What looks much like craggy mountains on a moonlit evening is actually the edge of a nearby, young, star-forming region NGC 3324 in the Carina Nebula. Captured in infrared light by the Near-Infrared Camera (NIRCam) on NASA’s James Webb Space Telescope, this image reveals previously obscured areas of star birth.  Called the Cosmic Cliffs, the region is actually the edge of a gigantic, gaseous cavity within NGC 3324, roughly 7,600 light-years away. The cavernous area has been carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely massive, hot, young stars located in the center of the bubble, above the area shown in this image. The high-energy radiation from these stars is sculpting the nebula’s wall by slowly eroding it away.    NIRCam – with its crisp resolution and unparalleled sensitivity – unveils hundreds of previously hidden stars, and even numerous background galaxies. Several prominent features in this image are described below.  • The “steam” that appears to rise from the celestial “mountains” is actually hot, ionized gas and hot dust streaming away from the nebula due to intense, ultraviolet radiation.   • Dramatic pillars rise above the glowing wall of gas, resisting the blistering ultraviolet radiation from the young stars.  • Bubbles and cavities are being blown by the intense radiation and stellar winds of newborn stars.  • Protostellar jets and outflows, which appear in gold, shoot from dust-enshrouded, nascent stars.  • A “blow-out” erupts at the top-center of the ridge, spewing gas and dust into the interstellar medium.   • An unusual “arch” appears, looking like a bent-over cylinder.  This period of very early star formation is difficult to capture because, for an individual star, it lasts only about 50,000 to 100,000 years – but Webb’s extreme sensitivity and exquisite spatial resolution have chronicled this rare event.  Located roughly 7,600 light-years away, NGC 3324 was first catalogued by James Dunlop in 1826. Visible from the Southern Hemisphere, it is located at the northwest corner of the Carina Nebula (NGC 3372), which resides in the constellation Carina. The Carina Nebula is home to the Keyhole Nebula and the active, unstable supergiant star called Eta Carinae.   NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center.
James Webb Space Telescope NIRCam Image of the “Cosmic Cliffs” in Carina Nebula
Thousands of galaxies flood this near-infrared image of galaxy cluster SMACS 0723. High-resolution imaging from NASA’s James Webb Space Telescope combined with a natural effect known as gravitational lensing made this finely detailed image possible.  First, focus on the galaxies responsible for the lensing: the bright white elliptical galaxy at the center of the image and smaller white galaxies throughout the image. Bound together by gravity in a galaxy cluster, they are bending the light from galaxies that appear in the vast distances behind them. The combined mass of the galaxies and dark matter act as a cosmic telescope, creating magnified, contorted, and sometimes mirrored images of individual galaxies.  Clear examples of mirroring are found in the prominent orange arcs to the left and right of the brightest cluster galaxy. These are lensed galaxies – each individual galaxy is shown twice in one arc. Webb’s image has fully revealed their bright cores, which are filled with stars, along with orange star clusters along their edges.  Not all galaxies in this field are mirrored – some are stretched. Others appear scattered by interactions with other galaxies, leaving trails of stars behind them.  Webb has refined the level of detail we can observe throughout this field. Very diffuse galaxies appear like collections of loosely bound dandelion seeds aloft in a breeze. Individual “pods” of star formation practically bloom within some of the most distant galaxies – the clearest, most detailed views of star clusters in the early universe so far.  One galaxy speckled with star clusters appears near the bottom end of the bright central star’s vertical diffraction spike – just to the right of a long orange arc. The long, thin ladybug-like galaxy is flecked with pockets of star formation. Draw a line between its “wings” to roughly match up its star clusters, mirrored top to bottom. Because this galaxy is so magnified and its individual star clusters are so crisp, researchers will be able to study it in exquisite detail, which wasn’t previously possible for galaxies this distant.  The galaxies in this scene that are farthest away – the tiniest galaxies that are located well behind the cluster – look nothing like the spiral and elliptical galaxies observed in the local universe. They are much clumpier and more irregular. Webb’s highly detailed image may help researchers measure the ages and masses of star clusters within these distant galaxies. This might lead to more accurate models of galaxies that existed at cosmic “spring,” when galaxies were sprouting tiny “buds” of new growth, actively interacting and merging, and had yet to develop into larger spirals. Ultimately, Webb’s upcoming observations will help astronomers better understand how galaxies form and grow in the early universe.  NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center.  For a full array of Webb’s first images and spectra, including downloadable files, please visit: https://webbtelescope.org/news/first-images
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This side-by-side comparison shows observations of the Southern Ring Nebula in near-infrared light, at left, and mid-infrared light, at right, from NASA’s Webb Telescope.  This scene was created by a white dwarf star – the remains of a star like our Sun after it shed its outer layers and stopped burning fuel though nuclear fusion. Those outer layers now form the ejected shells all along this view.  In the Near-Infrared Camera (NIRCam) image, the white dwarf appears to the lower left of the bright, central star, partially hidden by a diffraction spike. The same star appears – but brighter, larger, and redder – in the Mid-Infrared Instrument (MIRI) image. This white dwarf star is cloaked in thick layers of dust, which make it appear larger.   The brighter star in both images hasn’t yet shed its layers. It closely orbits the dimmer white dwarf, helping to distribute what it’s ejected.  Over thousands of years and before it became a white dwarf, the star periodically ejected mass – the visible shells of material. As if on repeat, it contracted, heated up – and then, unable to push out more material, pulsated. Stellar material was sent in all directions – like a rotating sprinkler – and provided the ingredients for this asymmetrical landscape.  Today, the white dwarf is heating up the gas in the inner regions – which appear blue at left and red at right. Both stars are lighting up the outer regions, shown in orange and blue, respectively.  The images look very different because NIRCam and MIRI collect different wavelengths of light. NIRCam observes near-infrared light, which is closer to the visible wavelengths our eyes detect. MIRI goes farther into the infrared, picking up mid-infrared wavelengths. The second star more clearly appears in the MIRI image, because this instrument can see the gleaming dust around it, bringing it more clearly into view.  The stars – and their layers of light – steal more attention in the NIRCam image, while dust plays the lead in the MIRI image, specifically dust that is illuminated.   Peer at the circular region at the center of both images. Each contains a wobbly, asymmetrical belt of material. This is where two “bowls” that make up the nebula meet. (In this view, the nebula is at a 40-degree angle.) This belt is easier to spot in the MIRI image – look for the yellowish circle – but is also visible in the NIRCam image.  The light that travels through the orange dust in the NIRCam image – which look like spotlights – disappear at longer infrared wavelengths in the MIRI image.  In near-infrared light, stars have more prominent diffraction spikes because they are so bright at these wavelengths. In mid-infrared light, diffraction spikes also appear around stars, but they are fainter and smaller (zoom in to spot them).  Physics is the reason for the difference in the resolution of these images. NIRCam delivers high-resolution imaging because these wavelengths of light are shorter. MIRI supplies medium-resolution imagery because its wavelengths are longer – the longer the wavelength, the coarser the images are. But both deliver an incredible amount of detail about every object they observe – providing never-before-seen vistas of the universe.  For a full array of Webb’s first images and spectra, including downloadable files, please visit: https://webbtelescope.org/news/first-images   NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center.  MIRI was contributed by ESA and NASA, with the instrument designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.
James Webb Space Telescope Southern Ring Nebula (NIRCam and MIRI Images Side by Side)
A transmission spectrum made from a single observation using Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) reveals atmospheric characteristics of the hot gas giant exoplanet WASP-96 b.    A transmission spectrum is made by comparing starlight filtered through a planet’s atmosphere as it moves across the star, to the unfiltered starlight detected when the planet is beside the star. Each of the 141 data points (white circles) on this graph represents the amount of a specific wavelength of light that is blocked by the planet and absorbed by its atmosphere.   In this observation, the wavelengths detected by NIRISS range from 0.6 microns (red) to 2.8 microns (in the near-infrared). The amount of starlight blocked ranges from about 13,600 parts per million (1.36 percent) to 14,700 parts per million (1.47 percent).  Researchers are able to detect and measure the abundances of key gases in a planet’s atmosphere based on the absorption pattern – the locations and heights of peaks on the graph: each gas has a characteristic set of wavelengths that it absorbs. The temperature of the atmosphere can be calculated based in part on the height of the peaks: a hotter planet has taller peaks. Other characteristics, like the presence of haze and clouds, can be inferred based on the overall shape of different portions of the spectrum.    The gray lines extending above and below each data point are error bars that show the uncertainty of each measurement, or the reasonable range of actual possible values. For a single observation, the error on these measurements is remarkably small.  The blue line is a best-fit model that takes into account the data, the known properties of WASP-96 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere. Researchers can vary the parameters in the model – changing unknown characteristics like cloud height in the atmosphere and abundances of various gases – to get a better fit and further understand what the atmosphere is really like. The difference between the best-fit model shown here and the data simply reflects the additional work to be done in analyzing and interpreting the data and the planet.   Although full analysis of the spectrum will take additional time, it is possible to draw a number of preliminary conclusions. The labeled peaks in the spectrum indicate the presence of water vapor. The height of the water peaks, which is less than expected based on previous observations, is evidence for the presence of clouds that suppress the water vapor features. The gradual downward slope of the left side of the spectrum (shorter wavelengths) is indicative of possible haze. The height of the peaks along with other characteristics of the spectrum is used to calculate an atmospheric temperature of about 1350°F (725°C).    This is the most detailed infrared exoplanet transmission spectrum ever collected, the first transmission spectrum that includes wavelengths longer than 1.6 microns with such high resolution and accuracy, and the first to cover the entire wavelength range from 0.6 microns (visible red light) to 2.8 microns (near-infrared) in a single shot. The speed with which researchers have been able to make confident interpretations of the spectrum is further testament to the quality of the data.   The observation was made using NIRISS’s Single-Object Slitless Spectroscopy (SOSS) mode, which involves capturing the spectrum of a single bright object, like the star WASP-96, in a field of view.   WASP-96 b is a hot gas giant exoplanet that orbits a Sun-like star roughly 1,150 light-years away, in the constellation Phoenix. The planet orbits extremely close to its star (less than 1/20th the distance between Earth and the Sun) and completes one orbit in less than 3½ Earth-days. The planet’s discovery, based on ground-based observations, was announced in 2014. The star, WASP-96, is somewhat older than the Sun, but is about the same size, mass, temperature, and color.  The background illustration of WASP-96 b and its star is based on current understanding of the planet from both NIRISS spectroscopy and previous ground- and space-based observations. Webb has not captured a direct image of the planet or its atmosphere.  NIRISS was contributed by the Canadian Space Agency. The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.
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