharpless 2-284 nebula, is rare in both size and power. Racing through space at hundreds of thousands of miles per hour, it looks uncannily like a double-bladed lightsaber straight out of Star Wars.
At the heart of this spectacle is a protostar, a baby star still forming, about ten times heavier than our Sun, sitting 15,000 light-years away on the edge of the Milky Way. It’s a galactic birth announcement, written in plasma and speed.
Lead author Yu Cheng of the National Astronomical Observatory of Japan said, “The Webb discovery was serendipitous. We didn’t really know there was a massive star with this kind of super-jet out there before the observation. Such a spectacular outflow of molecular hydrogen from a massive star is rare in other regions of our galaxy.”
When a star is being born, it doesn’t arrive quietly; it shoots out blazing jets of plasma in opposite directions, like cosmic fireworks. These highly focused outflows, called protostellar jets, are nature’s way of saying, ‘A new star is here!’.
As gas falls into the star, some of it gets blasted out along the star’s spin axis, likely guided by magnetic fields. These jets are narrow and powerful, and they help scientists understand the star’s growth, energy, and environment.
Most of the jets we’ve seen come from low-mass stars, but each one offers clues about how stars form and evolve. By studying their shape, speed, and lifespan, researchers can fine-tune models of stellar birth.
Co-author Jonathan Tan of the University of Virginia in Charlottesville and Chalmers University of Technology in Gothenburg, Sweden said, “I was really surprised at the order, symmetry, and size of the jet when we first looked at it.”
Scientists found that the jet’s scale grows with the mass of the star powering it. In other words, the bigger the baby star, the more dramatic its plasma outburst.
Captured in stunning infrared detail, the jet shows a filamentary structure, a sign that it’s crashing into clouds of interstellar dust and gas. This collision creates knots, bow shocks, and linear chains, like ripples from a cosmic splash.
At the far ends of the jet, stretching in opposite directions, lie clues to the star’s past. These tips act like timestamps, preserving the history of the star’s formation as it grew and evolved.
“Originally, the material was close to the star, but over 100,000 years, the tips were propagating out, and then the stuff behind is a younger outflow,” said Tan.
The proto-cluster hosting the massive jet in Sh2-284 sits far out on the fringes of the Milky Way, nearly twice as far from the galactic center as our Sun. It’s a quiet, remote region where hundreds of stars are still forming, like cosmic seedlings in a sparse field.
Because it’s so far out, this region has low metallicity, meaning its stars contain very few elements heavier than hydrogen and helium. That’s typical of the early universe, before generations of stars enriched space with metals through supernovae and stellar winds.
In this way, Sh2-284 acts as a local time capsule, giving scientists a rare glimpse into how stars may have formed in the universe’s youth.
Cheng said, “Massive stars, like the one found inside this cluster, have significant influences on the evolution of galaxies. Our discovery is shedding light on the formation mechanism of massive stars in low metallicity environments, so we can use this massive star as a laboratory to study what was going on in earlier cosmic history.”
Tan said, “Webb’s new images are telling us that the formation of massive stars in such environments could proceed via a relatively stable disk around the star that is expected in theoretical models of star formation known as core accretion.”
“Once we found a massive star launching these jets, we realized we could use the Webb observations to test theories of massive star formation. We developed new theoretical core accretion models that were fit to the data, to basically tell us what kind of star is in the center. These models imply that the star is about 10 times the mass of the Sun and is still growing and has been powering this outflow.”
For over 30 years, astronomers have debated how massive stars form. One idea, called competitive accretion, suggests stars grow through a chaotic process, pulling in gas from all directions, causing their disks to wobble and their jets to twist.
But new observations from the James Webb Space Telescope tell a different story. Scientists saw jets shooting out in perfectly opposite directions, like a straight arrow. That means the disk around the star stayed steady, supporting a calmer theory called core accretion, where stars grow from a stable, rotating disk.
And there’s more: in this quiet corner of the Milky Way, where stars are still forming, researchers found another dense core that might be the next massive star in the making, spotted by the Atacama Large Millimeter Array in Chile.
Journal Reference:
- Yu Cheng, Jonathan C. Tan, Morten Andersen, Rubén Fedriani, Yichen Zhang, Massimo Robberto, Zhi-Yun Li, and Kei E. I. Tanaka. LZ-STAR Survey: Low-metallicity Star Formation Survey of Sh2-284. I. Ordered Massive Star Formation in the Outer Galaxy. The Astrophysical Journal. DOI 10.3847/1538-4357/addf4b
