Finally, the suspense is over. The James Webb Space Telescope is open for science! Today, in a massive joint conference with the ESA and CSA, NASA released the first science images from the fully operational JWST. Mission scientists chose these beauty shots as an ideal showcase of Webb’s tools and talents.
So, without further ado:
DEEP FIELD
“Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.” –Douglas Adams, The Hitch-Hiker’s Guide to the Galaxy
The first image, an ultra-deep-field snapshot of the galaxy cluster SMACS 0723, was presented by Jane Rigby of NASA’s Goddard Space Center. NASA officials revealed this very first inaugural image from the fully operational telescope to President Biden last night.
In a televised briefing to President Biden, NASA officials and Webb project scientists revealed this very first inaugural image from the James Webb space telescope.
Looking into the deep sky means looking back in time. And this is a deep dive indeed. In this image, we see the universe as it was, more than thirteen billion years ago. Distant galaxies become streaks and arcs across the sky, distorted by gravitational lensing.
But the image making headlines is only half the story. At left is what MIRI (Webb’s middle-infrared camera) sees; at right, NIRCam’s view of the same patch of sky. Notice the vivid reds and blues in the left-hand image. These celestial features shine in wavelengths of light too long for NIRCam to see. MIRI, however, can see them just fine.
The galaxies in this image appear as they were at about the same time that the Sun and our Earth formed. “There are galaxies here in which we’re seeing individual clusters of stars forming, popping up just like popcorn,” said Jane Rigby in this morning’s briefing. “And in the background, littered like jewels, are these faint red galaxies. That’s what we built the telescope to do. The most distant, we’re seeing as they looked thirteen billion years ago.”
Telescope Time
One of the biggest challenges for the team was playing schedule Tetris with the many astronomers and researchers asking for telescope time. Normally the pace of telescope observation is pretty sedate. Hubble would have taken weeks to produce a deep-field image like this. But what Hubble can do in weeks, Webb can do in hours. Compared to the status quo, “Webb took this image before breakfast,” said Rigby. It took just over twelve hours to get this deep-field portrait showing dozens of galaxies. That snappy pace means scientists can get a whole lot more done within their allotted time on the telescope.
Thankfully, however, we mere mortals are under no such time pressure. NASA has a deep-zoom feature, where you can explore this image at your leisure and spend as much time as you like, zooming in and playing around.
EXOPLANETS
The second image showed the water vapor that Webb sees in the steamy atmosphere of an exoplanet named WASP 96b.
Knicole Cólon detailed what Webb revealed about this nearby ‘hot Jupiter,’ perhaps a thousand light-years away. Data from ground-based telescopes had shown WASP 96b to be an unusually cloudless planet. But from space, Webb was able to discern clouds and weather patterns on the planet’s surface. Untroubled by Earth’s atmosphere, Webb can see the planet’s surface features with beautiful clarity.
James Webb: Open for Science, in Living Color
The JWST makes its observations in the infrared band of the EM spectrum. But because the infrared band has a longer wavelength than the visible spectrum, our eyes can’t perceive that light. So how do we turn that data into something the human eye can see and interpret?
“We’re basically translating light that we can’t see into light that we can see, by applying color, like red, green and blue, to the different filters we have from Webb,” explained Webb mission scientist Joe Depasquale. “The reason we do this is that you can get more information from the image if you can see it in color.”
“We take the shortest wavelengths of infrared light, and assign them blue colors, and then move our way down to green and red as we go to longer and longer wavelengths.”
Colorizing the images in this way reveals additional structures that look different at subtly different wavelengths of light. Using that additional data, astronomers can make more accurate observations and draw better conclusions.
“So, it’s a matter of picking and choosing filters and colors that enhance the details and the structure in the image itself,” added Webb image scientist Alyssa Pagan. “And then we additively combine those together to get our full-color image.”
STELLAR DEATH
Third is a glamour shot of a dying binary star, whose death throes created a planetary nebula called the Southern Ring. These two infrared images show the fiery end of the star’s life.
In the left-hand image, captured by Webb’s near-infrared NIRCam, you can see a lot of structure. First, there’s a series of concentric shells. These shells are created by “a dying star that has dispelled a large fraction of its mass in successive waves,” said Webb instrument scientist Karl Gordon. Then, there’s a bubbly, “foamy” orange visible throughout the nebula. The orange “foam” is molecular hydrogen, newly created and lit from within by the nebula’s expansion.
Moving inward, there’s a blue haze at the center of the nebula, which is ionized gas left over from the core of the star. It’s so hot that it’s emitting “well into the blue.” An edge-on galaxy with a bright center of mass stretches out toward the top left. And the rays of light visible, emanating from the center of the nebula, represent holes or gaps in the clouds that allow the star’s light to escape into space.
In the right-hand portrait, the one with the orange middle, the orange center represents longer-wavelength light that’s bright according to NIRCam, but dimmer to MIRI’s middle-infrared CCD. However, Gordon explained, the blue is actually from molecular hydrocarbon deposits on dust grains. Then, in the center, we can actually see both stars of the binary pair.
GALAXIES
Depicted here is a deep-sky feature called “Stefan’s Quintet,” a closely grouped cluster of five galaxies. The nearest galaxy in Stefan’s Quintet is the left-most galaxy as shown in this frame, and it lies about three hundred million light-years from us.
This is a near- and mid-infrared image, combined. Stars in the nearest galaxy actually resolve into point sources. In the others, gas and dust form star nurseries where stars are still being born today. Below the fiery arc, two galaxies have begun merging into one.
“If we strip away the near-infrared view of the stars, now in the mid-infrared with MIRI alone, we mostly see gas and dust,” said Mark McCaughrean, ESA senior advisor for Science and Exploration. “It’s the same galaxies again, with the two galaxies merging. But the top galaxy has something new and different in the middle of it…”
Giovanna Giardino, a Webb NIRspec specialist with the ESA, explained that in the top-most galaxy, the luminous center is actually the infrared glow from an active black hole. This cosmic monster outshines its host galaxy with the force of forty billion Suns. It’s invisible to the naked eye. But here, it blazes scarlet, lit by the infrared glow of the matter it’s devouring.
STELLAR BIRTH
Finally, we have this absolutely breathtaking picture of the Carina Nebula. It’s a star-forming region within our own galaxy, and it lies about 7600 light-years from Earth.
Amber Strong, Webb’s deputy project scientist, took us on a tour of the image. “This stunning vista of the ‘cosmic cliffs‘ of the Carina nebula reveals new details about this vast stellar nursery,” said Strong. “Today, for the first time, we’re seeing brand-new stars that were previously completely hidden from our view.”
Strong explained that the image shows “bubbles and cavities, and jets that are being blown out by these newborn stars. We even see some galaxies lurking in the background. We see structures that we don’t even know what they are!”
The image is a snapshot of a dynamic, ongoing process. Notice the brilliant stars near the top of the frame. (You can pick them out by their six-pointed halo, an artifact of Webb’s hexagonal mirrors.) The radiation and stellar wind from these gigantic, hot young stars are blowing a cosmic bubble, pressing against the gas and dust below.
Gas and dust make great raw material for newborn stars in stellar nurseries. But the same forces blowing the bubble can blow away the gas and dust in their turbulent wake. It’s a delicate balance, Strong added, where new stars are forming, but the rate of stellar formation is in decline.
Next Steps
So, what comes next for Webb? The telescope’s schedule is absolutely booked for the next full year. One key task for the telescope is investigating the “cosmic ladder,” which we use to determine distances in the deep sky. Webb will be closely observing Cepheid variable stars, AGNs, and other celestial features, to make the cosmic distance ladder more accurate.
If you’re wondering when we’ll finally point the JWST at a target inside the solar system, you’re in luck — we already have! There’s a massive data release coming Thursday, which will contain something like forty terabytes of images and raw data from Webb’s observations to date. In that data release, we’ll find images of Jupiter, along with other targets within our own star system.
Now that James Webb is open for science, astronomers will be pointing it at targets great and small. “One of Webb’s jobs is to find out about galaxies and help us to understand how they change,” said Katy Haswell, a Webb project scientist with the ESA. And as these images and others come to us, we’ll be combing through them, to bring you the very best.
Now Read:
- NASA Releases First Gorgeous Images as Webb Telescope Snaps Into Focus
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- The James Webb Space Telescope’s First Image Shows a Beautiful Expanse of Galaxies
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