Capotauro

CEERS U-100588 (named provisionally as "Capotauro") is an astronomical object detected by the James Webb Space Telescope (JWST) on the Cosmic Evolution Early Release Science (CEERS) Survey,^[1] which could be an extremely distant Lyman-break galaxy with a photometric redshift (z) of 32, a dusty interloper galaxy with a redshift (z) of 6, a rogue planet or a Y2–Y3 spectral type brown dwarf.^[2]

CEERS U-100588

Magnified image of CEERS U-100588 (Capotauro) as observed by the JWST. Credit: G. Capriotti, G. Gandolfi et al.
Other designations	Capotauro
Observation data (Epoch J2000)
Constellation	Boötes
Right ascension	14h 19m 32.97s
Declination	+52° 47′ 52.11″
Redshift	~6 (dusty interloper galaxy hypothesis) ~32 (Lyman-break galaxy hypothesis)

It is characterized by a significant absence of light in certain wavelengths and a pronounced drop in others. Its paucity of light and spectral peculiarities make it an enigmatic object, defying conventional classifications and sparking debate about whether the standard cosmological model might need adjustments,^[2] although another study suggests otherwise for galaxies up to redshift z=30.^[3]

The research team at the University of Padua named the mystery object after a mountain in Italy : Capotauro is the ancient name of the peak now known as Corno alle Scale, located in the Apennine Mountains.^[2][4] Lead researcher Giovanni Gandolfi said: "Capotauro could be the farthest galaxy ever seen at a timescale that is compatible with the first stars and black holes to form in the universe". It has been compared to the hypothesised ' black hole star', which is a primordial black hole surrounded by a dense atmosphere. Other scientists have been sceptical about whether Capotauro is a galaxy however.^[4]

If Capotauro is spectroscopically confirmed to be at redshift z=32, then it would have existed just 90 million years after the big bang.^[5] This is nearly 200 million years before the current record holder MoM-z14 and would place Capotauro closer to the very beginning of time than any structure we have yet seen. A galaxy appearing only 90 million years after the big bang implies that current theories about how quickly structures had formed are at odds with these observations by Gandolfi and his team. However, there could be other explanations as well and the initial theory that Capotauro might be at such an extreme redshift is doubted.^[5]

Capotauro appears to be very bright for a young galaxy.^[6] The object's apparent luminosity implies a mass near a billion suns which is difficult to reconcile with current theories. Nicha Leethochawalit from the National Astronomical Research Institute of Thailand said "To achieve such a mass, the efficiency at which the galaxy turned gas into stars would have to be close to 100 percent", whereas an efficiency of 10-20% is thought to be more usual. Possibilities include: a black hole star, a brown dwarf, an ultra-young galaxy, a nearer dusty galaxy (or interloper) and a rogue or hostless planet.^[6]

An analogy that can be used, often called the 'Cosmic Calender', is that of comparing the length of the universe's existence (near 13.8 billion years) to that of a year on earth, which works out as about 40 million years a day.^[7][8]. If the big bang was at midnight on the 1st of January, then the Milky Way was formed on the 1st of March, Earth on the 14th of September and humans appeared on the 31st of December at 11:52 pm. Continuing the analogy, the most distant object MoM-z14 would form on the 8th of January, whereas Capotauro has been estimated to have formed on the 3rd of January.^[7]

See also

• List of the most distant astronomical objects