NASA’s James Webb Space Telescope has revealed the once-hidden features of the protostar within the dark cloud L1527, providing insight into the beginnings of a new star. These blazing clouds within the Taurus star-forming region are only visible in infrared light, making it an ideal target for Webb’s Near-Infrared Camera (NIRCam).

The protostar itself is hidden from view within the “neck” of this hourglass shape. An edge-on protoplanetary disk is seen as a dark line across the middle of the neck. Light from the protostar leaks above and below this disk, illuminating cavities within the surrounding gas and dust.

The protostar within the dark cloud L1527, shown in this image from NASA’s James Webb Space Telescope Near-Infrared Camera (NIRCam), is embedded within a cloud of material feeding its growth. Ejections from the star have cleared out cavities above and below it, whose boundaries glow orange and blue in this infrared view. The upper central region displays bubble-like shapes due to stellar “burps,” or sporadic ejections.

Credits: NASA, ESA, CSA, and STScI. Image processing: J. DePasquale, A. Pagan, and A. Koekemoer (STScI)

Download the full-resolution image from the Space Telescope Science Institute.

The region’s most prevalent features, the clouds colored blue and orange in this representative-color infrared image, outline cavities created as material shoots away from the protostar and collides with surrounding matter. The colors themselves are due to layers of dust between Webb and the clouds. The blue areas are where the dust is thinnest. The thicker the layer of dust, the less blue light is able to escape, creating pockets of orange.

Webb also reveals filaments of molecular hydrogen that have been shocked as the protostar ejects material away from it. Shocks and turbulence inhibit the formation of new stars, which would otherwise form all throughout the cloud. As a result, the protostar dominates the space, taking much of the material for itself.

Despite the chaos that L1527 causes, it’s only about 100,000 years old - a relatively young body. Given its age and its brightness in far-infrared light as observed by missions like the Infrared Astronomical Satellite, L1527 is considered a class 0 protostar, the earliest stage of star formation. Protostars like these, which are still cocooned in a dark cloud of dust and gas, have a long way to go before they become full-fledged stars. L1527 doesn’t generate its own energy through nuclear fusion of hydrogen yet, an essential characteristic of stars. Its shape, while mostly spherical, is also unstable, taking the form of a small, hot, and puffy clump of gas somewhere between 20 and 40% the mass of our Sun.

As the protostar continues to gather mass, its core gradually compresses and gets closer to stable nuclear fusion. The scene shown in this image reveals L1527 doing just that. The surrounding molecular cloud is made up of dense dust and gas being drawn to the center, where the protostar resides. As the material falls in, it spirals around the center. This creates a dense disk of material, known as an accretion disk, which feeds material to the protostar. As it gains more mass and compresses further, the temperature of its core will rise, eventually reaching the threshold for nuclear fusion to begin.

The disk, seen in the image as a dark band in front of the bright center, is about the size of our solar system. Given the density, it’s not unusual for much of this material to clump together - the beginnings of planets. Ultimately, this view of L1527 provides a window into what our Sun and solar system looked like in their infancy.

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.

Quelle: NASA

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Update: 19.11.2022

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Webb Space Telescope spots early galaxies hidden from Hubble

NASA's new Webb Space Telescope is finding bright, early galaxies that until now have been hidden from view

CAPE CANAVERAL, Fla. -- NASA’s Webb Space Telescope is finding bright, early galaxies that until now were hidden from view, including one that may have formed a mere 350 million years after the cosmic-creating Big Bang.

Astronomers said Thursday that if the results are verified, this newly discovered throng of stars would beat the most distant galaxy identified by the Hubble Space Telescope, a record-holder that formed 400 million years after the universe began.

Launched last December as a successor to Hubble, the Webb telescope is indicating stars may have formed sooner than previously thought — perhaps within a couple million years of creation.

Webb's latest discoveries were detailed in the Astrophysical Journal Lettersby an international team led by Rohan Naidu of the Harvard-Smithsonian Center for Astrophysics. The article elaborates on two exceptionally bright galaxies, the first thought to have formed 350 million years after the Big Bang and the other 450 million years after.

Naidu said more observations are needed in the infrared by Webb before claiming a new distance record-holder.

Although some researchers report having uncovered galaxies even closer to the creation of the universe 13.8 billion years ago, those candidates have yet to be verified, scientists stressed at a NASA news conference. Some of those could be later galaxies mimicking earlier ones, they noted.

“This is a very dynamic time," said Garth Illingworth of the University of California, Santa Cruz, a co-author of the article published Thursday. “There have been lots of preliminary announcements of even earlier galaxies, and we’re still trying to sort out as a community which ones of those are likely to be real.”

Tommaso Treu of the University of California, Los Angeles, a chief scientist for Webb's early release science program, said the evidence presented so far “is as solid as it gets” for the galaxy believed to have formed 350 million after the Big Bang.

If the findings are verified and more early galaxies are out there, Naidu and his team wrote that Webb “will prove highly successful in pushing the cosmic frontier all the way to the brink of the Big Bang.”

"When and how the first galaxies formed remains one of the most intriguing questions," they said in their paper.

NASA's Jane Rigby, a project scientist with Webb, noted that these galaxies “were hiding just under the limits of what Hubble could do.”

“They were right there waiting for us,” she told reporters. “So that's a happy surprise that there are lots of these galaxies to study.”

The $10 billion observatory — the world's largest and most powerful telescope ever sent into space — is in a solar orbit that's 1 million miles (1.6 million kilometers) from Earth. Full science operations began over the summer, and NASA has since released a series of dazzling snapshots of the universe.

Quelle: abcNews

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Update: 24.11.2022

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NASA’s Webb Reveals an Exoplanet Atmosphere as Never Seen Before

NASA’s James Webb Space Telescope just scored another first: a molecular and chemical profile of a distant world’s skies.

While Webb and other space telescopes, including NASA’s Hubble and Spitzer, previously have revealed isolated ingredients of this broiling planet’s atmosphere, the new readings from Webb provide a full menu of atoms, molecules, and even signs of active chemistry and clouds.

The latest data also gives a hint of how these clouds might look up close: broken up rather than a single, uniform blanket over the planet.

The telescope’s array of highly sensitive instruments was trained on the atmosphere of WASP-39 b, a “hot Saturn” (a planet about as massive as Saturn but in an orbit tighter than Mercury) orbiting a star some 700 light-years away.

The findings bode well for the capability of Webb’s instruments to conduct the broad range of investigations of all types of exoplanets – planets around other stars – hoped for by the science community. That includes probing the atmospheres of smaller, rocky planets like those in the TRAPPIST-1 system.

“We observed the exoplanet with multiple instruments that, together, provide a broad swath of the infrared spectrum and a panoply of chemical fingerprints inaccessible until [this mission],” said Natalie Batalha, an astronomer at the University of California, Santa Cruz, who contributed to and helped coordinate the new research. “Data like these are a game changer.”

The suite of discoveries is detailed in a set of five new scientific papers, three of which are in press and two of which are under review. Among the unprecedented revelations is the first detection in an exoplanet atmosphere of sulfur dioxide (SO₂), a molecule produced from chemical reactions triggered by high-energy light from the planet’s parent star. On Earth, the protective ozone layer in the upper atmosphere is created in a similar way.

“This is the first time we see concrete evidence of photochemistry – chemical reactions initiated by energetic stellar light – on exoplanets,” said Shang-Min Tsai, a researcher at the University of Oxford in the United Kingdom and lead author of the paper explaining the origin of sulfur dioxide in WASP-39 b’s atmosphere. “I see this as a really promising outlook for advancing our understanding of exoplanet atmospheres with [this mission].”

This led to another first: scientists applying computer models of photochemistry to data that requires such physics to be fully explained. The resulting improvements in modeling will help build the technological know-how to interpret potential signs of habitability in the future.

“Planets are sculpted and transformed by orbiting within the radiation bath of the host star,” Batalha said. “On Earth, those transformations allow life to thrive.”

The planet’s proximity to its host star – eight times closer than Mercury is to our Sun – also makes it a laboratory for studying the effects of radiation from host stars on exoplanets. Better knowledge of the star-planet connection should bring a deeper understanding of how these processes affect the diversity of planets observed in the galaxy.

To see light from WASP-39 b, Webb tracked the planet as it passed in front of its star, allowing some of the star’s light to filter through the planet’s atmosphere. Different types of chemicals in the atmosphere absorb different colors of the starlight spectrum, so the colors that are missing tell astronomers which molecules are present. By viewing the universe in infrared light, Webb can pick up chemical fingerprints that can’t be detected in visible light.

Other atmospheric constituents detected by the Webb telescope include sodium (Na), potassium (K), and water vapor (H₂O), confirming previous space and ground-based telescope observations as well as finding additional fingerprints of water, at these longer wavelengths, that haven’t been seen before.

Webb also saw carbon dioxide (CO₂) at higher resolution, providing twice as much data as reported from its previous observations. Meanwhile, carbon monoxide (CO) was detected, but obvious signatures of both methane (CH₄) and hydrogen sulfide (H₂S) were absent from the Webb data. If present, these molecules occur at very low levels.

To capture this broad spectrum of WASP-39 b’s atmosphere, an international team numbering in the hundreds independently analyzed data from four of the Webb telescope’s finely calibrated instrument modes.

The atmospheric composition of the hot gas giant exoplanet WASP-39 b has been revealed by NASA’s James Webb Space Telescope. This graphic shows four transmission spectra from three of Webb’s instruments operated in four instrument modes. At upper left, data from NIRISS shows fingerprints of potassium (K), water (H2O), and carbon monoxide (CO). At upper right, data from NIRCam shows a prominent water signature. At lower left, data from NIRSpec indicates water, sulfur dioxide (SO2), carbon dioxide (CO2), and carbon monoxide (CO). At lower right, additional NIRSpec data reveals all of these molecules as well as sodium (Na).

Credits: NASA, ESA, CSA, J. Olmsted (STScI)

Download the full-resolution image from the Space Telescope Science Institute.

“We had predicted what [the telescope] would show us, but it was more precise, more diverse, and more beautiful than I actually believed it would be,” said Hannah Wakeford, an astrophysicist at the University of Bristol in the United Kingdom who investigates exoplanet atmospheres.

Having such a complete roster of chemical ingredients in an exoplanet atmosphere also gives scientists a glimpse of the abundance of different elements in relation to each other, such as carbon-to-oxygen or potassium-to-oxygen ratios. That, in turn, provides insight into how this planet – and perhaps others – formed out of the disk of gas and dust surrounding the parent star in its younger years.

WASP-39 b’s chemical inventory suggests a history of smashups and mergers of smaller bodies called planetesimals to create an eventual goliath of a planet.

“The abundance of sulfur [relative to] hydrogen indicated that the planet presumably experienced significant accretion of planetesimals that can deliver [these ingredients] to the atmosphere,” said Kazumasa Ohno, a UC Santa Cruz exoplanet researcher who worked on Webb data. “The data also indicates that the oxygen is a lot more abundant than the carbon in the atmosphere. This potentially indicates that WASP-39 b originally formed far away from the central star.”

In so precisely parsing an exoplanet atmosphere, the Webb telescope’s instruments performed well beyond scientists’ expectations – and promise a new phase of exploration among the broad variety of exoplanets in the galaxy.

“We are going to be able to see the big picture of exoplanet atmospheres,” said Laura Flagg, a researcher at Cornell University and a member of the international team. “It is incredibly exciting to know that everything is going to be rewritten. That is one of the best parts of being a scientist.”

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 CSA (Canadian Space Agency).

Quelle: NASA

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Update: 3.12.2022

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James Webb Space Telescope view of Saturn's weirdest moon Titan thrills scientists

It's been a cloudy season for Saturn's largest moon, Titan.

Titan is a strange world — a little bit Earthlike, if land were made of water ice, rivers and seas were filled with liquid methane and other hydrocarbons, and the atmosphere were thick and hazy, dotted with methane clouds. And now, the James Webb Space Telescope (Webb or JWST) has observed two of those clouds during observations on Nov. 4 that have thrilled scientists, according to a NASA statement.

"Fantastic! Love seeing the cloud and the obvious albedo markings," Heidi Hammel, a planetary scientist at the Association of Universities for Research in Astronomy and a project lead for JWST's solar system work, wrote in an email shared in the statement, referring to glimpses of bright and dark regions of Titan's surface.

Two views of Saturn's moon Titan captured by the James Webb Space Telescope's NIRCam instrument.  (Image credit: NASA, ESA, CSA, Webb Titan GTO Team/Alyssa Pagan (STScI))

Conor Nixon, an astronomer at NASA's Goddard Space Flight Center in Maryland, arranged for JWST to spend a total of 15 hours of its first year studying Titan. In particular, Nixon's team wanted to study Titan's atmosphere, aiming to map the distribution of the haze and identify new gases, among other goals.

And the scientists were thrilled at the data JWST sent them. "At first glance, it is simply extraordinary," Sebastien Rodriguez, an astronomer at the Université Paris Cité and colleague on the research, wrote in an email shared in the statement. "I think we're seeing a cloud!"

As they pored over the data, the researchers identified not one but two clouds, including, intriguingly, one located over Kraken Mare, the largest of Titan's seas. The scientists were soon inspired to find a way to check back in on those clouds to understand how they changed over time. The team reached out to the Keck Observatory in Hawai'i, which was able to snag observations of Titan just two days after JWST.

On the left, the James Webb Space Telescope Nov. 4, 2022, observations of Titan; on the right, Keck Observatory's view two days later.  (Image credit: NASA, ESA, CSA, Webb Titan GTO Team/Alyssa Pagan (STScI)

"We were concerned that the clouds would be gone when we looked at Titan two days later with Keck," Imke de Pater, an astronomer at the University of California, Berkeley, who leads Keck's observations of Titan, said in the statement. "But to our delight there were clouds at the same positions, looking like they had changed in shape."

However, that alignment doesn't necessarily mean Keck saw the same clouds as JWST. Scientists expected high cloud activity because Titan's northern hemisphere is experiencing late summer and catching more solar radiation, so Keck's clouds may have been freshly formed.

And the scientists aren't done mining the observations. They identified the clouds in images taken by JWST's Near-Infrared Camera (NIRCam), a powerful camera that can image a target in several different wavelengths of light, which in the case of Titan allows scientists to separate out the lower atmosphere.

On the left, the James Webb Space Telescope Nov. 4, 2022, observations of Titan; in the middle, Keck Observatory's view two days later; on the right Keck's view Nov. 7, 2022.  (Image credit: NASA/STScI/W. M. Keck Observatory/Judy Schmidt)

But the researchers haven't even finished evaluating all of NIRCam's data, and a second instrument was also at work. The observatory's Near-Infrared Spectrograph (NIRSpec) gathered spectra. This technique splits light reflected off, for example, Titan's atmosphere and measures how much of each wavelength of light is present. The spectra should help scientists map what compounds are present in the lower atmosphere — including a strange bright spot over the moon's south pole.

JWST is also scheduled to return its sharp gaze to Titan in May or June 2023, according to the statement, this time using its Mid-Infrared Instrument (MIRI), which will refine scientists' understanding of the chemicals in the moon's strange, hazy atmosphere.

Observations of Titan are particularly important now, in a lull between spacecraft visitors to the icy moon. NASA's Cassini mission arrived at Saturn in 2004 and flew past the moon more than a hundred times before the spacecraft's demise in 2017. And NASA is working on a new mission, called Dragonfly, which is dedicated to Titan and will see a drone flying through the hazy skies, allowing scientists to study the moon from some two dozen vantage points.

Quelle: SC

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Update: 10.12.2022

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NASA’s Webb Indicates Several Stars ‘Stirred Up’ Southern Ring Nebula

Some of the first data from NASA’s James Webb Space Telescope has shown there were at least two, and possibly three, more unseen stars that crafted the oblong, curvy shapes of the Southern Ring Nebula. Plus, for the first time, by pairing Webb’s infrared images with existing data from ESA’s (European Space Agency’s) Gaia observatory, researchers were able to precisely pinpoint the mass of the central star before it created the nebula. A team of almost 70 researchers led by Orsola De Marco of Macquarie University in Sydney, Australia, analyzed Webb’s 10 highly detailed exposures of this dying star to produce these results.

Their calculations show the central star was nearly three times the mass of the Sun before it ejected its layers of gas and dust. After those ejections, it now measures about 60 percent of the mass of the Sun. Knowing the initial mass is a critical piece of evidence that helped the team reconstruct the scene and project how the shapes in this nebula may have been created.