Astronomers accidentally found a galaxy without a single star

A group of astrophysicists from the Green Bank National Radio Astronomy Observatory accidentally discovered something unusual — a spiral galaxy in which not a single star was found.. This may be the first discovery of a primordial galaxy in the Universe — a cloud of gas that has remained unchanged since the beginning of our Universe.

The region of gas moving away from us is indicated in red, and the region of gas moving towards us is indicated in blue. Image source: STScI/NSF/GBO/P.Vosteen

No one deliberately intended to look at that part of the sky where the Green Bank radio telescope was accidentally pointed. It was planned to jointly observe a completely different part of the sky in tandem with the French Nançay radio telescope. Both groups worked on the program for observing low surface brightness galaxies (LSB galaxy, low-surface-brightness galaxy). These are usually dwarf galaxies with rare stars. Such objects are 95% dark matter and there is much more interstellar gas in them than there are visible stars.. Thus, the radio telescope was ready to capture data on interstellar gas at the observed point, but it happened like a shot at random.

The findings stunned scientists. They saw an object, indexed J0613+52, with a size and shape reminiscent of a classic spiral galaxy like our Milky Way or others. However, not a single star was discovered in it. The gas cloud behaved like a galaxy and rotated around its center, as shown by Doppler shift measurements. One area of it was moving towards us, the other was moving away from us.

The object behaved as if all the stars had suddenly disappeared from the Milky Way. It is possible that the gas density in the J0613+52 galaxy was insufficient to trigger star formation processes, and external events triggering this process did not occur. Scientists do not rule out that they simply did not see stars in J0613+52, but they reserve the right to hope that this may be the first discovery in our part of the Universe of a primary galaxy, such as it was 13.8 billion years ago.

Further observation of J0613+52 may be difficult because it is only visible in radio wavelengths. But this also makes us think about searching for similar objects in other parts of the sky using radio telescopes. Scientists have found something potentially surprising and are now eager to find out more about it.