Plate Nº 55 · recorded October 10, 2026
Space & AstronomyReported finding
Webb Telescope Magnifies Galaxies 300-Fold in Cosmic Cluster Image
James Webb's September 2026 Picture of the Month shows galaxy cluster MACS J0454.1-0300 bending light from galaxies seen roughly 800 million years after the Big Bang. Some clumps are magnified more than 300 times.
By Marcus Bennett3 min read507 words
In brief
- Light from galaxy cluster MACS J0454.1-0300 has traveled about 8 billion years to reach Earth.
- Webb magnified some clumps within the lensed arcs by more than a factor of 300.
- Bright knots within the arcs correspond to physical regions just 5 light-years across.
- The image includes a galaxy from roughly 800 million years after the Big Bang and a merging group from about 2 billion years after.
- A 2014 Hubble image of the same cluster missed hundreds of galaxies that Webb's infrared view reveals.
A galaxy cluster 8 billion light-years away has stretched and multiplied the light of galaxies from the early universe, producing arcs and smears in a new James Webb Space Telescope image that magnifies some clumps by more than 300 times.
The NASA/ESA/CSA James Webb Space Telescope Picture of the Month, released in September 2026, centers on MACS J0454.1-0300. An ESA Webb description likens the scene to galaxies that "have stepped into a house of mirrors." Most of what looks like stretching is actually light from galaxies far behind the cluster, bent into long arcs by the cluster's gravity.
How does gravity act like a lens?
Gravitational lensing happens when a massive foreground object warps the path of light from objects behind it. The cluster acts like an uneven magnifying glass: its gravity bends light rays, stretching background galaxy images into long arcs around the cluster's edge. ESA describes the distorted shapes as appearing "like a painting smeared by a giant hand."
Most of the orange smears stretching around the cluster are not cluster members at all. They are far more distant galaxies whose light has been bent en route to Earth. The technique lets astronomers see structures otherwise too faint or small to detect, including star clusters and individual stars in the early universe.
How far back does the image reach?
Webb resolved two lensed regions at very different distances:
- A galaxy group from about 2 billion years after the Big Bang, caught mid-merger and producing an enormous burst of star formation
- A single galaxy from roughly 800 million years after the Big Bang
Astronomers also pinpointed bright knots within the lensed arcs corresponding to physical regions just 5 light-years across, roughly the size of a small star cluster. Without the natural magnification, those structures would be invisible.
What did Webb find that Hubble missed?
A NASA/ESA Hubble Space Telescope image of the same cluster was released in 2014. The new Webb image reveals hundreds of additional galaxies. Those galaxies "were there all along," according to ESA, but Webb detects much redder wavelengths than Hubble.
That sensitivity advantage matters most for distant, dusty, or ancient systems whose light has stretched, or redshifted, into the infrared over billions of years of cosmic expansion. In the image, blue-white smudges are typically nearer stars or galaxies whose light has not yet shifted toward redder wavelengths. Gold and orange objects tend to be more distant cluster members or stretched background galaxies.
Why study this cluster?
The data come from two approved Webb observing programs:
- Program #5058, led by Furtak
- Program #6882, led by Fujimoto
Both programs exploit massive galaxy clusters as natural magnifiers to bring faint, distant targets into view, an approach often called the cluster-lens technique. Studying ancient galaxies through these natural lenses gives researchers a window into the first generations of stars and addresses how quickly structures grew in the first billion years after the Big Bang.
The full image is available on ESA's Webb website.
via esawebb.org (Original)
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