This baby galaxy is a ‘missing link’ in the quest to glimpse the universe’s first stars

May 13, 2026

5 min read

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This baby galaxy is a ‘missing link’ in the quest to glimpse the universe’s first stars

Seen just 800 million years after the big bang, an object called LAP1-B is a galactic building block that seems to hold some of the first stars to ever shine

By Lee Billings edited by Jeanna Bryner

Galaxy cluster MACS J0416 magnifies the light from more distant background galaxies through gravitational lensing.

NASA/ESA/CSA/STScI/J. Diego/Instituto de Física de Cantabria/J. D’Silva/University of Western Australia/A. Koekemoer/STScI/J. Summers/Arizona State University/R. Windhorst/Arizona State University/H. Yan/University of Missouri

It’s a discovery so rich with mind-bending ideas that it seems straight from science fiction: Using humanity’s biggest off-world observatory to focus on a tiny, faraway arc of light magnified by a quirk of spacetime, astronomers have glimpsed a faint galaxy as it was 13 billion years ago, when it was brimming with dark matter—as well as what may be fresh ashes from the universe’s earliest, strangest stars.

The small, faraway galaxy is named LAP1-B, the observatory is NASA’s James Webb Space Telescope (JWST), and the strange stars would have been members of what astronomers call “Population III”—titanic suns that burned bright and died young close to the dawn of time.

Such stars are the quarry that JWST was designed for—stellar orbs composed of pristine, primordial hydrogen and helium gas that were summoned into being by the big bang. These stars are not quite the stuff that most cosmologists’ dreams are made of but rather the sources for the atoms that made cosmologists themselves. The oxygen in your lungs, the iron in your blood, the calcium in your bones, the carbon in your cells, and even the silicon in your smartphone can all be traced back to Population III stars, which blasted out heavy-metal cosmic fertilizer (astronomers call all heavier-than-helium elements “metals”) upon their explosive deaths. The debris from their demise coalesced to form subsequent stellar generations—Population II and Population I stars—plus planets and eventually people.

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That’s the creation story astronomers tell themselves, anyway. The trouble with proving all of its details has been that these first stars are so distant in space and time that even the mighty JWST has yet to directly, definitively see them. Instead telltale hints of their existence primarily show up in studies of galaxies that are big and bright enough for JWST to see clear across the universe. Rather than gathering Population III stars’ light, JWST so far has only inferred their presence in such places via incandescent fogs that are eerily lit from within by the first stars’ intense radiation.

LAP1-B is different. It’s a wisp of glowing gas nestled in a pool of invisible dark matter, a “cosmic fossil” seen a mere 800 million years after the big bang yet resembling the swarms of “ultrafaint dwarf galaxies” (UFDs) astronomers find near our Milky Way. Cosmologists suspect that, in the early universe, such objects were like puzzle pieces, assembling into bigger galaxies; the UFDs we see around us today are part of a larger population of leftover scraps scattered throughout the cosmos that never found a larger home. JWST’s ability to see LAP1-B at all is only because of the galaxy’s fortuitous placement behind a cosmic behemoth called MACS J0416, a giant galaxy cluster that is so immense that its mass warps spacetime to create a “gravitational lens” that boosts LAP1-B’s feeble light 100-fold.

Ironically, this boost is so great that JWST, custom-built for the task of finding things like LAP1-B, didn’t discover it. Instead the object was first announced in 2020 from data gathered with a ground-based facility, the European Southern Observatory’s Very Large Telescope in Paranal, Chile, which had been following up on earlier Hubble Space Telescope studies of MACS J0416. Subsequent studies with JWST have progressively revealed more about this mysterious object. The latest, published in Nature today, strengthens the case that LAP1-B is a newborn cosmic puzzle piece packed with material freshly manufactured by Population III stars.

A false-color image of a portion of the MACS J0416 galaxy cluster as seen at multiple infrared wavelengths by NASA’s James Webb Space Telescope (JWST). The “cosmic fossil” LAP1-B—a small, faint background galaxy magnified into view by the gravitational lensing of