Astronomers utilizing the NASA/ESA/CSA James Webb Space Telescope have identified the chemical signature of a protostar with a mass between 1,000 and 10,000 times that of the Sun in GS 3073, an early galaxy with a redshift of 5.55 (approximately 1 billion years post-Big Bang).
In 2022, it was suggested by astronomers that supermassive stars formed naturally within turbulent flows of rare cold gas during the early universe, thus accounting for the existence of quasars less than a billion years after the Big Bang.
“Our recent finding helps to unravel a cosmic enigma that has persisted for two decades,” stated Dr. Daniel Whalen of the University of Portsmouth.
“GS 3073 offers the first observational proof of these colossal stars.”
“These astronomical behemoths would have radiated intensely for a brief period before collapsing into enormous black holes, leaving behind chemical imprints detectable billions of years later.”
“Much like Earth’s dinosaurs, they were massive and rudimentary, with lifespans spanning just 250,000 years—an ephemeral moment in cosmic time.”
The cornerstone of this discovery involved assessing the nitrogen-to-oxygen ratio in the GS 3073 galaxy.
This galaxy presents a nitrogen-to-oxygen ratio of 0.46, significantly exceeding what can be accounted for by any known type of star or stellar explosion.
“Chemical abundances serve as the universe’s fingerprints, and the pattern from GS 3073 is unlike that produced by typical stars,” remarked Dr. Devesh Nandal, an astronomer at the University of Virginia, Harvard University, and the Smithsonian Center for Astrophysics.
“This unprecedented nitrogen concentration aligns with a single known source: protostars that are thousands of times more massive than the Sun.”
“This suggests that the first generation of stars included genuine supermassive objects that contributed to the creation of early galaxies and may have planted the seeds for contemporary supermassive black holes.”
The researchers performed modeling of stars with masses between 1,000 and 10,000 solar masses to predict their evolution and the elements they would produce.
They identified a specific mechanism for generating substantial nitrogen. (i) These colossal stars fuse helium, forming carbon in their cores. (ii) Carbon seeps into the outer shell, where hydrogen is undergoing fusion. (iii) Carbon merges with hydrogen, resulting in nitrogen through the carbon/nitrogen/oxygen (CNO) cycle. (iv) Convection disseminates nitrogen throughout the star. (v) Eventually, this nitrogen-rich material is expelled into space, enriching the surrounding gas.
This mechanism spans millions of years during the star’s helium burning phase, leading to the excess nitrogen observed in GS 3073.
The team’s models predict that upon demise, these massive stars do not explode. Instead, they collapse directly into gigantic black holes with masses reaching thousands of solar masses.
Interestingly, GS 3073 harbors an actively feeding black hole at its core, which could potentially be the remnant of one of these supermassive first stars.
If validated, this would simultaneously clarify two mysteries: the origin of nitrogen and the formation of black holes.
The study also revealed that this nitrogen signature is exclusive to specific mass ranges.
“Stars below 1,000 solar masses or above 10,000 solar masses do not generate chemical patterns suitable for this signature, indicating a ‘sweet spot’ for such enrichment,” scientists noted.
of study Published in Astrophysics Journal Letter.
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Devesh Nandal others. 2025. A protostar between 1000 and 10,000 MSun created a nitrogen surplus in GS 3073 at z = 5.55. APJL 994, L11; doi: 10.3847/2041-8213/ae1a63
Source: www.sci.news
