Is it a roman candle? A double ended light saber? A blowtorch? The gases erupting from a volcanically growing monster star captured by NASA’s James Webb Space Telescope have inspired many vivid comparisons. Stretching across 8 light-years, the length of the huge stellar eruption is approximately twice the distance between our Sun and the nearest star. A rare find, according to the researchers.
“I was really surprised at the order, symmetry, and size of the jet when we first looked at it,” said astronomer Jonathan Tan of Chalmers, and the University of Virginia, USA.
This particular stellar jet, is located in a nebula known as Sharpless 2-284 (Sh2-284 for short). The central star, weighing as much as ten of our Suns, is located 15,000 light-years away in the outer reaches of our galaxy.
This unique class of stellar fireworks are highly collimated jets of plasma shooting out from newly forming stars. Such jetted outflows are a star’s spectacular “birth announcement” to the universe. Some of the infalling gas building up around the central star is blasted along the star’s spin axis, likely under the influence of magnetic fields.
The bigger the star, the bigger the jets
Today, while hundreds of protostellar jets have been observed, these are mainly from low-mass stars. The new discovery offers evidence that stellar jets must scale up with the mass of the newly born star powering them. The more massive the stellar engine propelling the plasma, the larger the gusher’s size.
The jet’s detailed filamentary structure, captured by Webb’s crisp resolution in infrared light, is evidence the jet is plowing into interstellar dust and gas. This creates separate knots, bow shocks, and linear chains.
The tips of the jet, lying in opposite directions, encapsulate the history of the star’s formation. “Originally the material was close into the star, but over 100,000 years the tips were propagating out, and then the stuff behind is a younger outflow,” said Jonathan Ta, co-author of the study in The Astrophysical Journal. Lead author is Yu Cheng of the National Astronomical Observatory of Japan.
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The image shows invisible near-infrared wavelengths of light that have been translated into visible-light colors. It is a composite of separate exposures acquired by James Webb Space Telescopes NIRCam instrument. Several filters were used to sample specific wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter.
This text is based on the Nasa press release: NASA’s Webb Observes Immense Stellar Jet on Outskirts of Our Milky Way
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