Chandra X-Ray Observatory Captures Breathtaking New Images

 

The images feature data from the Smithsonian Astrophysical Observatory along with a host of other NASA telescopes including the James Webb Space Telescope, Hubble Space Telescope and more.

Top row:

N79 is a giant region of star formation in the Large Magellanic Cloud, a small satellite neighbor galaxy to the Milky Way. Chandra sees the hot gas created by young stars, which helps astronomers better understand how stars like our Sun formed billions of years ago. [X-rays from Chandra (purple) and infrared data from Webb (blue, grey and gold)]

NGC 2146 is a spiral galaxy with one of its dusty arms obscuring the view of its center from Earth.. X-rays from Chandra reveal double star systems and hot gas being expelled from the galaxy by supernova explosions and strong winds from giant stars. [X-rays from Chandra (pink and purple), optical data from Hubble and the Las Cumbres Observatory in Chile and infrared data from NSF’s Kitt Peak (red, green and blue)]

IC 348 is a star-forming region in our Milky Way galaxy. The wispy structures that dominate the image are interstellar material that reflects light from the cluster’s stars. The point-like sources in Chandra’s X-ray data are young stars forming in the cluster. [X-rays from Chandra (red, green and blue) and Webb infrared data (pink, orange and purple)]

Middle row:

M83, a spiral galaxy similar to the Milky Way, is oriented face-on toward Earth, providing an unobstructed view of its entire structure that is often not possible with galaxies viewed atdifferent angles. Chandra has detected the explosions of stars, or supernovas, and their aftermath across M83. [X-rays from Chandra (red, green and blue) with ground-based optical data (pink, gold and gray)].

M82 is a so-called starburst galaxy where stars are forming at rates tens to hundreds of times higher than normal galaxies. Chandra sees supernovas that produce expanding bubbles of multimillion-degree gas that extend for millions of light-years away from the galaxy's disk. [X-rays from Chandra (purple) with Hubble optical data (red, green, and blue)]

NGC 1068 is a relatively nearby spiral galaxy containing a black hole at its center that is twice as massive as the one in the Milky Ways. Chandra shows a million-mile-per-hour wind is being driven from NGC 1068’s black hole which lights (?) up the center of the galaxy in X-rays. [X-rays from Chandra (blue), radio data from NSF’s VLA radio data (pink), and optical data from Hubble and Webb (yellow, grey and gold)]

Bottom row:

NGC 346 is a young cluster home to thousands of newborn stars. The cluster’s most massive stars createpowerful winds and produce intense radiation. X-rays from Chandra reveal output from massive stars in the cluster and diffuse emission from a supernova remnant, the glowing debris of an exploded star. [X-rays from Chandra (purple) with optical and ultraviolet from Hubble blue, brown and gold)]

IC 1623 is a system where two galaxies are erging. As the galaxies collide, they trigger new bursts of star formation that glow intensely in certain kinds of light which is detected by Chandara and other telescopesThe merging galaxies may also be in the process of forming a supermassive black hole. [X-rays from Chandra (magenta) with Webb infrared data (red, gold and gray)]

Westerlund 1 is the biggest and closest “super” star cluster to Earth. Data from Chandra and other telescopes is helping astronomers delve deeper into this galactic factory where stars are being produced at extraordinarily high rates. Observations from Chandra have uncovered thousands of individual stars pumping out X-ray emission into the cluster. [X-rays from Chandra (pink, blue, purple and orange) with Webb infrared data (yellow, gold and blue) and Hubble optical data (cyan, grey and light yellow)]

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center, part of the Center for Astrophysics | Harvard & Smithsonian, controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

Source: Harvard-Smithsonian Center for Astrophysics (CfA)/News

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Media Contact:

Megan Watzke
Chandra X-Ray Observatory
mwatzke@cfa.harvard.edu

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Image Credits:

NGC 2146: X-ray: NASA/CXC/SAO; Optical: NASA/ESA/STScI and NOIRLab/NSF/AURA; Infrared: NSF/NOAO/KPNO; Image Processing: NASA/CXC/SAO/L. Frattare

IC 348: X-ray: NASA/CXC/SAO; Infrared: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/J. Major

M83: X-ray: NASA/CXC/SAO; Optical: NASA/ESA/AURA/STScI, Hubble Heritage Team, W. Blair (STScI/Johns Hopkins University) and R. O'Connell (University of Virginia); Image Processing: NASA/CXC/SAO/L. Frattare

M82: X-ray: NASA/CXC/SAO; Optical/IR: NASA/ESA/STScI; Image Processing: NASA/CXC/SAO/J. Major

NGC 1068: X-ray: NASA/CXC/SAO; Optical/IR: NASA/ESA/CSA/STScI (HST and JWST); Radio: NSF/NRAO/VLA; Image Processing: NASA/CXC/SAO/J. Schmidt and N. Wolk

NGC 346: X-ray: NASA/CXC/SAO; Optical/IR: NASA/ESA/CSA/STScI (HST and JWST); Radio: NSF/NRAO/VLA; Image Processing: NASA/CXC/SAO/J. Schmidt and N. Wolk

IC 1623: X-ray: NASA/CXC/SAO; IR: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/L. Frattare and J. Major

Westerlund 1: X-ray: NASA/CXC/SAO; Optical: NASA/ESA/STScI; IR: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/L. Frattare

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Colourful clouds of a nearby neighbour

SMC 13

An area of space that is filled with stars. Most of the stars are small, distant dots in orange colours; closer stars shine with a bright glow and four thin spikes around them. These closer stars appear in both bluish and reddish colours. Clouds from a nebula cover the left half of the scene, giving it a blue-greenish cast. More pieces of cloud drift over the black background of space on the right. Credit: ESA/Hubble & NASA, C. Murray

Say hello to one of the Milky Way’s neighbours! Today’s NASA/ESA Hubble Space Telescope Picture of the Week features a scene from one of the closest galaxies to the Milky Way, the Small Magellanic Cloud (SMC). The SMC is a dwarf galaxy located about 200 000 light-years away. Most of the galaxy resides in the constellation Tucana, but a small section crosses over into the neighbouring constellation Hydrus.

Thanks to its proximity, the SMC is one of only a few galaxies that can be seen from Earth without the help of a telescope or binoculars. For viewers in the southern hemisphere and some latitudes in the northern hemisphere, the SMC resembles a piece of the Milky Way that has broken off, though in reality it’s much farther away than any part of our own galaxy.

With its 2.4-metre ‘eye’ and sensitive instruments, Hubble’s view of the SMC is far more detailed and vivid than what humans can see. Researchers used Hubble’s Wide Field Camera 3 instrument to observe this scene through four different filters. Each filter admits different wavelengths of light, creating a multicoloured view of dust clouds drifting across a field of stars. Hubble’s view, however, is much more zoomed-in than our eyes, the better for it to observe very distant objects. This image captures a small region of the SMC near the centre of NGC 346, a star cluster that is home to dozens of massive young stars.

Source: ESA/Hubble/potw

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NASA's Webb Finds Planet-Forming Disks Lived Longer in Early Universe

Protoplanetary Disks in NGC 346 (NIRCam Image)
Credits/Image: NASA, ESA, CSA, STScI, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA)

Protoplanetary Disks in NGC 346 Spectra (NIRSpec)
Credits/Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)

NGC 346: Hubble and Webb Observations

Credits/Image: NASA, ESA, CSA, STScI, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA), Antonella Nota (ESA)

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NASA’s James Webb Space Telescope just solved a conundrum by proving a controversial finding made with the agency’s Hubble Space Telescope more than 20 years ago.

In 2003, Hubble provided evidence of a massive planet around a very old star, almost as old as the universe. Such stars possess only small amounts of heavier elements that are the building blocks of planets. This implied that some planet formation happened when our universe was very young, and those planets had time to form and grow big inside their primordial disks, even bigger than Jupiter. But how? This was puzzling.

To answer this question, researchers used Webb to study stars in a nearby galaxy that, much like the early universe, lacks large amounts of heavy elements. They found that not only do some stars there have planet-forming disks, but that those disks are longer-lived than those seen around young stars in our Milky Way galaxy.

“With Webb, we have a really strong confirmation of what we saw with Hubble, and we must rethink how we model planet formation and early evolution in the young universe,” said study leader Guido De Marchi of the European Space Research and Technology Centre in Noordwijk, Netherlands.

A Different Environment in Early Times

In the early universe, stars formed from mostly hydrogen and helium, and very few heavier elements such as carbon and iron, which came later through supernova explosions.

“Current models predict that with so few heavier elements, the disks around stars have a short lifetime, so short in fact that planets cannot grow big,” said the Webb study’s co-investigator Elena Sabbi, chief scientist for Gemini Observatory at the National Science Foundation’s NOIRLab in Tucson. "But Hubble did see those planets, so what if the models were not correct and disks could live longer?"

To test this idea, scientists trained Webb on the Small Magellanic Cloud, a dwarf galaxy that is one of the Milky Way’s nearest neighbors. In particular, they examined the massive, star-forming cluster NGC 346, which also has a relative lack of heavier elements. The cluster served as a nearby proxy for studying stellar environments with similar conditions in the early, distant universe.

Hubble observations of NGC 346 from the mid 2000s revealed many stars about 20 to 30 million years old that seemed to still have planet-forming disks around them. This went against the conventional belief that such disks would dissipate after 2 or 3 million years.

“The Hubble findings were controversial, going against not only empirical evidence in our galaxy but also against the current models,” said De Marchi. “This was intriguing, but without a way to obtain spectra of those stars, we could not really establish whether we were witnessing genuine accretion and the presence of disks, or just some artificial effects.”

Now, thanks to Webb’s sensitivity and resolution, scientists have the first-ever spectra of forming, Sun-like stars and their immediate environments in a nearby galaxy.

“We see that these stars are indeed surrounded by disks and are still in the process of gobbling material, even at the relatively old age of 20 or 30 million years,” said De Marchi. “This also implies that planets have more time to form and grow around these stars than in nearby star-forming regions in our own galaxy.”

A New Way of Thinking

This finding refutes previous theoretical predictions that when there are very few heavier elements in the gas around the disk, the star would very quickly blow away the disk. So the disk’s life would be very short, even less than a million years. But if a disk doesn't stay around the star long enough for the dust grains to stick together and pebbles to form and become the core of a planet, how can planets form?

The researchers explained that there could be two distinct mechanisms, or even a combination, for planet-forming disks to persist in environments scarce in heavier elements.

First, to be able to blow away the disk, the star applies radiation pressure. For this pressure to be effective, elements heavier than hydrogen and helium would have to reside in the gas. But the massive star cluster NGC 346 only has about ten percent of the heavier elements that are present in the chemical composition of our Sun. Perhaps it simply takes longer for a star in this cluster to disperse its disk.

The second possibility is that, for a Sun-like star to form when there are few heavier elements, it would have to start from a larger cloud of gas. A bigger gas cloud will produce a bigger disk. So there is more mass in the disk and therefore it would take longer to blow the disk away, even if the radiation pressure were working in the same way.

“With more matter around the stars, the accretion lasts for a longer time,” said Sabbi. "The disks take ten times longer to disappear. This has implications for how you form a planet, and the type of system architecture that you can have in these different environments. This is so exciting.”

The science team’s paper appears in the Dec. 16 issue of The Astrophysical Journal.

The James Webb Space Telescope is the world's premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt manages the telescope and mission operations. Lockheed Martin Space, based in Denver also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Source: Webb Space Telescope/News

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About This Release

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Media Contact:

Ann Jenkins
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

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Related Links and Documents

• The science paper by Guido De Marchi et al.

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NASA’s Webb Captures an Ethereal View of NGC 346

NGC 346 (MIRI Image)
Credits: Image: NASA, ESA, CSA, STScI, Nolan Habel (NASA-JPL)
Image Processing: Patrick Kavanagh (Maynooth University)

Release Images | Release Videos

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One of the greatest strengths of NASA’s James Webb Space Telescope is its ability to give astronomers detailed views of areas where new stars are being born. The latest example, showcased here in a new image from Webb’s Mid-Infrared Instrument (MIRI), is NGC 346 – the brightest and largest star-forming region in the Small Magellanic Cloud.

The Small Magellanic Cloud (SMC) is a satellite galaxy of the Milky Way, visible to the unaided eye in the southern constellation Tucana. This small companion galaxy is more primeval than the Milky Way in that it possesses fewer heavy elements, which are forged in stars through nuclear fusion and supernova explosions, compared to our own galaxy.

Since cosmic dust is formed from heavy elements like silicon and oxygen, scientists expected the SMC to lack significant amounts of dust. However the new MIRI image, as well as a previous image of NGC 346 from Webb’s Near-Infrared Camera released in January, show ample dust within this region.

In this representative-color image, blue tendrils trace emission from material that includes dusty silicates and sooty chemical molecules known as polycyclic aromatic hydrocarbons, or PAHs. More diffuse red emission shines from warm dust heated by the brightest and most massive stars in the heart of the region. An arc at the center left may be a reflection of light from the star near the arc’s center. (Similar, fainter arcs appear associated with stars at lower left and upper right.) Lastly, bright patches and filaments mark areas with abundant numbers of protostars. The research team looked for the reddest stars, and found 1,001 pinpoint sources of light, most of them young stars still embedded in their dusty cocoons.

By combining Webb data in both the near-infrared and mid-infrared, astronomers are able to take a fuller census of the stars and protostars within this dynamic region. The results have implications for our understanding of galaxies that existed billions of years ago, during an era in the universe known as “cosmic noon,” when star formation was at its peak and heavy element concentrations were lower, as seen in the SMC.

The James Webb Space Telescope is the world's premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

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About This Release

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Space Telescope Science Institute, Baltimore, Maryland

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Related Links and Documents

• Press Release: NASA’s Webb Uncovers Star Formation in Cluster’s Dusty Ribbons
• Press Release: Hubble Finds Infant Stars in Neighboring Galaxy

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NASA’s Webb Uncovers Star Formation in Cluster’s Dusty Ribbons

NGC 346 (NIRCam Image)
Credits: Science: NASA, ESA, CSA, Olivia C. Jones (UK ATC), Guido De Marchi (ESTEC), Margaret Meixner (USRA)
Image Processing: Alyssa Pagan (STScI), Nolan Habel (USRA), Laura Lenkić (USRA), Laurie E. U. Chu (NASA Ames)

Release Images | Release Videos

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NGC 346, one of the most dynamic star-forming regions in nearby galaxies, is full of mystery. Now, it is less mysterious with new findings from NASA’s James Webb Space Telescope. 

NCG 346 is located in the Small Magellanic Cloud (SMC), a dwarf galaxy close to our Milky Way. The SMC contains lower concentrations of elements heavier than hydrogen or helium, which astronomers call metals, compared to the Milky Way. Since dust grains in space are composed mostly of metals, scientists expected there would be low amounts of dust, and that it would be hard to detect. New data from Webb reveals the opposite.

Astronomers probed this region because the conditions and amount of metals within the SMC resemble those seen in galaxies billions of years ago, during an era in the universe known as “cosmic noon,” when star formation was at its peak. Some 2 to 3 billion years after the big bang, galaxies were forming stars at a furious rate. The fireworks of star formation happening then still shape the galaxies we see around us today.

“A galaxy during cosmic noon wouldn’t have one NGC 346 like the Small Magellanic Cloud does; it would have thousands” of star-forming regions like this one, said Margaret Meixner, an astronomer at the Universities Space Research Association and principal investigator of the research team. “But even if NGC 346 is now the one and only massive cluster furiously forming stars in its galaxy, it offers us a great opportunity to probe conditions that were in place at cosmic noon.” 

By observing protostars still in the process of forming, researchers can learn if the star formation process in the SMC is different from what we observe in our own Milky Way. Previous infrared studies of NGC 346 have focused on protostars heavier than about 5 to 8 times the mass of our Sun. “With Webb, we can probe down to lighter-weight protostars, as small as one tenth of our Sun, to see if their formation process is affected by the lower metal content,” said Olivia Jones of the United Kingdom Astronomy Technology Centre, Royal Observatory Edinburgh, a co-investigator on the program.

As stars form, they gather gas and dust, which can look like ribbons in Webb imagery, from the surrounding molecular cloud. The material collects into an accretion disk that feeds the central protostar. Astronomers have detected gas around protostars within NGC 346, but Webb’s near-infrared observations mark the first time they have also detected dust in these disks.

“We’re seeing the building blocks, not only of stars, but also potentially of planets,” said Guido De Marchi of the European Space Agency, a co-investigator on the research team. “And since the Small Magellanic Cloud has a similar environment to galaxies during cosmic noon, it’s possible that rocky planets could have formed earlier in the universe than we might have thought.”

The team also has spectroscopic observations from Webb’s NIRSpec instrument that they are continuing to analyze. These data are expected to provide new insights into the material accreting onto individual protostars, as well as the environment immediately surrounding the protostar.

These results are being presented Jan. 11 in a press conference at the 241st meeting of the American Astronomical Society. The observations were obtained as part of program 1227.

  The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

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Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
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Source: NASA's James Webb Space Telescope/News

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NASA's Hubble Finds Spiraling Stars, Providing Window into Early Universe

Spatial Distribution of NGC 346 Stars

The massive star cluster NGC 346, located in the Small Magellanic Cloud, has long intrigued astronomers with its unusual shape. Now researchers using two separate methods have determined that this shape is partly due to stars and gas spiraling into the center of this cluster in a river-like motion. The red spiral superimposed on NGC 346 traces the movement of stars and gas toward the center. Scientists say this spiraling motion is the most efficient way to feed star formation from the outside toward the center of the cluster. Credits: Illustration: NASA, ESA, Andi James (STScI). Release images

Nature likes spirals — from the whirlpool of a hurricane, to pinwheel-shaped protoplanetary disks around newborn stars, to the vast realms of spiral galaxies across our universe.

Now astronomers are bemused to find young stars that are spiraling into the center of a massive cluster of stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way.

The outer arm of the spiral in this huge, oddly shaped stellar nursery called NGC 346 may be feeding star formation in a river-like motion of gas and stars. This is an efficient way to fuel star birth, researchers say.

The Small Magellanic Cloud has a simpler chemical composition than the Milky Way, making it similar to the galaxies found in the younger universe, when heavier elements were more scarce. Because of this, the stars in the Small Magellanic Cloud burn hotter and so run out of their fuel faster than in our Milky Way.

Though a proxy for the early universe, at 200,000 light-years away the Small Magellanic Cloud is also one of our closest galactic neighbors.

Learning how stars form in the Small Magellanic Cloud offers a new twist on how a firestorm of star birth may have occurred early in the universe's history, when it was undergoing a "baby boom" about 2 to 3 billion years after the big bang (the universe is now 13.8 billion years old).

The new results find that the process of star formation there is similar to that in our own Milky Way.

Only 150 light-years in diameter, NGC 346 boasts the mass of 50,000 Suns. Its intriguing shape and rapid star-formation rate has puzzled astronomers. It took the combined power of NASA's Hubble Space Telescope and the European Southern Observatory's Very Large Telescope (VLT) to unravel the behavior of this mysterious-looking stellar nesting ground.

"Stars are the machines that sculpt the universe. We would not have life without stars, and yet we don't fully understand how they form," explained study leader Elena Sabbi of the Space Telescope Science Institute in Baltimore. "We have several models that make predictions, and some of these predictions are contradictory. We want to determine what is regulating the process of star formation, because these are the laws that we need to also understand what we see in the early universe."

Researchers determined the motion of the stars in NGC 346 in two different ways. Using Hubble, Sabbi and her team measured the changes of the stars' positions over 11 years. The stars in this region are moving at an average velocity of 2,000 miles per hour, which means that in 11 years they move 200 million miles. This is about 2 times the distance between the Sun and the Earth.

But this cluster is relatively far away, inside a neighboring galaxy. This means the amount of observed motion is very small and therefore difficult to measure. These extraordinarily precise observations were possible only because of Hubble's exquisite resolution and high sensitivity. Also, Hubble's three-decade-long history of observations provides a baseline for astronomers to follow minute celestial motions over time.

The second team, led by Peter Zeidler of AURA/STScI for the European Space Agency, used the ground-based VLT's Multi Unit Spectroscopic Explorer (MUSE) instrument to measure radial velocity, which determines whether an object is approaching or receding from an observer.

"What was really amazing is that we used two completely different methods with different facilities and basically came to the same conclusion, independent of each other," said Zeidler. "With Hubble, you can see the stars, but with MUSE we can also see the gas motion in the third dimension, and it confirms the theory that everything is spiraling inwards."

But why a spiral?

"A spiral is really the good, natural way to feed star formation from the outside toward the center of the cluster," explained Zeidler. "It's the most efficient way that stars and gas fueling more star formation can move towards the center."

Half of the Hubble data for this study of NGC 346 is archival. The first observations were taken 11 years ago. They were recently repeated to trace the motion of the stars over time. Given the telescope's longevity, the Hubble data archive now contains more than 32 years of astronomical data powering unprecedented, long-term studies.

"The Hubble archive is really a gold mine," said Sabbi. "There are so many interesting star-forming regions that Hubble has observed over the years. Given that Hubble is performing so well, we can actually repeat these observations. This can really advance our understanding of star formation."

The teams'findings appear Sept. 8 in The Astrophysical Journal.

Observations with NASA's James Webb Space Telescope should be able to resolve lower-mass stars in the cluster, giving a more holistic view of the region. Over Webb's lifespan, astronomers will be able to repeat this experiment and measure the motion of the low-mass stars. They could then compare the high-mass stars and the low-mass stars to finally learn the full extent of the dynamics of this nursery.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.

Source: HubbleSite/News

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Release: NASA, ESA, STScI

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Ann Jenkins
Space Telescope Science Institute, Baltimore, Maryland

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Elena Sabbi
Space Telescope Science Institute, Baltimore, Maryland

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AURA/STScI for the European Space Agency

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Related Links and Documents:

• Science Paper: The science paper by E. Sabbi et al., PDF (2.24 MB)
• Science Paper: The science paper by P. Zeidler et al., PDF (35.28 MB)
• NASA's Hubble Portal
• ESA/Hubble's Release

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The Epoch of Planet Formation, Times Twenty

NGC 346 (Multiwavelength)  
Credits: NASA, JPL-Caltech, and D. Gouliermis (Max-Planck Institute)

Webb’s infrared vision will help researchers tally the population of young stars

Billions of years ago, the young universe blazed with the brilliant light of myriad stars bursting to life. The young stars arising from this stellar "baby boom" are too far away and too faint for even the most powerful telescopes to study in detail. Astronomers will use the upcoming NASA James Webb Space Telescope to study star birth in the nearby Small Magellanic Cloud galaxy, which contains some of the same conditions that existed in galaxies during the universe’s peak star-formation epoch. Webb’s sharp infrared vision will help researchers take a census of medium-mass stars like our Sun still wrapped in their dense, dusty cocoons in the giant stellar nursery NGC 346, located about 200,000 light-years away. This census could help astronomers develop a clearer picture of how the galaxies of long ago churned out stars so rapidly.

The dazzling glow of young stars dominates images of the giant stellar nursery NGC 346, in the neighboring dwarf galaxy called the Small Magellanic Cloud. But this photogenic beauty is more than just a "pretty face."

NGC 346 is a nearby proxy for the myriad star-forming regions that existed when the universe was ablaze with star formation just a few billion years after the big bang. Astronomers do not have telescopes powerful enough to study the details of star formation in these faraway "baby-boom" galaxies. The Hubble Space Telescope imaged NGC 346 to identify the optically bright stars. However, to understand the star-formation process astronomers must peer through the dusty stellar nurseries. Observers will use the sharp infrared vision of NASA’s James Webb Space Telescope to study NGC 346, which could help them develop a clearer picture of how the galaxies of long ago churned out stars at such a tremendous rate.

Webb will allow astronomers to carry out an unprecedented, detailed analysis of a star-forming region that is deficient in elements heavier than hydrogen and helium. In the very early universe only hydrogen and helium (cooked up in the big bang) were available raw materials for star formation. Subsequent generations of stars created heavier elements in their cores through nuclear fusion and through supernova explosions. These elements, such as carbon, nitrogen, and oxygen, are recycled through subsequent generations of stars, planets, and in the case of Earth, all forms of life.

Another link between NGC 346 and the star-forming heyday is the large amount of young, massive stars residing in these fertile areas. These stellar giants wreak havoc on their environment by unleashing searing ultraviolet radiation and powerful stellar winds (streams of charged particles). Energy from these "bullying" monster stars can destroy star-forming clouds of gas and dust and disrupt the disks encircling stars where planets can form.

"The Small Magellanic Cloud could be a local astrophysical laboratory to study processes that happened at the peak star-formation epoch, because those early galaxies contained lots of massive stars and were deficient in heavier elements," said lead researcher Margaret Meixner, of the Space Telescope Science Institute and the Johns Hopkins University, both in Baltimore, Maryland. "The questions are what is the process of star formation in galaxies lacking heavier elements and how is star formation there different than star formation in the Milky Way, which contains heavier elements? You need to get a census of all the forming stars to answer these questions."

A Census of Smaller-mass Stars

The Milky Way contains about 25 percent more heavier elements than the Small Magellanic Cloud. Numerous studies have been conducted on how stars form in the heavier-element-rich Milky Way. But Milky Way stars are nearby, while the stars in the Small Magellanic Cloud are too far away to study all of them in detail. "We’re really hoping to study the NGC 346 region on the scales that we’ve been able to study star formation in our Milky Way galaxy," added team member Isha Nayak of the Johns Hopkins University in Baltimore, Maryland. "It’s hard to resolve things even in nearby galaxies like the Small Magellanic Cloud in the same manner as we can do in our own neighborhood. One question we want answered is, do all of these stars develop in the same way?"

The Webb observations will continue the work started by astronomers using telescopes such as the Herschel Space Observatory and NASA’s Spitzer Space Telescope. Spitzer and Herschel observations provided a census of the massive stars forming in NGC 346, which are eight times our Sun’s mass or larger. But Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Imager (MIRI) instruments have the sharpness to catch the smaller stars, from eight solar masses to less than a solar mass.

Astronomers will then have the complete mass distribution of stars in NGC 346. The Webb census may uncover as many as 10,000 young, dust-enshrouded fledgling stars, many of them less than a million years old.v Probing Dusty, Planet-forming Disksv Some of the fledgling stars in NGC 346 have protoplanetary disks encircling them, where planets may form. Researchers will use NIRCam and the MIRI imager to detect the near-infrared dust emission in these disks. "We will be able to determine if these disks are similar to the types of disks we see in our local solar neighborhood that are forming planetary systems," Meixner said. "And, we hope to answer whether planetary systems can form in areas deficient in heavier elements or in very extreme star-forming conditions."

It may be harder to make planets in environments largely lacking heavier elements. "When you have an environment deficient in heavier elements, the ultraviolet radiation from high-mass stars can penetrate much deeper into a molecular gas cloud where stars are forming, so it’s hard for low-mass stars, let alone planets, to form in such an environment," Nayak said.

Dust may be a nuisance for many people, but it is important for star formation. It helps to shield the dense, cold, gaseous cloud in which stars form from scorching radiation and harsh stellar winds that could tear the cloud apart. "Dust plays an important role with providing a safe haven for a stellar nursery," Meixner explained.

Webb’s spectrographs will pinpoint the densest, dustiest regions where star formation is happening and will probe the evolution of the protoplanetary disks. "The question is what do you need to form stars?" Meixner said. "Maybe we will find a relationship between star formation and its environment."

The observations described here will be taken as part of Webb’s Guaranteed Time Observation (GTO) program. The GTO program provides dedicated time to the scientists who have worked with NASA to craft the science and instrument capabilities of Webb throughout its development.

The James Webb Space Telescope will be the world's premier space science observatory when it launches in 2021. Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, the European Space Agency (ESA) and the Canadian Space Agency.

Source: NASA's James Webb Space Telescope

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Light, Wind and Fire

PR Image eso1008a

Star-forming region NGC 346

PR Image eso1008b

Around NGC 346

PR Video eso1008a

Zoom in on the star-forming region NGC 346

PR Video eso1008b

Close-up zoom on the star-forming region NGC 346

Beautiful Image of a Cosmic Sculpture

Today ESO has released a dramatic new image of NGC 346, the brightest star-forming region in our neighbouring galaxy, the Small Magellanic Cloud, 210 000 light-years away towards the constellation of Tucana (the Toucan). The light, wind and heat given off by massive stars have dispersed the glowing gas within and around this star cluster, forming a surrounding wispy nebular structure that looks like a cobweb. NGC 346, like other beautiful astronomical scenes, is a work in progress, and changes as the aeons pass. As yet more stars form from loose matter in the area, they will ignite, scattering leftover dust and gas, carving out great ripples and altering the face of this lustrous object.

NGC 346 spans approximately 200 light-years, a region of space about fifty times the distance between the Sun and its nearest stellar neighbours. Astronomers classify NGC 346 as an open cluster of stars, indicating that this stellar brood all originated from the same collapsed cloud of matter. The associated nebula containing this clutch of bright stars is known as an emission nebula, meaning that gas within it has been heated up by stars until the gas emits its own light, just like the neon gas used in electric store signs.

Many stars in NGC 346 are relatively young in cosmic terms with their births dating back only a few million years or so (eso0834). Powerful winds thrown off by a massive star set off this recent round of star birth by compressing large amounts of matter, the first critical step towards igniting new stars. This cloud of material then collapses under its own gravity, until some regions become dense and hot enough to roar forth as a brilliantly shining, nuclear fusion-powered furnace — a star, illuminating the residual debris of gas and dust. In sufficiently congested regions like NGC 346, with high levels of recent star birth, the result is a glorious, glowing vista for our telescopes to capture.

NGC 346 is in the Small Magellanic Cloud, a dwarf galaxy some 210 000 light-years away from Earth and in close proximity to our home, the much larger Milky Way Galaxy. Like its sister the Large Magellanic Cloud, the Small Magellanic Cloud is visible with the unaided eye from the southern hemisphere and has served as an extragalactic laboratory for astronomers studying the dynamics of star formation.

This particular image was obtained using the Wide Field Imager (WFI) instrument at the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. Images like this help astronomers chronicle star birth and evolution, while offering glimpses of how stellar development influences the appearance of the cosmic environment over time.

More information

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory, and VISTA the largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Contacts

Henri Boffin

ESO ePOD

Garching, Germany

Tel: +49 89 3200 6222

Email: hboffin@eso.org