May 1, 2021 02:10 AM
https://www.sciencealert.com/these-14-mi...antimatter
EXCERPTS: . . . 14 objects could be hiding a big secret. [...] stars made of antimatter - hypothetical objects known as antistars. This would be absolutely huge if true - it could help resolve one of the biggest mysteries in the Universe, that of all the missing antimatter. But there are still a few other things those 14 objects could be.
Every particle of matter that makes up the stuff we see around us - like electrons and quarks - has a counterpart with identical features, except for one thing: an opposite charge. It's thought that particles and antiparticles were produced in equal quantities at the beginning of the Universe.
When a particle and its antiparticle collide, they annihilate each other [...] which suggests that they should still exist in equal quantities (or nothing exists at all, a cheery thought), but for some reason, only trace amounts of antimatter have been detected. We've sort-of grown accustomed to the idea that pretty much none of the 'original' antimatter remains in the Universe. Physicists have developed models and explanations based on that assumption, it's a whole big thing.
Then along came the Alpha Magnetic Spectrometer experiment (AMS-02) aboard the International Space Station. A few years ago, it made tentative detections of antihelium - a discovery that, if validated, means enough fundamental antiparticles could have stuck around to clump into whole atoms of antimatter.
But where? According to a team of astronomers led by Simon Dupourqué at the Institut de Recherche en Astrophysique et Planétologie in France, maybe it's hiding in the form of antistars in the Milky Way.
Because antistars would behave pretty much like normal stars, they would be pretty hard to detect - unless normal matter, such as interstellar dust, accreted onto the star's surface, where it would be annihilated by the antimatter of the star. In turn, this would produce a gamma ray excess at specific energies that, theoretically, we could detect.
[...] It's not hugely likely that these 14 objects are antistars; they could easily turn out to be known gamma-ray emitters such as pulsars or black holes. But they give us a starting point for estimating the number of antistars that could be hiding in the Milky Way... (MORE - details)
EXCERPTS: . . . 14 objects could be hiding a big secret. [...] stars made of antimatter - hypothetical objects known as antistars. This would be absolutely huge if true - it could help resolve one of the biggest mysteries in the Universe, that of all the missing antimatter. But there are still a few other things those 14 objects could be.
Every particle of matter that makes up the stuff we see around us - like electrons and quarks - has a counterpart with identical features, except for one thing: an opposite charge. It's thought that particles and antiparticles were produced in equal quantities at the beginning of the Universe.
When a particle and its antiparticle collide, they annihilate each other [...] which suggests that they should still exist in equal quantities (or nothing exists at all, a cheery thought), but for some reason, only trace amounts of antimatter have been detected. We've sort-of grown accustomed to the idea that pretty much none of the 'original' antimatter remains in the Universe. Physicists have developed models and explanations based on that assumption, it's a whole big thing.
Then along came the Alpha Magnetic Spectrometer experiment (AMS-02) aboard the International Space Station. A few years ago, it made tentative detections of antihelium - a discovery that, if validated, means enough fundamental antiparticles could have stuck around to clump into whole atoms of antimatter.
But where? According to a team of astronomers led by Simon Dupourqué at the Institut de Recherche en Astrophysique et Planétologie in France, maybe it's hiding in the form of antistars in the Milky Way.
Because antistars would behave pretty much like normal stars, they would be pretty hard to detect - unless normal matter, such as interstellar dust, accreted onto the star's surface, where it would be annihilated by the antimatter of the star. In turn, this would produce a gamma ray excess at specific energies that, theoretically, we could detect.
[...] It's not hugely likely that these 14 objects are antistars; they could easily turn out to be known gamma-ray emitters such as pulsars or black holes. But they give us a starting point for estimating the number of antistars that could be hiding in the Milky Way... (MORE - details)
