A team of astrophysicists, led by Mireia Montes from the Instituto de Astrofísica de Canarias (IAC), has identified the largest and most diffuse galaxy on record, named “Nube.” Discovered using data from the Gran Telescopio Canarias (GTC) and the Green Bank Radiotelescope (GBT), Nube is an almost invisible dwarf galaxy with a surface brightness so faint that it went unnoticed in previous sky surveys.
Nube’s name, meaning “Cloud” in Spanish, was suggested by the 5-year-old daughter of one of the researchers due to its diffuse appearance. The galaxy’s stars are spread out over a large volume, making it nearly undetectable in previous observations.
This newly discovered galaxy possesses unique characteristics, being ten times fainter than other dwarf galaxies while also being ten times more extended. Although it is one-third the size of the Milky Way, Nube has a mass similar to the Small Magellanic Cloud.
The researchers estimate Nube’s lifetime to be at least 40 minutes, which is ten million times longer than previously demonstrated for similar objects. The galaxy’s period can be varied over a wide range by changing experimental conditions. The researchers also note that Nube may enter areas where it loses its periodicity, exhibiting chaotic behavior.
The discovery challenges existing models of dark matter, as the density of stars in Nube remains relatively constant throughout the object, defying the typical distribution found in galaxies. Cosmological simulations struggle to reproduce Nube’s extreme characteristics within the cold dark matter model.
The researchers are exploring the possibility that Nube’s unusual properties could indicate extremely small-mass particles making up dark matter. If confirmed, this hypothesis would provide insights into the quantum physics properties on a galactic scale, offering a unique demonstration of nature’s unity across different scales.
This groundbreaking discovery opens new avenues for understanding the universe, and further observations and analyses will contribute to unraveling the mysteries surrounding Nube and similar celestial objects.