Scientists report first direct evidence of ‘monster stars’ from the cosmic dawn

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Scientists report first direct evidence of ‘monster stars’ from the cosmic dawn
Mrigakshi Dixit
Wed, December 10, 2025 at 5:04 AM EST
3 min read





The James Webb Space Telescope (JWST) has found compelling evidence for "monster stars" — gigantic, primordial stars that existed in the early universe.

For almost 20 years, one of the universe's greatest mysteries has perplexed astronomers: How did supermassive black holes grow so large, so fast, in the cosmic blink of an eye after the Big Bang?

Normal mass stars didn't have the time to produce such behemoths, just less than a billion years after the Big Bang.

An international research team led by the Center for Astrophysics | Harvard & Smithsonian in the US used the powerful Webb telescope to finally uncover the missing link.

Webb data revealed chemical fingerprints of the long-theorized monster stars that served as the necessary seeds.

“Our latest discovery helps solve a 20-year cosmic mystery. With GS 3073 [galaxy], we have the first observational evidence that these monster stars existed,” said Daniel Whalen from the University of Portsmouth's Institute of Cosmology and Gravitation on December 9.


Giants with short lives

In the early universe, the monster stars burned their fuel at an incredible rate. They lived for just a quarter of a million years — a short, brilliant existence before their inevitable collapse into massive black holes. The collapse left detectable chemical signatures that persist for billions of years.

The evidence came from examining the chemical signatures in a galaxy named GS 3073.

Researchers focused on its elemental composition. What they found defied all conventional models.

The galaxy exhibited an "extreme imbalance" between nitrogen and oxygen, with a ratio of 0.46.

Surprisingly, this value is far higher than any known star type or even stellar explosion can produce in the early universe. According to the team, the pattern matched only one theoretical source: stars weighing between 1,000 and 10,000 times the mass of our Sun.

“Chemical abundances act like a cosmic fingerprint, and the pattern in GS 3073 is unlike anything ordinary stars can produce. This tells us the first generation of stars included truly supermassive objects that helped shape the early galaxies and may have seeded today’s supermassive black holes,” said Devesh Nandal, a Swiss National Science Foundation postdoctoral fellow at the CfA's Institute for Theory and Computation.


Seed of the 'monster'

The research details a specific process for nitrogen production.

These stars burn helium to create carbon; that carbon then leaks into a hydrogen-burning shell, where the carbon-nitrogen-oxygen (CNO) cycle produces large amounts of nitrogen, which is eventually shed into space.

The nitrogen excess seen in GS 3073 is created because this process continues for millions of years while the star is in its helium-burning phase.

Modelling showcased that these monster stars do not explode like a typical supernova. They immediately transform into massive black holes.

These black holes, weighing thousands of solar masses, provided the perfect "seed" for the eventual growth of the supermassive black holes observed today.

Notably, GS 3073 itself hosts an actively feeding black hole at its center. The team is questioning whether this could be the remnant of one of these massive first stars.

This finding opens a dazzling new window into the "cosmic Dark Ages." This was the epoch when the first stars ignited, beginning the transformation of the universe's simple hydrogen-and-helium chemistry into the rich elemental mix we see today.

Researchers predict JWST will find many more galaxies with this distinct nitrogen signature, turning a decades-old theory into confirmed cosmic history.

The study was published in the Astrophysical Journal Letters.


https://www.yahoo.com/news/articles/scientists-report-first-direct-evidence-100449352.html