Antimatter, Not Just for Star Trek #astronomy #universe #cosmology

It seems reasonable that no significant amounts of antimatter exist in the universe. When matter and antimatter collide, they annihilate in a blast of energy. You don’t need a physics class to know that – Scottie on Star Trek told us so.

Save us, Scottie

But what if there are antimatter stars? Antistars would shine like a regular stars, but if the star’s gravity pulled in regular matter, the interaction would release a high-energy flash of light in a specific color of gamma rays. Has anyone seen clues to such a phenomenon?

In 2018, the Alpha Magnetic Spectrometer 2 (AMS-02) experiment on the International Space Station possibly detected several antihelium nuclei, suggesting that some original antimatter survived to form antistars and even antigalaxies. physics.apps.org

Where would antihelium come from? From the Big Bang? If a few atoms survived to wander into our instruments, there might be more. So what about gamma rays? Antimatter annihilation is only one source of such emissions, but the search began for just the right combination of frequencies and flashes. It’s a new hypothesis, so more data is needed, but there might be two antistars per million normal stars based on the Fermi Large Area Telescope.

I sure don’t want to visit such a star because I (or more realistically, my probe) would go poof. But it would be fun to know more.