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Webb’s latest mid-infrared image reveals the formation of a protostar, highlighted by color variations that detail its dynamic interactions with the surrounding molecular cloud.

NASA‘c James Webb Space Telescope celebrates US Independence Day with an observation of the protostar hidden in the dark molecular cloud L1527 in mid-infrared light as it evolves. This vivid new view highlights the behavior of this young object and traces the varying concentrations of gas and dust around the protostar.

L1527, shown in this MIRI (Mid Infrared Instrument) image on NASA’s James Webb Space Telescope, is a molecular cloud that contains a protostar. It is located about 460 light years from Earth in the constellation Taurus. The more diffuse blue light and filamentary structures in the image come from organic compounds known as polycyclic aromatic hydrocarbons (PAHs), while the red in the center of this image is an energized, thick layer of gas and dust that surrounds the protostar. The region in between, shown in white, is a mixture of PAHs, ionized gas and other molecules. Courtesy: NASA, ESA, CSA, STScI

The Webb Space Telescope captured celestial fireworks around the forming star

Space seems to come alive with a crackling explosion of pyrotechnics in this new image from NASA’s James Webb Space Telescope. Imaged with Webb’s MIRI (Mid-Infrared Instrument), this fiery hourglass marks the scene of a very young object in the process of becoming a star. A central protostar grows in the mouth of the hourglass, accreting material from a thin protoplanetary disk, seen laterally as a dark line.

Insights into protostellar evolution

The protostar, a relatively young object of about 100,000 years old, is still surrounded by its parent molecular cloud, or large region of gas and dust. Webb’s previous NIRCam (Near Infrared Camera) observation of L1527 allowed us to peer into this region and revealed this molecular cloud and protostar in opaque, vivid colors.

Dynamic outflows and molecular impact

Both NIRCam and MIRI show the effects of outflows that radiate in opposite directions along the protostar’s spin axis as the object consumes gas and dust from the surrounding cloud. These outflows take the form of arcing shocks to the surrounding molecular cloud that appear as filamentary structures throughout. They are also responsible for carving out the bright hourglass structure within the molecular cloud, as they energize or excite the surrounding matter and cause the regions above and below it to glow. This creates an effect reminiscent of fireworks lighting up a cloudy night sky. Unlike NIRCam, however, which mostly shows the light that is reflected from dust, MIRI provides a look at how these outflows affect the thickest dust and gases in the region.

The areas colored here in blue, which cover most of the hourglass, show mostly carbon molecules known as polycyclic aromatic hydrocarbons. The protostar itself and the dense blanket of dust and mixed gas that surrounds it are shown in red. The spark-like red extensions are an artifact of the telescope’s optics (see image below).

This illustration demonstrates the science behind Webb’s diffraction peak patterns, showing how diffraction peaks occur, the influence of the primary mirror and supports, and the contribution of each to Webb’s diffraction peaks. Courtesy: NASA, ESA, CSA, Leah Hustak (STScI), Joseph DePasquale (STScI)

In between, MIRI reveals a white region just above and below the protostar that doesn’t show up as strongly in the NIRCam view. This region is a mixture of hydrocarbons, ionized neon, and dense dust, indicating that the protostar is pushing this matter quite far away from itself as it indiscriminately consumes material from its disk.

An evolving protostar and its future

As the protostar continues to age and release jets of energy, it will engulf, destroy, and push away much of this molecular cloud, and many of the structures we see here will begin to fade. Eventually, once it has finished gathering mass, this impressive performance will end and the star itself will become more apparent even to our visible-light telescopes.

This image of the L1527 nebula taken by the Webb Mid-Infrared Instrument (MIRI) shows compass hands, a scale bar, and a color key for reference.
The north and east arrows on the compass indicate the orientation of the image on the sky. Note that the relationship between north and east in the sky (as seen below) is reversed relative to the direction arrows on the earth map (as seen above).
The scale bar is indicated in astronomical units (AU), which is the average distance between Earth and the Sun, or 93 million miles (150 million kilometers).
This image shows invisible mid-infrared wavelengths of light that are translated into visible light colors. The color key indicates which MIRI filters were used to collect the light. The color of each filter’s name is the visible light color used to represent the infrared light that passes through that filter.
Courtesy: NASA, ESA, CSA, STScI

The combination of analyzes from both the near-infrared and mid-infrared views reveals the overall behavior of this system, including how the central protostar affects the surrounding region. Other stars in Taurus, the star-forming region where L1527 is located, form in exactly this way, which can disrupt other molecular clouds and either prevent new stars from forming or catalyze their development.

The James Webb Space Telescope (JWST), often hailed as the successor to the Hubble Space Telescope, is a large space observatory optimized for infrared wavelengths. This allows it to look further back in time than any other telescope, watching the formation of the first galaxies and stars. Launched on December 25, 2021, JWST provides unprecedented resolution and sensitivity, allowing astronomers to study every phase of the cosmic history of our universe. Its main capabilities include studying the atmospheres of exoplanets, observing distant galaxies and studying star formation in detail.