NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA) have released the first set of full-color images taken by the James Webb Space Telescope — the world’s newest, most powerful, and largest space telescope. A total of five images were released, with the first image being unveiled by United States President Joe Biden and Vice President Kamala Harris at the White House the day before on July 11.
Five targets were selected by Webb’s science teams to be imaged and analyzed by Webb’s four instruments: MIRI (Mid-Infrared Imager), NIRCam (Near-Infrared Camera), NIRSpec (Near-Infrared Spectrometer), and the FGS/NIRISS (Fine Guidance Sensor and Near-Infrared Imager and Slitless Spectrograph). The five targets of the images were the Carina Nebula, WASP-96b, the Southern Ring Nebula, Stephan’s Quintet, and SMACS 0723.
“Webb’s First Deep Field” (SMACS 0723)
The first of five images to be revealed was the first deep field image taken by Webb, aptly named “Webb’s First Deep Field.” SMACS 0723 is the cosmic target focus of the image, which is the deepest and highest-resolution infrared image ever captured by a telescope. The image was the first to be released on July 11 and served as a preview of the other four images that were released the following day.
The image was taken using Webb’s Near-Infrared Camera, or NIRCam, which images objects in the near-infrared region of the electromagnetic spectrum. Webb’s Mid-Infrared Instrument, or MIRI, also imaged SMACS 0723 in the mid-infrared region of the spectrum. NIRCam took several images at different wavelengths, which were then stitched together to make the final composite image that was released on the 11th.
While the image, filled with bright stars and gorgeous galaxies of all shapes, sizes, and colors, may seem to take up a large portion of the sky, it’s only the size of a grain of sand held at arm’s length — taking up an incredibly small portion of the sky. What’s more, it only took Webb 12.5 hours to collect all the light needed to stitch together the final composite image. For comparison, it took the NASA/ESA Hubble Space Telescope 10 days to collect all the images needed to create its iconic “Hubble Deep Field” image from 1995.
SMACS 0723 is a galaxy cluster located approximately 4.35 billion light-years away from Earth. Due to its distance, we are seeing SMACS 0723 as it was many billions of years ago. Additionally, the overall combined mass of the galaxy cluster is enough to act as a gravitational lens, warping some of the light we see from the cluster and magnifying distant galaxies. This is why some of the galaxies in the image may appear warped or oddly shaped.
Due to the distances of some of the galaxies and other cosmic objects seen in this image, it can take the light from them billions of years to reach us. The expansion of the universe over time causes the light from these galaxies to be stretched into infrared wavelengths — becoming invisible to both visible and X-Ray telescopes like Hubble and Chandra. However, Webb is specifically designed to be an infrared telescope and can see the light from these distant galaxies, essentially allowing Webb to look back in time at some of the first galaxies that formed following the Big Bang.
Webb’s MIRI instrument also imaged SMACS 0723, showing many different colors and highlights where dust is located in the cluster. This dust is key to the formation of stars, which can ultimately lead to the formation of life. The blue-colored galaxies in the image above contain stars, but very small amounts of dust. The red-colored galaxies feature stars and large, thick layers of dust. Lastly, the green-colored galaxies are filled with chemical compounds like hydrocarbons. Understanding what galaxies are made of is key to researchers’ understanding of how galaxies form and evolve.
Lastly, Webb used its Near-Infrared Spectrometer (NIRSpec) and Near-Infrared Imager and Slitless Spectrograph (NIRISS) to collect spectra data on SMACS 0723. NIRSpec used its microshutter array to observe and collect data on 48 galaxies at once — a first for a space telescope and the first time this type of technology has been used in space.
The data from NIRSpec revealed that the light from one of the galaxies in the image traveled through space for 13.1 billion years before Webb’s mirrors caught it and imaged it. The overall age of the universe is estimated at 13.7 billion years.
Data collected by NIRISS showed that one of the galaxies in SMACS 0723 has a mirror image of itself.
Researchers plan to continue using Webb to research SMACS 0723 by analyzing the science collected for its first images, as well as possibly using the telescope to take longer exposures of the cluster — which will reveal more galaxies inside the cluster.
The next image to be released was the spectra data Webb collected on exoplanet WASP-96b.
While not an image of the exoplanet itself, the image released shows the spectral data Webb collected on the exoplanet, which is located around the class G star WASP-96 approximately 1,150 light-years away from Earth. The Webb data shows evidence of clouds and haze in WASP-96b’s atmosphere as well as a distinct water signature on the exoplanet.
Captured by Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) on June 21, 2022, the spectral data is the result of Webb’s NIRISS measuring light from the WASP-96 system for nearly seven hours as WASP-96b made a transit of the star.
When an exoplanet transits in front of its parent star, scientists can measure the differences in the star’s light caused by the exoplanet’s transit to determine the characteristics of the transiting exoplanet. For the WASP-96b data, NIRISS observed the light from WASP-96 as WASP-96b transited it and created a light curve, which shows how the light from WASP-96 changed over the observation period, and a transmission spectrum, which shows how abundant certain gases are on WASP-96b.
The light curve created from the WASP-96b transit confirms previous data collected by other observatories on WASP-96b’s existence, size, and orbit around WASP-96.
However, the transmission spectrum data revealed that the atmosphere of WASP-96b features a water signature, evidence of clouds (which were previously thought to not exist on WASP-96b), and indications of haze.
On the WASP-96b transmission spectrum created by NIRISS, the location and heights of peaks on the graph show scientists what compounds are present and how abundant they are on the exoplanet.
The WASP-96b spectral data collected by NIRISS is the most detailed near-infrared transmission spectrum data ever collected by a telescope. Additionally, NIRISS was able to measure and capture a very wide range of wavelengths in its data, including portions of the electromagnetic spectrum that have never been able to be measured by other telescopes (specifically any wavelengths longer than 1.6 microns).
Using the spectrum from NIRISS, scientists will be able to measure water vapor in WASP-96b’s atmosphere, determine the abundance of elements like carbon and oxygen, and estimate the temperature of the exoplanet’s atmosphere. Knowing these various characteristics will allow them to determine the overall make-up of WASP-96b as well as how it was born and evolved over time.
The WASP-96b spectral data was made by analyzing 280 individual spectra simultaneously over the 6.4-hour observation period, giving just a tiny look into what Webb can do when analyzing exoplanets. Throughout the next few months and years, scientists will use spectroscopy to investigate exoplanet surfaces, atmospheres, and more to gain a better understanding of planets and our solar system. In fact, nearly one-quarter of Webb’s first observation cycle is devoted to imaging exoplanets.
The Southern Ring Nebula
The third of the five images released was Webb’s image of the Southern Ring Nebula, or NGC 3132. The image was unveiled by members of the Webb science team at the Space Telescope Science Institute in Baltimore, Maryland.
Through the images taken by Webb’s NIRCam and MIRI instruments, scientists discovered that the star at the center of the nebula, which is approximately 2,500 light-years away, is covered in dust. The image from Webb shows the nebula face-on, with two stars at the center locked in a tight orbit. The ejection of stellar material from one of these stars (the dimmer of the two) is what created the nebula, and the stellar pair shape the stunning landscape of the nebula.
Webb’s new infrared pictures reveal details of the nebula and its core stars. The NIRCam image, which was taken in the near-infrared spectrum, shows the stars as a bright, prominent feature of the nebula. However, the image from Webb’s MIRI instrument, taken in the mid-infrared, shows the core stars as two separate objects, with the second star surrounded by dust.
This is the first time dust has been spotted surrounding the second star and shows that the brighter star is younger and still in an earlier stage of stellar evolution, likely meaning that the brighter star will eject its own planetary nebula sometime in the future.
While it slowly ages toward its eventual death, however, it will help influence the appearance of the Southern Ring Nebula. Each time the brighter and dimmer stars orbit one another, they stir around the gas and dust that make up the nebula, creating asymmetrical patterns in the nebula’s appearance and forming “shells” of gas and dust.
Each new shell that forms in the nebula represents an event where the fainter star lost a portion of its mass. So, the wider shells located at the outer reaches of the nebula are from when gas and dust were first ejected from the stars, and the tighter shells located closest to the stars are from the most recent ejections.
Additionally, in the NIRCam image, extremely fine rays of starlight from the central stars are located around the nebula. These rays of starlight stream out from the nebula where gaps and holes in the gas and dust are located, similar to how sunlight sometimes streams through gaps in clouds on Earth.
Each shell that the central stars shoot out gives scientists the chance to precisely measure gas and dust inside the nebula. These shells will eventually enrich the areas surrounding them and expand into the interstellar medium, which is the gas and dust present between stars, and travel through space for billions of years until it likely gets incorporated into a new star system or planet.
Astronomers will be able to dig deep into the characteristics of planetary nebulae like the Southern Ring Nebula using Webb’s immense power and capabilities of its instruments. Having an understanding of where and what molecules are present in nebulae will aid researchers in refining their knowledge of nebula.
The fourth image released was of Stephan’s Quintet, a group of five galaxies located in the Pegasus constellation. The image was released by members of the European Space Agency at the European Space Operations Centre in Darmstadt, Germany.
The image shows the swirling beauty of the five galaxies within the quintet in infrared. The five galaxies that make up Stephan’s Quintet are NGC 7317, NGC 7318a, NGC 7318b, NGC 7319, and NGC 7320c, with NGC 7320 being the brightest member of the visual group.
The image, a mosaic of over 150 million pixels and nearly 1,000 individual image files, is Webb’s largest image to date.
The quintet itself is comprised of only four galaxies that are actually compact, with the fifth, NGC 7320, being entirely separate from the group but caught in the visual view of the other four galaxies.
The four compact galaxies are NGC 7317, NGC 7318a, NGC 7318b, and NGC 7319 and are located approximately 290 million light-years from Earth – while NGC 7320 is located only 40 million light-years from Earth. Although these distances may seem far, the galaxies are actually relatively close to Earth in cosmic terms, with many galaxies being billions of light-years away rather than millions.
Many of the galaxies in the quintet are interacting and colliding with one another. Scientists rarely get to analyze galaxies this close to Earth in such extreme detail, especially the structures and characteristics of galaxies colliding. When analyzing the image above, scientists will be able to dissect the structures of the colliding galaxies, investigate how gas in the galaxies is being disturbed, and how interacting galaxies trigger star formation within each other.
Tight, interacting groups of galaxies like Stephan’s Quintet may have been a lot more common in the early universe when superheated, infalling material inside of galaxies may have fueled quasars, which are essentially extremely energetic black holes.
In fact, NGC 7319, which is the topmost galaxy in the quintet, features a supermassive black hole inside of its galactic nucleus, which is still active. This black hole is 24 million times the mass of our Sun and is as bright as 40 billion suns.
Using its NIRSpec and MIRI instruments, Webb imaged and studied NGC 7319’s galactic center in extreme detail. The instruments’ Integral Field Units (IFUs), which are a camera and a spectrograph combined into one system, gave the Webb science team a collection of images, known as a “data cube,” that highlight the spectral features of the galactic center.
IFUs give scientists the ability to separate the images for detailed study. One such image was of hot gas near the black hole, which allowed scientists to measure the velocity of bright outflows coming from the black hole.
A few galaxies over, at NGC 7320 (the leftmost galaxy in the quintet), Webb was able to individually resolve stars in the galaxy’s arms and bright central core.
The data Webb collected on Stephan’s Quintet will help scientists understand how black holes, specifically supermassive black holes, feed and grow and the rate at which they do so. Additionally, Webb’s images of Stephan’s Quintet are yet another display of Webb’s immense power and capabilities and show that Webb can view star-forming areas more directly and can investigate emissions from dust within galaxies.
“Cosmic Cliffs” (NGC 3324, the Carina Nebula)
The fifth and final image released was of a star-forming region within the Carina Nebula. The final image was unveiled at the Goddard Space Flight Center in Maryland by Webb’s deputy project scientist.
Titled “Cosmic Cliffs,” the image — which might be the most visually impressive Webb image thus far — showcases the true beauty of nebulae in infrared, with huge “mountains” and “valleys” of gas and dust that create a region with the perfect conditions for the birth of new stars.
The image shows the edge of a massive gaseous cavity, with some “peaks” of gas reaching incredible heights of nearly seven light-years. The massive wall of gas and dust seen in the center of the image has been cleared by extreme ultraviolet radiation and stellar wind from young stars that formed in the center of the large bubble-like, blue-colored area, which is above the area imaged by Webb.
These young stars are extremely massive and hot — creating the extreme radiation and wind that cleared the lower portions of the image. Specifically, the ultraviolet radiation produced by the stars is eroding the nebula’s wall, acting as a sort of sculptor by shaping the nebula wall into the “mountains” and “valleys” of gas and dust we see in the image. The blue-ish “steam” seen rising off of the nebula wall is hot, ionized gas and hot dust moving away from the nebula due to constant exposure to extreme radiation.
What’s more, the birth of new stars and stars hidden behind the walls of gas and dust are revealed using Webb’s infrared imaging capabilities. Before, many of the stars seen behind the gas and dust in this image could not be viewed because visible-light telescopes, like Hubble, can not see through the wall of dust and gas obscuring them.
The youngest stars in this image appear as red dots in the dusty areas of the nebula and feature protostellar jets that shoot out material from their formation. These very young stars that are undergoing the earliest and most rapid phases of star formation are often extremely difficult to capture, but Webb’s power, spatial resolution, imaging capabilities, and extreme sensitivity to infrared light allow it to capture these newborn stars in their earliest stages.
Webb’s observations and images will allow scientists to investigate the formation of stars in extreme detail. Star formation begins with the expansion of the nebula cavity and then propagates over time. As the ionized rim of the nebula pushes into the gas and dust, it can encounter unstable material. The interaction between the ionized gas and the unstable material will increase pressure and cause the material to collapse — forming a new star. However, this process can also prevent star formation from occurring due to the nebula wall being eroded by ultraviolet radiation.
One of Webb’s main objectives is to explore star formation and some of the most important questions surrounding it, including “what determines the number of stars that form in a certain region,” and “why do stars form with a certain mass?”
What’s more, Webb will investigate the impacts of star formation on giant clouds of gas and dust like nebulae. Currently, scientists don’t know that much about how low-mass stars affect these clouds. Low-mass stars are often more common than massive stars in cosmic clouds and can create narrow, opposing jets that inject large amounts of energy and momentum into nebulae and other clouds — reducing the nebular material needed for star formation.
Furthermore, with Webb, scientists will be able to investigate how these different star types influence nebulae and other cosmic clouds and will be able to determine an accurate number of stars and their types, allowing them to determine their effects on the clouds.
The image unveiled on Tuesday was taken using Webb’s NIRCam instrument. NIRCam helped reveal hundreds of new stars in NGC 3324 that were once hidden, as well as a few galaxies that were also hidden behind the wall of gas and dust. Webb teams also imaged NGC 3324 using MIRI and created a composite image of the nebula using both NIRCam and MIRI.
MIRI’s composite image showcases the protoplanetary disks — or the planet-forming disks surrounding stars where new exoplanets form — surrounding the stars in NGC 3324, appearing in bright pink and red in the mid-infrared. Additionally, MIRI’s images unveil structures hidden inside the dust and reveal the sources of the massive jets and outflows seen in the NIRCam image.
NGC 3324 is located approximately 7,600 light-years away in the northwestern corner of the larger Carina Nebula (NGC 3372). The Carina Nebula is located in the Carina constellation and is home to other famous cosmic objects, such as the Keyhole Nebula and Eta Carinae, an unstable supergiant star.
(Lead image: “Cosmic Cliffs” — NGC 3324, a star-forming region of the Carina Nebula, as imaged by the James Webb Space Telescope’s NIRCam instrument. Credit: NASA/ESA/CSA/STScI)