A recent detection of JWST is the subject of much discussion. Discoverers suggest this could be an incredible record: it could be the oldest galaxy we have ever seen. This remains to be confirmed and other hypotheses are also very intriguing. The object could be an extremely dusty galaxy or a cold object in the Milky Way, such as a brown dwarf or a free-floating planet.
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The object was discovered by JWST as part of the Cosmic Evolution Early Release Science (CEERS) survey and has the official name CEERS ID U-100588. In a paper that has not yet been peer-reviewed, it was nicknamed “Capotauro,” after a mountain on the border between the Italian regions of Tuscany and Emilia-Romagna. If Capotauro is truly the most distant known galaxy, it could radically change our understanding of galaxy evolution.
The general idea of the formative years of the universe suggests that it took several hundred million years for the protogalaxies to come together after the Big Bang. The most distant known galaxy to date is known as MoM-z14; MoM is an acronym for Mirage or Miracle, whose light traveled 280 million years after the Big Bang. If initial estimates are confirmed, Capotauro’s light would only come 90 million years after the beginning of the universe.
Astronomers love to compare the 13.8 billion years of existence of the universe to a single Earth year. This is known as the Cosmic Calendar. This helps us quantify things in a practical way. So, if the Big Bang took place on January 1st at midnight, our galaxy was formed on March 1st, Earth on September 14th and Homo sapiens appeared on December 31 at 11:52 p.m. What about these extreme galaxies?
In the cosmic calendar analogy, each day lasts approximately 40 million years. Some of the oldest galaxies are expected to have formed after the first week of January (MoM-z14 is January 8), while Capotauro appears to have formed in the early hours of January 3.
Obviously this would be exciting, but while the initial data is intriguing, without confirmation that the galaxy is really that far away, it’s important to consider other options. If the object is such a distant galaxy, it must be incredibly bright, and during its short lifetime it must have converted gas into stars with an efficiency not seen since in the entire universe.
An equally bold new explanation for these objects is that they are black hole stars, where the black holes are enveloped in a swirling cocoon of hydrogen that would make the object appear like a distant, compact object.
The study was submitted to Astronomy & Astrophysics and is available on arXiv.
