21.09.2022
Mars is mighty in first Webb observations of Red Planet
The James Webb Space Telescope captured its first images and spectra of Mars on 5 September 2022. The telescope, an international collaboration between NASA, ESA and the Canadian Space Agency, provides a unique perspective with its infrared sensitivity on our neighbouring planet, complementing data being collected by orbiters, rovers, and other telescopes.
Webb’s unique observation post nearly 1.5 million kilometres away at the Sun-Earth Lagrange point 2 (L2) provides a view of Mars’ observable disk (the portion of the sunlit side that is facing the telescope). As a result, Webb can capture images and spectra with the spectral resolution needed to study short-term phenomena like dust storms, weather patterns, seasonal changes, and, in a single observation, processes that occur at different times (daytime, sunset, and nighttime) of a Martian day.
Because it is so close, the Red Planet is one of the brightest objects in the night sky in terms of both visible light (which human eyes can see) and the infrared light that Webb is designed to detect. This poses special challenges to the observatory, which was built to detect the extremely faint light of the most distant galaxies in the universe. Webb’s instruments are so sensitive that without special observing techniques, the bright infrared light from Mars is blinding, causing a phenomenon known as “detector saturation.” Astronomers adjusted for Mars’ extreme brightness by using very short exposures, measuring only some of the light that hit the detectors, and applying special data analysis techniques.
Webb’s first images of Mars, captured by the Near-Infrared Camera (NIRCam), show a region of the planet’s eastern hemisphere at two different wavelengths, or colours of infrared light. This image shows a surface reference map from NASA and the Mars Orbiter Laser Altimeter (MOLA) on the left, with the two Webb NIRCam instrument field of views overlaid. The near-infrared images from Webb are shown on the right.
First Webb infrared spectrum of Mars
Webb’s first near-infrared spectrum of Mars, captured by the Near-Infrared Spectrograph (NIRSpec), demonstrates Webb’s power to study the Red Planet with spectroscopy.
Whereas the Mars images show differences in brightness integrated over a large number of wavelengths from place to place across the planet at a particular day and time, the spectrum shows the subtle variations in brightness between hundreds of different wavelengths representative of the planet as a whole. Astronomers will analyse the features of the spectrum to gather additional information about the surface and atmosphere of the planet.
In the future, Webb will be using this imaging and spectroscopic data to explore regional differences across the planet, and to search for trace species in the atmosphere, including methane and hydrogen chloride.
These observations of Mars were conducted as part of Webb’s Cycle 1 Guaranteed Time Observation (GTO) Solar System program led by Heidi Hammel of the Association of Universities for Research in Astronomy (AURA).
ESA operates two Mars orbiters, Mars Express and the ExoMars Trace Gas Orbiter, that have brought a treasury of insight into the Red Planet’s atmosphere and surface. Furthermore, ESA collaborates with the Japanese Aerospace Exploration Agency (JAXA) on the Martian Moons eXploration (MMX) mission, soon to launch for Mars’ moon Phobos.
NIRSpec was built for the European Space Agency (ESA) by a consortium of European companies led by Airbus Defence and Space (ADS) with NASA’s Goddard Space Flight Centre providing its detector and micro-shutter subsystems.
Quelle: ESA
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Update: 22.09.2022
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New Webb Image Captures Clearest View of Neptune’s Rings in Decades
NASA’s James Webb Space Telescope shows off its capabilities closer to home with its first image of Neptune. Not only has Webb captured the clearest view of this distant planet’s rings in more than 30 years, but its cameras reveal the ice giant in a whole new light.
Most striking in Webb’s new image is the crisp view of the planet’s rings – some of which have not been detected since NASA’s Voyager 2 became the first spacecraft to observe Neptune during its flyby in 1989. In addition to several bright, narrow rings, the Webb image clearly shows Neptune’s fainter dust bands.
“It has been three decades since we last saw these faint, dusty rings, and this is the first time we’ve seen them in the infrared,” notes Heidi Hammel, a Neptune system expert and interdisciplinary scientist for Webb. Webb’s extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune.
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Neptune has fascinated researchers since its discovery in 1846. Located 30 times farther from the Sun than Earth, Neptune orbits in the remote, dark region of the outer solar system. At that extreme distance, the Sun is so small and faint that high noon on Neptune is similar to a dim twilight on Earth.
This planet is characterized as an ice giant due to the chemical make-up of its interior. Compared to the gas giants, Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium. This is readily apparent in Neptune’s signature blue appearance in Hubble Space Telescope images at visible wavelengths, caused by small amounts of gaseous methane.
Webb’s Near-Infrared Camera (NIRCam) images objects in the near-infrared range from 0.6 to 5 microns, so Neptune does not appear blue to Webb. In fact, the methane gas so strongly absorbs red and infrared light that the planet is quite dark at these near-infrared wavelengths, except where high-altitude clouds are present. Such methane-ice clouds are prominent as bright streaks and spots, which reflect sunlight before it is absorbed by methane gas. Images from other observatories, including the Hubble Space Telescope and the W.M. Keck Observatory, have recorded these rapidly evolving cloud features over the years.
More subtly, a thin line of brightness circling the planet’s equator could be a visual signature of global atmospheric circulation that powers Neptune’s winds and storms. The atmosphere descends and warms at the equator, and thus glows at infrared wavelengths more than the surrounding, cooler gases.
Neptune’s 164-year orbit means its northern pole, at the top of this image, is just out of view for astronomers, but the Webb images hint at an intriguing brightness in that area. A previously-known vortex at the southern pole is evident in Webb’s view, but for the first time Webb has revealed a continuous band of high-latitude clouds surrounding it.
Webb also captured seven of Neptune’s 14 known moons. Dominating this Webb portrait of Neptune is a very bright point of light sporting the signature diffraction spikes seen in many of Webb’s images, but this is not a star. Rather, this is Neptune’s large and unusual moon, Triton.
Covered in a frozen sheen of condensed nitrogen, Triton reflects an average of 70 percent of the sunlight that hits it. It far outshines Neptune in this image because the planet’s atmosphere is darkened by methane absorption at these near-infrared wavelengths. Triton orbits Neptune in an unusual backward (retrograde) orbit, leading astronomers to speculate that this moon was originally a Kuiper belt object that was gravitationally captured by Neptune. Additional Webb studies of both Triton and Neptune are planned in the coming year.
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: 25.09.2022
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Can the James Webb Space Telescope really see the past?
Scientists want to use Webb to see the beginning of the universe. How is that possible?
A combined optical/mid-infrared image featuring data from both the Hubble Space Telescope and the James Webb Space Telescope. It is in a spiral pattern. (Image credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST Team; ESA/Hubble & NASA, R. Chandar. Acknowledgement: J. Schmidt)
On July 11, the James Webb Space Telescope (JWST) made history by releasing its debut image: a jewel-filled photo that's been touted as the deepest photo of the universe ever taken.
Besides looking farther across space than any observatory before it, the James Webb Space Telescope has another trick up its mirrors: It can look further back in time than any other telescope, observing distant stars and galaxies as they appeared 13.5 billion years ago, not long after the beginning of the universe as we know it.
How is this possible? How can a machine look "back in time"? It's not magic; it's just the nature of light.
"Telescopes can be time machines. Looking out in space is like looking back in time," NASA scientists explained on WebbTelescope.org(opens in new tab). "It sounds magical, but it's actually very simple: Light needs time to travel across the vast distances of space to reach us."
NASA's James Webb Space Telescope has produced the deepest and sharpest infrared image of the distant universe to date. Known as Webb's First Deep Field, this image of galaxy cluster SMACS 0723 is overflowing with detail. (Image credit: NASA, ESA, CSA, and STScI)
All of the light you see — from the twinkling of distant stars to the glow from your desk lamp a few feet away — takes time to reach your eyes. Luckily, light moves staggeringly fast — roughly 670 million mph (1 billion kph) — so you'll never notice it traveling from, say, the desk lamp to your eyes.
However, when you're looking at objects that are millions or billions of miles away — as most objects in the night sky are — you're seeing light that has traveled a long, long way to reach you.
Take the sun, for example. Earth's home star sits an average of 93 million miles (150 million kilometers) away. That means it takes light about 8 minutes, 20 seconds to travel from the sun to Earth. So, when you look at the sun (although you should never look directly at the sun(opens in new tab)), you're seeing it as it appeared more than 8 minutes ago, not as it appears right now — in other words, you're looking 8 minutes into the past.
The speed of light is so important to astronomy that scientists prefer to use light-years, rather than miles or kilometers, to measure great distances in space. One light-year is the distance that light can travel in one year: roughly 5.88 trillion miles, or 9.46 trillion km. For example, the North Star, Polaris, sits about 323 light-years from Earth. Whenever you see this star, you're seeing light that's more than 300 years old.
So, you don't even need a fancy telescope to see back in time; you can do it with your own naked eyes. But to look truly far into the past (say, back to the beginning of the universe), astronomers need telescopes like JWST. Not only can JWST zoom in on distant galaxies to observe visible light coming from many millions of light-years away, but it can also pick up wavelengths of light that are invisible to human eyes, such as infrared waves.
Many things, including humans, emit heat as infrared energy. This energy can't be seen with the naked eye. But when infrared waves are viewed with the right equipment, they can reveal some of the hardest-to-find objects in the universe. Because infrared radiation has a much longer wavelength than visible light does, it can pass through dense, dusty regions of space without being scattered or absorbed, according to NASA(opens in new tab). Many stars and galaxies that are too far, faint or obscured to see as visible light emit heat energy that can be detected as infrared radiation.
This is one of JWST's handiest tricks. Using its infrared-sensing instruments, the telescope can peer past dusty regions of space to study light that was emitted more than 13 billion years ago by the most ancient stars and galaxies in the universe.
That's how JWST took its famous deep field image, and that's how it will attempt to look even further back in time, to the first few hundred million years(opens in new tab) after the Big Bang. The stars that the telescope will reveal may actually be long-dead today, but as their ancient light makes the lengthy journey across the universe, JWST treats our mortal eyes to a one-of-a-kind time travel display.
Quelle: SC
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Update: 1.10.2022
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Two of NASA’s Great Observatories, the James Webb Space Telescope and the Hubble Space Telescope, have captured views of a unique NASA experiment designed to intentionally smash a spacecraft into a small asteroid in the world’s first-ever in-space test for planetary defense. These observations of NASA’s Double Asteroid Redirection Test (DART) impact mark the first time that Webb and Hubble simultaneously observed the same celestial target.
On Sept. 26, 2022, at 7:14 pm EDT, DART intentionally crashed into Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos. It was the world’s first test of the kinetic impact mitigation technique, using a spacecraft to deflect an asteroid that poses no threat to Earth, and modifying the object’s orbit. DART is a test for defending Earth against potential asteroid or comet hazards.
The coordinated Hubble and Webb observations are more than just an operational milestone for each telescope – there are also key science questions relating to the makeup and history of our solar system that researchers can explore when combining the capabilities of these observatories.
“Webb and Hubble show what we’ve always known to be true at NASA: We learn more when we work together,” said NASA Administrator Bill Nelson. “For the first time, Webb and Hubble have simultaneously captured imagery from the same target in the cosmos: an asteroid that was impacted by a spacecraft after a seven-million-mile journey. All of humanity eagerly awaits the discoveries to come from Webb, Hubble, and our ground-based telescopes – about the DART mission and beyond.”
Observations from Webb and Hubble together will allow scientists to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, and how fast it was ejected. Additionally, Webb and Hubble captured the impact in different wavelengths of light – Webb in infrared and Hubble in visible. Observing the impact across a wide array of wavelengths will reveal the distribution of particle sizes in the expanding dust cloud, helping to determine whether it threw off lots of big chunks or mostly fine dust. Combining this information, along with ground-based telescope observations, will help scientists to understand how effectively a kinetic impact can modify an asteroid’s orbit.
Webb Captures Impact Site Before and After Collision
Webb took one observation of the impact location before the collision took place, then several observations over the next few hours. Images from Webb’s Near-Infrared Camera (NIRCam) show a tight, compact core, with plumes of material appearing as wisps streaming away from the center of where the impact took place.
Observing the impact with Webb presented the flight operations, planning, and science teams with unique challenges, because of the asteroid’s speed of travel across the sky. As DART approached its target, the teams performed additional work in the weeks leading up to the impact to enable and test a method of tracking asteroids moving over three times faster than the original speed limit set for Webb.
“I have nothing but tremendous admiration for the Webb Mission Operations folks that made this a reality,” said principal investigator Cristina Thomas of Northern Arizona University in Flagstaff, Arizona. “We have been planning these observations for years, then in detail for weeks, and I’m tremendously happy this has come to fruition.”
Scientists also plan to observe the asteroid system in the coming months using Webb’s Mid-Infrared Instrument (MIRI) and Webb’s Near-Infrared Spectrograph (NIRSpec). Spectroscopic data will provide researchers with insight into the asteroid’s chemical composition.
Webb observed the impact over five hours total and captured 10 images. The data was collected as part of Webb’s Cycle 1 Guaranteed Time Observation Program 1245 led by Heidi Hammel of the Association of Universities for Research in Astronomy (AURA).
Hubble Images Show Movement of Ejecta After Impact
Hubble also captured observations of the binary system ahead of the impact, then again 15 minutes after DART hit the surface of Dimorphos. Images from Hubble’s Wide Field Camera 3 show the impact in visible light. Ejecta from the impact appear as rays stretching out from the body of the asteroid. The bolder, fanned-out spike of ejecta to the left of the asteroid is in the general direction from which DART approached.
Some of the rays appear to be curved slightly, but astronomers need to take a closer look to determine what this could mean. In the Hubble images, astronomers estimate that the brightness of the system increased by three times after impact, and saw that brightness hold steady, even eight hours after impact.
Hubble plans to monitor the Didymos-Dimorphos system 10 more times over the next three weeks. These regular, relatively long-term observations as the ejecta cloud expands and fades over time will paint a more complete picture of the cloud’s expansion from the ejection to its disappearance.
“When I saw the data, I was literally speechless, stunned by the amazing detail of the ejecta that Hubble captured,” said Jian-Yang Li of the Planetary Science Institute in Tucson, Arizona, who led the Hubble observations. “I feel lucky to witness this moment and be part of the team that made this happen.”
Hubble captured 45 images in the time immediately before and following DART’s impact with Dimorphos. The Hubble data was collected as part of Cycle 29 General Observers Program 16674.
“This is an unprecedented view of an unprecedented event,” summarized Andy Rivkin, DART investigation team lead of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
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).
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 and Webb science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.
Banner image: These images, Hubble on the left and Webb on the right, show observations of the Didymos-Dimorphos system several hours after NASA’s Double Asteroid Redirection Test (DART) intentionally impacted the moonlet asteroid. Credits: Science: NASA, ESA, CSA, Jian-Yang Li (PSI), Cristina Thomas (Northern Arizona University), Ian Wong (NASA-GSFC); image processing: Joseph DePasquale (STScI), Alyssa Pagan (STScI) Download full-resolution, uncompressed versions and supporting visuals from the Space Telescope Science Institute
Quelle: NASA
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Has Webb spotted the first stars?
Dense globular clusters in Webb’s First Deep Field image may contain the universe’s oldest and first stars
If you have never looked at the First Deep Field image captured by the James Webb Space Telescope, you need to.
Within the beautifully detailed image, you can see crowds of some of
the universe’s earliest galaxies, sparkling like jewels through the vast expanse of space and time.
Looking deeper into the image, a Canadian research team has discovered the most distant globular clusters ever identified, which may contain the first and oldest stars in the universe. Finding these is a task for which Webb was specifically built.
“Webb was built to find the first stars and the first galaxies and to help us understand the origins of complexity in the universe, such as the chemical elements and the building blocks of life,” says Lamiya Mowla, Dunlap Fellow at the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto and co-lead author of the study.
The researchers focussed on the Sparkler galaxy, known for the small yellow-red dot ‘sparkles’ of star clusters surrounding it. Five of the 12 ‘sparkles’ analysed turned out to be globular clusters, which are typically found in the bulge and the halo around galaxies and contain many old and red stars. Because they are so tightly-packed, these clusters are typically very stable and last for billions of years.
The find was made by the aptly named CANUCS: Canadian NIRISS Unbiased Cluster Survey.
The globular clusters were identified by the CANUCS team due to the lack of oxygen lines in the NIRISS (Near-Infrared Imager and Slitless Spectrograph) data.
The presence of oxygen is important. If detected, it would suggest the clusters were much younger and actively engaged in star formation.
JWST’s incredible resolution and sensitivity (and a fortunate natural magnification due to gravitational lensing by a foreground galaxy) allowed these ‘sparkles’ to be observed for the first time – something Hubble’s instruments (Webb’s predecessor) could never have been able to do. Using multiwavelength observations of the clusters, scientists can better model and understand their physical properties like age and the number of stars within it.
For globular clusters so distant and so old, this represents a chance to glimpse into the dressing room of the very early universe.
“These newly identified clusters were formed close to the first time it was even possible to form stars,” says Mowla. “Because the Sparkler galaxy is much farther away than our own Milky Way, it is easier to determine the ages of its globular clusters. We are observing the Sparkler as it was nine billion years ago, when the universe was only four-and-a-half billion years old.”
As Webb peers deeper into space, we can all expect to understand more about the origins of our universe, and ultimately ourselves, too
Originally published by Cosmos as Has Webb spotted the first stars?
Quelle: COSMOS
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Update: 2.10.2022
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'Shiny, sparkly object' in James Webb space image
President Biden applauds the unveiling of the very first full-colour image from James Webb
Astronomers have made a sparkling discovery in what was the very first full-colour image released from the new super space telescope James Webb.
The picture, presented to the world in July by US President Joe Biden, shows a fantastically deep view of the cosmos, billions of years into the past.
And it's in that remarkable vista that researchers have now picked out what they believe to be the most distant globular clusters ever identified.
Globulars are dense star collections.
What's more, these stars are generally really quite old and relatively pristine: they have fewer of the heavier chemical elements that taint more modern stars such as our Sun.
Our Milky Way Galaxy, in which our Sun lives, has more than 100 of these compact groupings littered around itself, but when and how they formed is still something of a puzzle.
The Biden Webb image should improve our understanding.
The picture, called SMACS 0723, is an example of what's referred to as a gravitational lens. It shows a set of massive foreground galaxies that have magnified and bent the light coming from galaxies in the background.And it's one particularly pretty galaxy in the far distance that's caught the eye of astronomers at the University of Toronto.
They've dubbed it "the Sparkler Galaxy" because it's surrounded by small yellow-red dots - by "sparkles".
Only with James Webb's extraordinary power are these dots resolvable. You couldn't see them with that other great observatory, Hubble, for instance.
The Toronto team wondered at first whether the sparkles were even associated with the Sparkler Galaxy. Was it possible they were just sitting out there on their own instead, a long way in front or behind the Sparkler? But it soon became obvious that they were associated because the Sparkler Galaxy itself is projected three times in the SMACS 0723 image.
That's just how gravitational lenses work sometimes: they can not only magnify background objects but also distort them and multiply their appearance.
And in each of the three versions of the Sparkler Galaxy, the same dots are present.
The team's contention is that the sparkles are globular clusters just like the globulars seen around our Milky Way today, except we're seeing these dots much, much earlier in the history of the Universe.
We see the Sparkler as it was nine billion years in the past, or about 4.5 billion years after the Big Bang.
"We are finding these globular clusters to be very massive," explained Dr Lamiya Mowla from Toronto's Dunlap Institute for Astronomy & Astrophysics. "We also find them to be very old.
"They could have formed in a burst at what we call 'cosmic noon', at the peak of star formation at about 10 billion years ago. But their colour isn't right. For something to be relatively young, it has to be bluer, and what we're finding is that they're much redder than we expected them to be, which means they must be older, even at that very early time," she told BBC News.
The team contends the stars in these globular sparkles probably formed just a few hundred million years after the Big Bang. It's even possible, the astronomers say, that the sparkles contain some of the very first stars ever to form in the Universe.
"They're the Holy Grail, right?" said Dr Mowla.
"Everyone is looking for those stars and when we first opened the SMACS image, we too were searching for the furthest stuff, the farthest things. And then we literally got sidetracked by the most shiny, sparkly object."
The Toronto research programme, called the CAnadian NIRISS Unbiased Cluster Survey (CANUCS), will now examine five more gravitationally lensed views from James Webb similar to its SMACS image.
"That's really going to push up the number of galaxies that we find with sparkles around them," said Dunlap Institute postdoctoral fellow Dr Kartheik Iyer.
"We want to know how ubiquitous these sparkles are. Did we just find a special galaxy or is this something we can expect to see more of when we have a representative sample from Webb," he told BBC News.
The Toronto Sparkler research is published in The Astrophysical Journal Letters.
James Webb Space Telescope and Hubble team up to peer through cosmic dust
The combination of the two telescopes' super powers reveals previously unseen features of a pair of distant galaxies.
Astronomers study how interstellar dust interferes with light from the simple elliptical galaxy on the left which is located farther away from Earth than the more intricate spiral galaxy on the right. (Image credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team)
Astronomers have combined observations from the James Webb and Hubble Space Telescopes to get a better grasp of how interstellar dust obscures the view of distant galaxies.
The newly released image, capturing two galaxies that appear close to each other, combines the infrared measurements taken by the James Webb Space Telescope with the visible and ultraviolet light imaging done by the Hubble Space Telescope.
In the image, the two galaxies known under the common name VV 191 appear to interact with each other, but they are actually quite distant. Light from the simple elliptical galaxy seen on the left of the image shines through the complex spiral galaxy on the right, which is located closer to Earth. The light from the background galaxy has to pass through the outer reaches of the spiral arms of the galaxy in the front, which can be distinguished in the image thanks to Webb's infrared vision. Features captured by Webb are represented by green, yellow and reddish hues in this image, while Hubble's observations are displayed in shades of blue.
"We got more than we bargained for by combining data from NASA's James Webb Space Telescope and NASA's Hubble Space Telescope!" Rogier Windhorst, an astronomer at Arizona State University and a lead author of the new research paper, said in a NASA statement(opens in new tab). "Webb's new data allowed us to trace the light that was emitted by the bright white elliptical galaxy, at left, through the winding spiral galaxy at right, and identify the effects of interstellar dust in the spiral galaxy."
Tracking the distribution of dust in galaxies helps astronomers understand how this dust alters the brightness and color of background objects, Windhorst added. Moreover, regions with high concentrations of dust and gas are likely areas where new stars and planets form, which makes them particularly attractive targets for astronomers.
When analyzing this image, astronomers made a bonus discovery: They found an unknown and very distant galaxy that was made visible thanks to the combination of Webb's observational superpowers and an effect known as gravitational lensing, by which extremely massive foreground objects bend light, acting like a magnifying glass for faint bodies in the background
Astronomers discovered a previously unknown galaxy thanks to the combination of James Webb Space Telescope's infrared vision and the effect known as gravitational lensing. (Image credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team)
The unknown galaxy, which has not yet been named, can be seen on the left of the white elliptical galaxy as an arced streak of orange light. In fact, the lensed galaxy is visible twice in this image, thanks to the duplicating effect that comes with gravitational lensing. The second apparition, however, is much harder to spot. The galaxy shines as a small, dim dot at 4 o'clock in the zoomed-in inset.
"These images of the lensed galaxy are so faint and so red that they went unrecognized in Hubble data, but are unmistakable in Webb's near-infrared image," Windhorst said in the statement. "Simulations of gravitationally lensed galaxies like this help us reconstruct how much mass is in individual stars, along with how much dark matter is in the core of this galaxy."
VV 191 was selected as a target for Webb's observations from about 2,000 galaxies found in Webb's images by citizen scientists as part of the Galaxy Zoo project. There is more that needs in-depth exploration in this image, Windhorst said. Spiral galaxies of different sizes and colors are scattered in the background, so astronomers have to do more work to understand how far away they are and how much dust they contain.
The observations were described in two as-yet unpublished papers that are available via the online repository Arxiv.
Quelle: SC