On December 25, 2024, at an international conference on high-energy astrophysics, Konstantin Postnov, director of the Moscow State University’s State Astronomical Institute, announced that scientists will soon have the opportunity to detect hypothetical 'anti-stars' within our galaxy. This development follows the planned launch of two advanced orbital X-ray observatories: the European Athena and the American Lynx.
In 2021, French researchers identified 14 potential candidates for anti-stars in the Milky Way. However, confirming their existence requires new observational instruments due to the unique characteristics of their expected emission spectra. Current telescopes, including Japan's XRISM, would need over 11 days of continuous observation to detect the few necessary photons.
Anti-stars are theorized to consist of antimatter counterparts to regular matter, resembling ordinary stars in structure and behavior, and generating light through similar nuclear reactions involving antimatter particles. Recent findings from the AMS-02 detector aboard the International Space Station have revealed an unexpected abundance of antimatter particles in near-Earth space, prompting interest in anti-stars as a potential source.
Cosmological theories suggest that such objects may have formed in the early universe and could still exist today. Despite this, astronomers have yet to find any anti-stars in the Milky Way or other galaxies.
Russian researchers estimate that anti-stars can be identified by specific lines in their spectral structure, which are linked to the decay of exotic atoms known as protons, composed of a proton and an antiproton. These interactions lead to rapid annihilation, producing multiple photons.
Postnov indicated that the spectral features resulting from these decays would be too subtle for detection by existing optical and X-ray telescopes but could be observed by the upcoming Athena and Lynx missions. Their planned launches in the next decade will provide the first opportunity for scientists to discover anti-stars and investigate their connection to the surplus of antimatter detected in near-Earth space.
Cosmologists theorize that the universe initially contained equal amounts of matter and antimatter. If true, the universe should not exist as we know it, as matter and antimatter would have annihilated each other shortly after the Big Bang. This long-standing puzzle raises questions about why antimatter is virtually absent in the observable universe.
Some scientists speculate that matter and antimatter may differ subtly yet significantly in certain physical properties, potentially explaining the scarcity of antimatter. To explore these anomalies, researchers are studying interactions between antimatter particles and regular matter, as well as various natural forces, using particle accelerators and instruments aboard the ISS.