Astronomers utilizing the James Webb Space Telescope have discovered a peculiar galaxy that dates back just a billion years after the Big Bang. Its unique characteristics are aiding scientists in understanding the formation of early galaxies and moving towards one of the key quests in astronomy: uncovering the universe’s earliest stars.
The team employed Webb’s advanced instruments to analyze the light emitted by the GS-NDG-9422 galaxy across various wavelengths, revealing some intriguing results.
Lead researcher Alex Cameron from the University of Oxford remarked, “When I first examined the galaxy’s spectrum, my immediate reaction was ‘that’s unusual,’ which is precisely what the Webb telescope was developed to detect: entirely new phenomena from the early universe that will enhance our understanding of how the cosmic narrative began.”
The observations indicated that the galaxy’s gas was emitting light more intensely than its stars. This phenomenon is likely due to the stars being extraordinarily hot, which in turn heats the surrounding gas. While typically, large, hot stars reach temperatures between 40,000 to 50,000 degrees Celsius, the stars present in this galaxy were estimated to exceed 80,000 degrees Celsius.
This finding is already compelling, but its significance is amplified as it may offer insight into a class of ancient stars theorized to exist, referred to as Population III stars. Astronomers categorize star populations in reverse order: the stars that are currently forming are known as Population I, while older stars fall under Population II. Population III stars are presumed to be from the universe’s earliest epochs, yet direct evidence for their existence remains elusive.
It is believed that Population III stars would contain almost no heavy elements, as these elements were formed by supernova explosions long after the Big Bang. Therefore, their characteristics would diverge significantly from those of contemporary stars.
Harley Katz, another researcher, stated, “While we know this galaxy does not harbor Population III stars—due to its chemically complex data from Webb—its stars exhibit traits distinct from what we usually encounter. These exotic stars could serve as an important reference in comprehending the transition from primordial stars to the galaxies we recognize today.”
The team is now focused on discovering more of these unusual galaxies to expand their knowledge of how star formation occurred during the first billion years post-Big Bang.
Cameron expressed enthusiasm about the current period in astronomical research, noting, “It’s an exhilarating time to use the Webb telescope to investigate a previously unreachable era in the universe. We are just beginning a wave of new discoveries and insights.”
The findings of this research have been documented in the journal Monthly Notices of the Royal Astronomical Society.
