The James Webb Space Telescope

[pinball1970]

Pre print on MoM-z14

https://arxiv.org/abs/2505.11263

Article here

https://phys.org/news/2026-01-webb-boundaries-universe-closer-big.html

 

[Astronuc]

An article on giant (or monster) stars came to my attention. Astronomers have been looking at system GS 3073 with the JWST.

Cambridge, MA (December 9, 2025)— For two decades, astronomers have puzzled over how supermassive black holes, which are some of the brightest objects in the universe, could exist less than a billion years after the Big Bang. Normal stars simply couldn't create such massive black holes quickly enough.

Now, using NASA’s James Webb Space Telescope (JWST), an international team of astronomers has found the first compelling evidence that solves this cosmic mystery: “monster stars” weighing between 1,000 and 10,000 times the mass of our Sun existed in the early universe. The breakthrough came from examining chemical signatures in a galaxy called GS 3073.

A new study led by scientists from the Center for Astrophysics | Harvard & Smithsonian (CfA) and the University of Portsmouth in England has discovered an extreme imbalance of nitrogen to oxygen that cannot be explained by any known type of star.

In 2022, researchers published work in Nature predicting that supermassive stars naturally formed in rare, turbulent streams of cold gas in the early universe, explaining how quasars (extraordinarily bright black holes) could exist less than a billion years after the Big Bang.

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

Turbulent cold flows gave birth to the first quasars (Nature, 2022)​

https://www.nature.com/articles/s41586-022-04813-y

The key to the discovery was measuring the ratio of nitrogen to oxygen in GS 3073. The galaxy contains a nitrogen-to-oxygen ratio of 0.46, far higher than can be explained by any known type of star or stellar explosion.

Devesh Nandal, a Swiss National Science Foundation postdoctoral fellow at the CfA’s Institute for Theory and Computation said, “Chemical abundances act like a cosmic fingerprint, and the pattern in GS 3073 is unlike anything ordinary stars can produce. Its extreme nitrogen matches only one kind of source we know of: primordial stars thousands of times more massive than our Sun. 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.”

The researchers modeled how stars between 1,000 and 10,000 solar masses evolve and what elements they produce. They found a specific mechanism that creates massive amounts of nitrogen:

• These enormous stars burn helium in their cores, producing carbon;
• The carbon leaks into a surrounding shell where hydrogen is burning;
• The carbon combines with hydrogen to create nitrogen through the carbon/nitrogen/oxygen (CNO) cycle;
• Convection currents distribute the nitrogen throughout the star; and,
• Eventually, this nitrogen-rich material is shed into space, enriching the surrounding gas.

The process continues for millions of years during the star's helium-burning phase, creating the nitrogen excess observed in GS 3073.

1000–10,000 M_⊙ Primordial Stars Created the Nitrogen Excess in GS 3073 at z = 5.55
https://iopscience.iop.org/article/10.3847/2041-8213/ae1a63
https://arxiv.org/pdf/2502.04435

Connecting JWST discovered N/O-enhanced galaxies to globular clusters:
evidence from chemical imprints, Xihan Ji et al., 26 November 2025
https://academic.oup.com/mnras/article/545/3/staf2110/8343310


Dating N-loud AGNs at high redshift
GS_3073 as a snapshot of a ω Centauri-like evolution of a nuclear star cluster
F. D’Antona et al, 26 August 2025
https://www.aanda.org/articles/aa/full_html/2025/08/aa54957-25/aa54957-25.html

the chemical properties of this system match those expected at a specific point in the evolution of the abundances in the extreme populations of the former nuclear star cluster ω Centauri (ωCen). This analogy, along with the N/O, C/O, and Fe/O abundances in GS_3073, lead to an estimate of an age range of 270–440 Myr for this object, which is much younger than the redshift (z=5.5) age of ∼1 Gyr.