NASA's James Webb Space Telescope has uncovered a galaxy that existed just 1 billion years after the Big Bang, that's breaking all the rules.
This celestial oddball is lighting up the early Universe in ways never seen before, and could represent a key stage in galactic evolution between the very first galaxies and those we see today.
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Gassy glamour of GS-NDG-9422
GS-NDG-9422, or '9422' for short, is a galaxy not content with letting its stars steal the spotlight.
The gas in galaxy 9422 is outshining its stellar population, giving astronomers a new piece of the puzzle when it comes to understanding early galactic evolution.
Dr. Alex Cameron of the University of Oxford, who led a study into 9422 using the Webb Telescope, says he was surprised when he first saw the galaxy's spectrum.
"My first thought was, 'that's weird,'" he says.
"Which is exactly what the Webb telescope was designed to reveal: totally new phenomena in the early Universe that will help us understand how the cosmic story began."
Superstars
What's causing the galactic light show in galaxy 9422?
The culprit appears to be a population of stars hotter than anything we see in our cosmic neighbourhood.
While the hottest stars in our local Universe typically reach temperatures between 70,000 to 90,000°F (40,000 to 50,000°C), galaxy 9422 has stars hotter than 140,000°F (80,000°C).
And these cosmic furnaces are pumping out so much energy, they're causing the surrounding gas to glow brighter than the stars themselves.
A missing link in galactic evolution
The study of galaxy 9422 could represent a crucial piece in the puzzle of how the early Universe evolved.
Cameron reached out to Dr. Harley Katz of the University of Oxford and University of Chicago, to help decipher exactly what's going on.
They found that computer models of cosmic gas clouds heated by hot, massive stars, so much that their gas outshone the stars themselves, nearly perfectly matched Webb’s observations.
"It looks like these stars must be much hotter and more massive than what we see in the local Universe, which makes sense because the early universe was a very different environment," says Katz.
Gas outshining stars is something predicted in the environments of the Universe’s first generation of stars, known as Population III stars.
"We know this galaxy does not have Population III stars, because Webb data shows too much chemical complexity," says Katz.
"However, its stars are different than what we are familiar with – the exotic stars in this galaxy could be a guide for understanding how galaxies transitioned from primordial stars to the types of galaxies we already know."
What's next?
This discovery seems to have raised more questions than answers, which is often the sign of a key breakthrough.
Is galaxy 9422 a cosmic oddball, or are there more galaxies like it waiting to be found? What can it tell us about even earlier stages of galactic evolution?
One thing's for sure: the study is just getting started.
As Cameron puts it: "It’s a very exciting time, to be able to use the Webb telescope to explore this time in the universe that was once inaccessible."
"We are just at the beginning of new discoveries and understanding."
Read the full paper, published in the Monthly Notices of the Royal Astronomical Society, at academic.oup.com/mnras/article/534/1/523/7697173
