Washington, D.C. | Dec 02, 2025

NASA scientists may have detected the oldest stars in the universe, formed shortly after the Big Bang, using the James Webb Space Telescope (JWST). These stars, known as Population III or Pop III stars, were observed in the galaxy LAP1-B, located approximately 13 billion light-years from Earth, according to a study published in The Astrophysical Journal Letters.

The research team, led by astronomer Eli Visbal, identified these primordial stars through JWST’s infrared spectrum, which revealed intense ultraviolet light emissions. The stars are estimated to be roughly 100 times the mass of the Sun. The team highlighted that LAP1-B meets the three theoretical conditions required for Pop III star formation. These include a low-metallicity environment, predominantly consisting of hydrogen and helium, low-mass star clusters with only a few extremely massive stars, and alignment with the initial mass function predicted by stellar formation models.

Visbal explained that detecting Pop III stars required not only JWST’s high sensitivity but also gravitational lensing, where the light from LAP1-B was magnified by a massive galaxy cluster between it and Earth. This combination allowed astronomers to observe details that were previously impossible to detect.

Pop III stars are believed to be the first generation of stars, formed when hydrogen and helium combined with dark matter. These stars were enormous, with masses potentially millions of times that of the Sun and luminosities billions of times brighter. Studying them offers a glimpse into the earliest stages of the universe, helping astronomers understand how the first galaxies and cosmic structures evolved.

“These stars could be the building blocks of larger galaxies,” Visbal noted. “Observing them allows us to study the universe’s first cosmic systems and trace how matter organized itself after the Big Bang.” The team plans to conduct hydrodynamical simulations to examine the transition from Pop III to Pop II stars, which are the universe’s second generation of stars. This will help confirm if the LAP1-B spectrum matches theoretical expectations for early star clusters.

Researchers also pointed out that LAP1-B might only be the tip of the iceberg. Gravitational lensing from other galaxy clusters may reveal many more Pop III stars in the universe, providing deeper insight into the formation and evolution of the earliest stars.

The potential discovery marks a significant milestone in understanding the universe’s origins, offering a rare opportunity to directly study the first luminous objects that shaped the cosmic landscape. With continued observations, astronomers hope to map how these ancient stars influenced the development of galaxies and contributed to the evolution of the universe as we see it today.

The findings demonstrate the power of JWST and modern astrophysics in pushing the boundaries of human knowledge, making it possible to observe stars that formed over 13 billion years ago, a period just a few hundred million years after the Big Bang.

 NASA’s James Webb Space Telescope May Have Spotted the Universe’s Oldest Stars Formed After the Big Bang

NASA’s James Webb Space Telescope (JWST) may have detected the oldest stars ever formed, appearing shortly after the Big Bang. These stars, called Population III (Pop III) stars, were observed in the galaxy LAP1-B, located 13 billion light-years away, according to a study published in The Astrophysical Journal Letters.

A team led by astronomer Eli Visbal reported that JWST’s infrared spectrum revealed these stars emitting intense ultraviolet light and estimated to be about 100 times the mass of the Sun. LAP1-B meets the theoretical conditions for Pop III star formation: a low-metallicity environment, small clusters of massive stars, and alignment with the initial mass function.

Detecting Pop III stars required JWST’s sensitivity combined with gravitational lensing, where a galaxy cluster magnified the light from LAP1-B. These stars are considered the first generation of stars, forming from hydrogen and helium combined with dark matter. They were extremely massive and bright, laying the foundation for early galaxies.

Visbal explained that these stars could help astronomers understand how the first cosmic systems formed. The team will run simulations to study the transition from Pop III to Pop II stars. LAP1-B might represent just the tip of the iceberg, with more Pop III stars likely detectable through gravitational lensing, offering insights into the earliest stages of the universe.