Astronomers may have taken the closest step yet toward identifying the first stars born after the Big Bang. A new study led by Ari Visbal of the University of Toledo points to a distant galaxy, LAP1-B, as a strong candidate for hosting the universe’s earliest stellar generation, known as Population III stars.
These stars have never been observed directly. Scientists believe they were made only of hydrogen and helium — the raw elements formed in the Big Bang — with only traces of lithium. Heavier elements, called metals in astronomy, did not exist yet. That makes Population III stars different from every star seen today, including the Sun.
The stars are believed to have formed about 200 million years after the universe began. They burned out long ago, which is why astronomers search for their faint, ancient signatures instead of the stars themselves.
Why past candidates were ruled out
For decades, several possible detections have been proposed, but all failed to meet three core predictions. The first stars should form inside small dark-matter halos, consist of extremely massive stars, and appear only in small clusters. If any of these features are missing, the object is ruled out as a true Population III system.
The First Stars of the Universe Have Been Discovered
Astronomers from the University of Texas at Austin have discovered the galaxy GLIMPSE-16403, which may contain the first stars of the Universe — Population III. These ancient stars formed about 13 billion years ago, when space… pic.twitter.com/FivI3JeTU9
— Black Hole (@konstructivizm) March 12, 2025
New evidence points to LAP1-B
The new research, published in The Astrophysical Journal Letters, argues that LAP1-B is the first object to satisfy all three conditions. The team reports that the system formed inside a dark-matter halo with a mass of about 50 million Suns — almost exactly what theoretical models predict.
The stars themselves appear massive, ranging from 10 to 1,000 times the mass of the Sun. They are grouped in small clusters totaling only a few thousand solar masses, matching the expected formation pattern.
Gas around the system supports the finding
The gas surrounding LAP1-B contains almost no metals, a key indicator of a young, early-universe environment. The researchers say this likely reflects a moment just after the first stars exploded as supernovae, releasing the earliest heavy elements but not yet enriching the gas beyond trace levels.
Not confirmed yet, but a roadmap for future searches
The findings are not yet final. Key uncertainties remain, including how much material the first supernovae released and whether current computer models fully reflect the physics of the young universe. More data will be needed before LAP1-B can be confirmed as the home of the first stars.
Still, the detection marks a major step forward. The team used the James Webb Space Telescope along with gravitational lensing, which amplified the faint light from LAP1-B. Researchers say this method could now reveal more Big Bang–era systems hidden in deep space.
“LAP1-B may only represent the tip of the iceberg in terms of the study of Pop III stars with gravitational lensing from galaxy clusters,” the team wrote.
