Antimatter stars may be lurking in the Milky Way galaxy. Scientists came to this conclusion in a study published in Physical Review D.
Antimatter – matter, consisting of antiparticles – “mirror reflections” of a number of elementary particles that have the same spin and mass, but differ from each other in signs of all other characteristics of interaction: electric and color charge, baryon and lepton quantum numbers.
Antimatter is real. In simple terms, it is the same as ordinary (or baryonic) matter, except that it has the opposite charge. This means that when particles of matter and antimatter meet, the two particles annihilate with each other in a burst of energy.
According to the models of the universe, matter and antimatter should have been created in equal amounts during the Big Bang, but today matter seems to dominate the cosmos. Antimatter on Earth can be found rarely and in negligible quantities.
So where did all the antimatter go? It seems that it is almost completely erased due to contact with ordinary matter – people are just lucky that there is excess matter, otherwise the universe as we know it would not exist.
But perhaps the ratio of antimatter to matter is not as distorted as we thought. Theoretically, there is no reason why antimatter cannot form stars and galaxies, planets and even life, if there is no ordinary matter nearby that can destroy it. This is an intriguing possibility, but extremely difficult to confirm – after all, anti-stars will shine just like normal stars.
However, they can prove themselves in other ways. It is quite difficult for anti-stars to appear in a region of space completely devoid of regular matter. Therefore, scientists can potentially detect these “impostors” by the bursts of gamma rays emitted as a result of the annihilation of wandering particles of matter at a short distance.
They were the ones that astronomers were hunting for in the new study. A team from the Research Institute for Astrophysics and Planetology in France analyzed data from the Fermi gamma-ray telescope over 10 years. They studied 5,787 gamma-ray sources in search of anti-stars. However, many other objects also emit gamma rays. Therefore, the researchers focused on those flares that emanate from a single point. In addition, the scientists investigated a spectrum of light similar to that expected from the annihilation of matter and antimatter.
Among these thousands of gamma-ray sources, astronomers have found 14 objects that meet all the requirements. This does not mean that they are anti-stars. The team admits that it could be pulsars or black holes. But there is a possibility that scientists have found traces of anti-stars.
Astronomers have extrapolated the data to predict how many anti-stars there might be in the Milky Way. If such objects are distributed like ordinary stars, and if they have no differences other than charge, then there is one antistar for every 300,000 stars.
This is an intriguing idea and will require further study to find additional evidence.