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Webb wows with incredible detail in actively forming star system, Lynds 483 (L483)

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At the centre is a thin vertical cloud known as Lynds 483 (L483) that is roughly shaped like an hourglass with irregular edges. The lower lobe is slightly cut off. The top lobe is seen in full, petering out at the top.

Webb wows with incredible detail in actively forming star system, Lynds 483 (L483)

High-resolution near-infrared light captured by the NASA/ESA/CSA 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 colour image.

At the centre is a thin vertical cloud known as Lynds 483 (L483) that is roughly shaped like an hourglass with irregular edges. The lower lobe is slightly cut off. The top lobe is seen in full, petering out at the top.
Shimmering ejections emitted by two actively forming stars make up Lynds 483 (L483). High-resolution near-infrared light captured by the NASA/ESA/CSA 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.
Credit: NASA, ESA, CSA, STScI

Over tens of thousands of years, the central protostars [1] 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.

Dust-encased stars

The two protostars responsible for this scene are at the centre 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, the 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.

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 catalogues 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 catalogues 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.

In the centre is a thin vertical cloud known as Lynds 483 (L483) that is roughly shaped like an hourglass with irregular edges. At the top right is a scale bar labeled 0.1 light-years. The length of the scale bar is about one fifth of the total image. At the bottom left are compass arrows indicating the orientation of the image on the sky. The east arrow points toward 12 o’clock. The north arrow points in the 3 o’clock direction. Below the image is a colour key showing which NIRCam filters were used to create the image and which visible-light colour is assigned to each filter. From left to right: F115W and F200W are blue, F335M is green, F444W is yellow, F470N is red.
This image of protostar Lynds 483 (L483), captured by the NASA/ESA/CSA James Webb Space Telescope’s NIRCam (Near-Infrared Camera), shows compass arrows, scale bar, and colour key for reference. The north and east compass arrows show the orientation of the image on the sky. Note that the relationship between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above).
The scale bar is labelled in light-years, which is the distance that light travels in one Earth-year. (It takes 0.1 years for light to travel a distance equal to the length of the scale bar.) One light-year is equal to 9.46 trillion kilometres. This image shows invisible near-infrared wavelengths of light that have been translated into visible-light colours. The colour key shows which NIRCam filters were used when collecting the light. The colour of each filter name is the visible light colour used to represent the infrared light that passes through that filter.
Credit: NASA, ESA, CSA, STScI

Notes

[1] A protostar is a collection of interstellar gas and dust whose gravitational pull is causing it to collapse on itself and form a star.

Press release from ESA Webb.

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Hubble sees FS Tau B, likely in the process of becoming a T Tauri star

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FS Tau B A bright point of light shines near center-right with diffraction spikes, surrounded by glowing clouds against black space. A blue jet of material extends roughly throughout the center of the image, partially obscured by the clouds.

Hubble sees FS Tau B, likely in the process of becoming a T Tauri star

Jets emerge from the cocoon of a newly forming star to blast across space, slicing through the gas and dust of a shining nebula, in this new image from the NASA/ESA Hubble Space Telescope.

A bright point of light shines near center-right with diffraction spikes, surrounded by glowing clouds against black space. A blue jet of material extends roughly throughout the center of the image, partially obscured by the clouds.
FS Tau is a multi-star system made up of FS Tau A, the bright star-like object near the middle of the image, and FS Tau B (Haro 6-5B), the bright object to the far right that is partially obscured by a dark, vertical lane of dust. The young objects are surrounded by softly illuminated gas and dust of this stellar nursery. The system is only about 2.8 million years old, very young for a star system. Our Sun, by contrast, is about 4.6 billion years old.
FS Tau B is a newly forming star, or protostar, and is surrounded by a protoplanetary disc, a pancake-shaped collection of dust and gas leftover from the formation of the star that will eventually coalesce into planets. The thick dust lane, seen nearly edge-on, separates what are thought to be the illuminated surfaces of the disc.
FS Tau B is likely in the process of becoming a T Tauri star, a type of young variable star that hasn’t begun nuclear fusion yet but is beginning to evolve into a hydrogen-fueled star similar to our Sun. Protostars shine with the heat energy released as the gas clouds from which they are forming collapse, and from the accretion of material from nearby gas and dust. Variable stars are a class of star whose brightness changes noticeably over time.
FS Tau A is itself a T Tauri binary system, consisting of two stars orbiting each other.
Protostars are known to eject fast-moving, column-like streams of energised material called jets, and FS Tau B provides a striking example of this phenomenon. The protostar is the source of an unusual asymmetric, double-sided jet, visible here in blue. Its asymmetrical structure may be because mass is being expelled from the object at different rates.
FS Tau B is also classified as a Herbig-Haro object. Herbig–Haro objects form when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds, creating bright patches of nebulosity.
FS Tau is part of the Taurus-Auriga region, a collection of dark molecular clouds that are home to numerous newly forming and young stars, roughly 450 light-years away in the constellations of Taurus and Auriga. Hubble has previously observed this region, whose star-forming activity makes it a compelling target for astronomers. Hubble made these observations as part of an investigation of edge-on dust discs around young stellar objects.
Credit: NASA, ESA, K. Stapelfeldt (NASA JPL), G. Kober (NASA/Catholic University of America)

FS Tau is a multi-star system made up of FS Tau A, the bright star-like object near the middle of the image, and FS Tau B (Haro 6-5B), the bright object to the far right that is partially obscured by a dark, vertical lane of dust. These young objects are surrounded by the softly illuminated gas and dust of this stellar nursery. The system is only about 2.8 million years old, very young for a star system. Our Sun, by contrast, is about 4.6 billion years old.

FS Tau B is a newly forming star, or protostar, and is surrounded by a protoplanetary disc, a pancake-shaped collection of dust and gas left over from the formation of the star that will eventually coalesce into planets. The thick dust lane, seen nearly edge-on, separates what are thought to be the illuminated surfaces of the disc.

FS Tau B is likely in the process of becoming a T Tauri star, a type of young variable star that hasn’t begun nuclear fusion yet but is beginning to evolve into a hydrogen-fueled star similar to our Sun. Protostars shine with the heat energy released as the gas clouds from which they are forming collapse, and from the accretion of material from nearby gas and dust. Variable stars are a class of star whose brightness changes noticeably over time.

FS Tau A is itself a T Tauri binary system, consisting of two stars orbiting each other.

Protostars are known to eject fast-moving, column-like streams of energised material called jets, and FS Tau B provides a striking example of this phenomenon. The protostar is the source of an unusual asymmetric, double-sided jet, visible here in blue. Its asymmetrical structure may be because mass is being expelled from the object at different rates.

FS Tau B is also classified as a Herbig-Haro object. Herbig–Haro objects form when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds, creating bright patches of nebulosity.

FS Tau is part of the Taurus-Auriga region, a collection of dark molecular clouds that are home to numerous newly forming and young stars, roughly 450 light-years away in the constellations of Taurus and Auriga. Hubble has previously observed this region, whose star-forming activity makes it a compelling target for astronomers. Hubble made these observations as part of an investigation of edge-on dust discs around young stellar objects.

Press release from ESA Hubble.

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Webb finds complex organic molecules in early-stage protostars

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A region of a molecular cloud. The cloud is dense and bright close to the top of the image, like rolling clouds, and grows darker and more wispy towards the bottom and in the top corner. One bright star, and several dimmer stars, are visible as light spots among the clouds. The image is a single exposure which has been assigned an orange colour for visibility.

Cheers! Webb finds complex organic molecules (COMs), such as ethanol and other icy ingredients for worlds, in early-stage protostars

An international team of astronomers using the NASA/ESA/CSA James Webb Space Telescope have discovered a variety of molecules, ranging from relatively simple ones like methane to complex compounds like acetic acid and ethanol, in early-stage protostars where planets have not yet formed. These are key ingredients for making potentially habitable worlds.

The presence of complex organic molecules (COMs) [1] in the solid phase in protostars was first predicted decades ago from laboratory experiments, and tentative detections of these molecules have been made by other space telescopes. This includes Webb’s Early Release Science Ice Age programme, which discovered diverse ices in the darkest, coldest regions of a molecular cloud measured to date.

A region of a molecular cloud. The cloud is dense and bright close to the top of the image, like rolling clouds, and grows darker and more wispy towards the bottom and in the top corner. One bright star, and several dimmer stars, are visible as light spots among the clouds. The image is a single exposure which has been assigned an orange colour for visibility.
This image was taken by Webb’s Mid-InfraRed Instrument (MIRI) of a region parallel to the massive protostar known as IRAS23385.
IRAS 2A and IRAS23385 (not visible in this image) were targets for a recent research effort by an international team of astronomers that used Webb to discover that the key ingredients for making potentially habitable worlds are present in early-stage protostars, where planets have not yet formed.
With MIRI’s unprecedented spectral resolution and sensitivity, the JOYS+ (James Webb Observations of Young ProtoStars) programme individually identified organic molecules that have been confirmed to be present in interstellar ices. This includes the robust detection of acetaldehyde, ethanol, methyl formate, and likely acetic acid, in the solid phase.
Credit: ESA/Webb, NASA, CSA, W. Rocha et al. (Leiden University)

Now, with the unprecedented spectral resolution and sensitivity of Webb’s Mid-InfraRed Instrument (MIRI), as part of the JOYS+ (James Webb Observations of Young ProtoStars) programme, these COMs have been individually identified and confirmed to be present in the interstellar ices. This includes the robust detection of acetaldehyde, ethanol (what we call alcohol), methyl formate, and likely acetic acid (the acid in vinegar), in the solid phase.

“This finding contributes to one of the long-standing questions in astrochemistry,” said team leader Will Rocha of Leiden University in the Netherlands. “What is the origin of COMs in space? Are they made in the gas phase or in ices? The detection of COMs in ices suggests that solid-phase chemical reactions on the surfaces of cold dust grains can build complex kinds of molecules.”

An international team of scientists using the NASA/ESA/CSA James Webb Space Telescope has identified a wealth of complex, carbon-containing (organic) molecules surrounding two protostars. This graphic shows the spectrum of one of the two protostars, IRAS 2A. It includes the fingerprints of acetaldehyde, ethanol, methylformate, and likely acetic acid, in the solid phase. These and other molecules detected there by Webb represent key ingredients for making potentially habitable worlds.Credit: NASA, ESA, CSA, L. Hustak (STScI)
An international team of scientists using the NASA/ESA/CSA James Webb Space Telescope has identified a wealth of complex, carbon-containing (organic) molecules surrounding two protostars. This graphic shows the spectrum of one of the two protostars, IRAS 2A. It includes the fingerprints of acetaldehyde, ethanol, methylformate, and likely acetic acid, in the solid phase. These and other molecules detected there by Webb represent key ingredients for making potentially habitable worlds.
Credit: NASA, ESA, CSA, L. Hustak (STScI)

As several COMs, including those detected in the solid phase in this research, were previously detected in the warm gas phase, it is now believed that they originate from the sublimation of ices. Sublimation is to change directly from a solid to a gas without becoming a liquid. Therefore, detecting COMs in ices makes astronomers hopeful about developing an improved understanding of the origins of other even larger molecules in space.

Harold Linnartz [2] led the Laboratory for Astrophysics in Leiden over many years and coordinated the measurements of the data used in this study. Ewine van Dishoeck of Leiden University, one of the coordinators of the JOYS+ programme, shared,

“Harold was particularly happy that in the COM assignments lab work could play an important role as it has been a long time getting here.”

Scientists are also keen to explore to what extent these COMs are transported to planets at much later stages in the evolution of the protostar. COMs in ices are transported more efficiently into planet-forming discs than gas from clouds. These icy COMs can therefore be inherited by comets and asteroids which in turn may collide with planets in formation. In that scenario COMs can be delivered to those planets, potentially providing the ingredients for life to flourish.

The science team also detected simpler molecules, including methane, formic acid (which makes the sting of ants painful), sulphur dioxide, and formaldehyde. Sulphur dioxide in particular allows the team to investigate the sulphur budget available in protostars. In addition, it is of prebiotic interest because existing research suggests that sulphur-containing compounds played an important role in driving metabolic reactions on the primitive Earth. Negative ions were also detected [3]; they form part of salts that are crucial for developing further chemical complexity at higher temperatures. This indicates that the ices may be much more complex and require further research.

Of particular interest is that one of the sources investigated, IRAS 2A, is characterised as a low-mass protostar. IRAS 2A may therefore have similarities with the primordial stages of our own Solar System. If that is the case, the chemical species identified in this protostar may have been present in the first stages of development of our Solar System and were later delivered to the primitive Earth.

All of these molecules can become part of comets and asteroids and eventually new planetary systems when the icy material is transported inward to the planet-forming discs as the protostellar system evolves,” said van Dishoeck. “We look forward to following this astrochemical trail step by step with more Webb data in the coming years.”

Other recent work by Pooneh Nazari of Leiden Observatory also raises astronomers’ hopes for finding more complexity in ices, following the tentative detections of methyl cyanide and ethyl cyanide from Webb NIRSpec data. Nazari says,

“It is impressive how Webb now allows us to further probe the ice chemistry down to the level of cyanides, important ingredients in prebiotic chemistry.”

 

Notes

[1] A molecule is a particle made up of two or more atoms that are held together by chemical bonds. A complex organic molecule is a molecule with multiple carbon atoms.

[2] These results are dedicated to team member Professor Harold Linnartz, who unexpectedly passed away in December 2023, shortly after the acceptance of this paper. Linnartz made significant contributions to the study of gaseous and icy molecules in space. He was the Director of the Leiden Laboratory for Astrophysics and many of the ice-phase spectra of simple and complex molecules used in this research were collected by students under his supervision. Linnartz was thrilled with the quality of the Webb data and the significance of these results for astrochemistry.

[3] An ion is an atom or molecule that has an overall electrical charge, resulting from an excess or deficit in the number of negative electrons compared to the number of positive protons in the ion. A negative ion is an ion with a net negative charge (so a surplus of electrons).

 

Press release from ESA Webb.

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Webb reveals new features from Sagittarius C, in the heart of the Milky Way

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[Image description: In a field crowded with stars, a funnel-shaped region of space appears darker than its surroundings with fewer stars. It is wider at the top edge of the image, narrowing towards the bottom. Toward the narrow end of this dark region a small clump of red and white appears to shoot out streamers upward and left. A large, bright cyan-colored area surrounds the lower portion of the funnel-shaped dark area, forming a rough U shape. The cyan-coloured area has needle-like, linear structures and becomes more diffuse in the center of the image. The right side of the image is dominated by clouds of orange and red, with a purple haze.]

Webb reveals new features from Sagittarius C, in the heart of the Milky Way

The latest image from the NASA/ESA/CSA James Webb Space Telescope shows a portion of the dense centre of our galaxy in unprecedented detail, including never-before-seen features astronomers have yet to explain. The star-forming region, named Sagittarius C (Sgr C), is about 300 light-years from the Milky Way’s central supermassive black hole, Sagittarius A*.

[Image description: In a field crowded with stars, a funnel-shaped region of space appears darker than its surroundings with fewer stars. It is wider at the top edge of the image, narrowing towards the bottom. Toward the narrow end of this dark region a small clump of red and white appears to shoot out streamers upward and left. A large, bright cyan-colored area surrounds the lower portion of the funnel-shaped dark area, forming a rough U shape. The cyan-coloured area has needle-like, linear structures and becomes more diffuse in the center of the image. The right side of the image is dominated by clouds of orange and red, with a purple haze.]
The full view of the NASA/ESA/CSA James Webb Space Telescope’s NIRCam (Near-Infrared Camera) instrument reveals a 50 light-years-wide portion of the Milky Way’s dense centre. An estimated 500,000 stars shine in this image of the Sagittarius C (Sgr C) region, along with some as-yet unidentified features.
A vast region of ionised hydrogen, shown in cyan, wraps around an infrared-dark cloud, which is so dense that it blocks the light from distant stars behind it. Intriguing needle-like structures in the ionised hydrogen emission lack any uniform orientation. Researchers note the surprising extent of the ionised region, covering about 25 light-years.
A cluster of protostars – stars that are still forming and gaining mass – are producing outflows that glow like a bonfire at the base of the large infrared-dark cloud, indicating that they are emerging from the cloud’s protective cocoon and will soon join the ranks of the more mature stars around them. Smaller infrared-dark clouds dot the scene, appearing like holes in the starfield.
Researchers say they have only begun to dig into the wealth of unprecedented high-resolution data that Webb has provided on this region, and many features bear detailed study. This includes the rose-coloured clouds on the right side of the image, which have never been seen in such detail.
Credit: NASA, ESA, CSA, STScI, S. Crowe (UVA)
Amid the estimated 500,000 stars in the image is a cluster of protostars – stars that are still forming and gaining mass – producing outflows that glow like a bonfire in the midst of an infrared-dark cloud. At the heart of this young cluster is a previously known, massive protostar over 30 times the mass of our Sun. The cloud the protostars are emerging from is so dense that the light from stars behind it cannot reach Webb, making it appear less crowded when in fact it is one of the most densely packed areas of the image. Smaller infrared-dark clouds dot the image, looking like holes in the starfield. That’s where future stars are forming.

Webb’s NIRCam (Near-Infrared Camera) instrument also captured large-scale emission from ionised hydrogen surrounding the lower side of the dark cloud, shown cyan-coloured in the image. Typically, this is the result of energetic photons being emitted by young massive stars, but the vast extent of the region shown by Webb is something of a surprise that bears further investigation. Another feature of the region that scientists plans to examine further is the needle-like structures in the ionised hydrogen, which appear oriented chaotically in many directions.

Around 25,000 light-years from Earth, the galactic centre is close enough to study individual stars with the Webb telescope, allowing astronomers to gather unprecedented information on how stars form, and how this process may depend on the cosmic environment, especially compared to other regions of the galaxy. For example, are more massive stars formed in the centre of the Milky Way, as opposed to the edges of its spiral arms?

Webb Sagittarius C[Image description: In a field crowded with stars, a funnel-shaped region of space appears darker than its surroundings with fewer stars. It is wider at the top edge of the image, narrowing towards the bottom. Toward the narrow end of this dark region a small clump of red and white appears to shoot out streamers upward and left. A large, bright cyan-coloured area surrounds the lower portion of the funnel-shaped dark area, forming a rough U shape. The cyan-coloured area has needle-like, linear structures and becomes more diffuse in the center of the image. The right side of the image is dominated by clouds of orange and red, with a purple haze.]
This image of Sagittarius C (Sgr), captured by Webb’s Near-Infrared Camera (NIRCam), shows compass arrows, scale bar, and colour key for reference.
The north and east compass arrows show the orientation of the image on the sky. Note that the relationship between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above).
The scale bar is labelled in light-years, which is the distance that light travels in one Earth-year. (It takes 3 years for light to travel a distance equal to the length of the scale bar.) One light-year is equal to about 5.88 trillion miles or 9.46 trillion kilometres. The field of view shown in this image is approximately 50 light-years long.
This image shows invisible near-infrared wavelengths of light that have been translated into visible-light colours. The colour key shows which NIRCam filters were used when collecting the light. The colour of each filter name is the visible light colour used to represent the infrared light that passes through that filter.
Credit: NASA, ESA, CSA, STScI, S. Crowe (UVA)
Press release from ESA Webb.

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