High-resolution near-infrared light captured by NASA’s James Webb Space Telescope shows extraordinary new detail and structure in Lynds 483 (L483). Two actively forming stars are responsible for the shimmering ejections of gas and dust that gleam in orange, blue, and purple in this representative color image.
Over tens of thousands of years,
the central protostars have periodically ejected some of the gas and
dust, spewing it out as tight, fast jets and slightly slower outflows that
“trip” across space. When more recent ejections hit older ones, the material
can crumple and twirl based on the densities of what is colliding. Over time,
chemical reactions within these ejections and the surrounding cloud have
produced a range of molecules, like carbon monoxide, methanol, and several
other organic compounds.
Image A: Actively Forming Star
System Lynds 483 (NIRCam Image)
Shimmering ejections emitted by two actively forming
stars make up Lynds 483 (L483). High-resolution near-infrared light captured by
NASA’s James Webb Space Telescope shows incredible new detail and structure
within these lobes, including asymmetrical lines that appear to run into one
another. L483 is 650 light-years away in the constellation Serpens.
NASA, ESA, CSA, STScI
Dust-Encased Stars
The two protostars responsible for
this scene are at the center of the hourglass shape, in an opaque horizontal
disk of cold gas and dust that fits within a single pixel. Much farther out,
above and below the flattened disk where dust is thinner, the bright light from
the stars shines through the gas and dust, forming large semi-transparent
orange cones.
It’s equally important to notice
where the stars’ light is blocked — look for the exceptionally dark, wide
V-shapes offset by 90 degrees from the orange cones. These areas may look like
there is no material, but it’s actually where the surrounding dust is the
densest, and little starlight penetrates it. If you look carefully at these
areas, Webb’s sensitive NIRCam (Near-Infrared Camera) has picked up distant
stars as muted orange pinpoints behind this dust. Where the view is free of
obscuring dust, stars shine brightly in white and blue.
Unraveling the Stars’ Ejections
Some of the stars’ jets and
outflows have wound up twisted or warped. To find examples, look toward the top
right edge where there’s a prominent orange arc. This is a shock front, where
the stars’ ejections were slowed by existing, denser material.
Now, look a little lower, where
orange meets pink. Here, material looks like a tangled mess. These are new,
incredibly fine details Webb has revealed, and will require detailed study to
explain.
Turn to the lower half. Here, the
gas and dust appear thicker. Zoom in to find tiny light purple pillars. They
point toward the central stars’ nonstop winds, and formed because the material
within them is dense enough that it hasn’t yet been blown away. L483 is too
large to fit in a single Webb snapshot, and this image was taken to fully
capture the upper section and outflows, which is why the lower section is only
partially shown. (See a larger view observed by NASA's retired Spitzer Space
Telescope.)
All the symmetries and asymmetries
in these clouds may eventually be explained as researchers reconstruct the
history of the stars’ ejections, in part by updating models to produce the same
effects. Astronomers will also eventually calculate how much material the stars
have expelled, which molecules were created when material smashed together, and
how dense each area is.
Millions of years from now, when
the stars are finished forming, they may each be about the mass of our Sun.
Their outflows will have cleared the area — sweeping away these
semi-transparent ejections. All that may remain is a tiny disk of gas and dust
where planets may eventually form.
L483 is named for American astronomer Beverly T. Lynds, who published extensive catalogs of “dark” and “bright” nebulae in the early 1960s. She did this by carefully examining photographic plates (which preceded film) of the first Palomar Observatory Sky Survey, accurately recording each object’s coordinates and characteristics. These catalogs provided astronomers with detailed maps of dense dust clouds where stars form — critical resources for the astronomical community decades before the first digital files became available and access to the internet was widespread.
Source: NASA Webb Wows With Incredible Detail in Actively Forming Star System - NASA Science
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