Hubble Discovers a Galaxy That Never Was: A Unique Cloud of Dark Matter.

According to ТСН: Astronomers collaborating with NASA's Hubble Space Telescope made an astonishing discovery in the universe – a starless gas cloud containing a large amount of dark matter. This object has been unofficially named “Cloud-9” and is believed to be a remnant from the early stage of galaxy formation, a kind of “galaxy that never was.”

This is the first historical confirmation of the existence of such an object, which could significantly change researchers' understanding of galaxy creation, the development of the early universe, and the nature of dark matter.

“This is the story of a galaxy that never happened. In science, we often learn more from failures than from successes. The absence of stars here confirms the theory and indicates that we have found the primordial building block of a galaxy that never formed,” explained the research leader Alejandro Benitez-Llambay.

The research results were published in The Astrophysical Journal Letters and presented at the 247th meeting of the American Astronomical Society in Phoenix.

Astrophysicist Andrew Fox from the Space Telescope Science Institute (STScI) noted that Cloud-9 opens unique opportunities for studying dark matter.

“We know from theory that most of the universe's mass consists of dark matter, but it is incredibly hard to observe because it does not emit light. Cloud-9 provides a rare opportunity to see an object dominated by dark matter,” added Fox.

Cloud-9 belongs to the class of RELHIC (reionization-limited HI clouds), meaning it is a cloud of neutral hydrogen formed in the early stages of the universe's existence but failed to give birth to stars. Although such objects had been theoretically predicted for decades, observations of them remained at the level of theory.

Thanks to the Hubble telescope, scientists were able to confirm with certainty that Cloud-9 does indeed have no stars.

“Now we can say for sure: there is really nothing there,” explained lead author of the study Gagandeep Anand.

Researchers believe that Cloud-9 may be just one of many similar objects near our galaxy. Astronomer Rachel Beaton emphasized that among galactic neighbors, there may be many “abandoned houses.”

Astronomical Characteristics of Cloud-9

The core of Cloud-9 consists of neutral hydrogen and has a diameter of about 4,900 light-years. The gas mass in this cloud is approximately one million times more than the mass of the Sun, while the mass of dark matter is estimated to be five billion solar masses.

Unlike other hydrogen clouds near the Milky Way, Cloud-9 is compact and has a nearly spherical shape, making it unique.

Scientists believe that the discovery of such “galaxies that never were” could help fill gaps in understanding the structure of the universe. Researching gas and dark matter, as well as avoiding a focus on bright stars, reveals hidden aspects of cosmic evolution.

Identifying such objects as Cloud-9 may prove a challenging task, as they can easily blend in among brighter galaxies and be vulnerable to influences from the intergalactic medium. However, Cloud-9 has become the first convincing evidence of structures that never became galaxies.