In new images from NASA’s James Webb Space Telescope to celebrate its fourth science anniversary, a familiar galaxy transforms into something far richer and far more complex than ever seen before. Webb’s unprecedented sensitivity across near- and mid-infrared wavelengths cuts through the thick lanes of dust that obscure Centaurus A’s center in visible light, showing a densely packed tapestry of individual stars and an active, ever-changing galaxy. These images mark four years of better-than-anticipated performance and successful science operations for the most powerful space telescope in history.
Centaurus A is 11 million light-years away from Earth, relatively close in cosmic terms. Yet, unlike most nearby galaxies, it is very active, making it a powerful laboratory for understanding how galaxies and black holes grow and evolve together.
At its core sits a supermassive black hole actively feeding on surrounding material. As it does, the black hole launches powerful jets and releases enormous amounts of energy, shaping the galaxy around it. At the same time, Centaurus A bears the scars of a dramatic past: a major collision with another galaxy roughly 2 billion years ago. The aftermath of that merger is still visible today in its unusual structure and ongoing star formation.
Visible-light observations from NASA’s Hubble Space Telescope could not reveal the central region where dust blocked the view, while NASA’s retired Spitzer Space Telescope revealed large-scale structures in the infrared without resolving individual stars. Now, Webb brings both clarity and depth, exposing the galaxy’s inner workings star by star.
“No single telescope tells the whole story,” said Shawn Domagal-Goldman, division director for astrophysics at NASA Headquarters in Washington. “Discoveries build over time, and new observatories expand on the foundations laid by earlier missions. Webb represents the most powerful step forward yet, opening a window into wavelengths and details never before accessible. This allows astronomers to examine structures and processes that other telescopes could not see.”
Dust, awe
Webb’s mid-infrared vision highlights the galaxy’s rich dust structures, which glow in intricate shapes that surprise and even perplex astronomers. A warped, parallelogram-like band cuts across the galaxy’s center, while wisps of material stretch outward like cosmic clouds.
An S-shaped feature, most notable in the image from Webb’s MIRI (Mid-Infrared Instrument), is also unusual and invites questions that need further study to answer. What created this shape? How does the black hole influence it? Is it influenced by merger-induced star formation?
Many of the glowing red points in the MIRI image are dust-rich stars or stellar nurseries, where aging stars are shedding material back into space or new stars are forming. This dust is the raw ingredient for future generations of stars and planets, making it central to the ongoing life cycle of the galaxy.
Written in its stars
With Webb’s high resolution, astronomers can now study Centaurus A star by star, even in its long-obscured central region. What looks grainy in the image from Webb, most obvious in the combined MIRI and NIRCam (Near-Infrared Camera) view, is actually a densely packed field of individual stars, together carrying information about the galaxy’s past.
With Webb’s view of Centaurus A, it becomes a case of galactic archaeology. Each star revealed helps reconstruct when different events happened: when older stars first formed, when activity slowed down, a burst of star formation during the collision, and stars born from gas stirred in its aftermath. Together, they form a timeline of the galaxy’s evolution.
Dynamic black hole
Webb’s capabilities go beyond imaging. By analyzing light with spectroscopy, astronomers can measure how gas moves within the galaxy.
Early findings from Webb show fast-moving ionized gas flowing outward, likely driven by the black hole’s activity, and warmer molecular hydrogen in a warped, rotating disk near the center. These observations help explore one of astronomy’s biggest questions: How does a black hole influence an entire galaxy?
The answer appears to be complex. The black hole can trigger star formation by compressing gas, but also limit it by pushing material away. Centaurus A offers a rare, nearby view of this cosmic interplay.
By tracing dust in never-before-seen detail, resolving millions of stars, and revealing the motion of gas near a supermassive black hole, Webb transforms Centaurus A into a vivid record of cosmic history.
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Webb uncovers dust-shrouded heart of Centaurus A after galaxy clash 2 billion years ago (2026, July 6)
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