Stars made of antimatter could exist in the Milky Way

[Judi Lynn]

By Adam Mann - Live Science Contributor 1 day ago

Astronomers try to solve the mystery of antihelium by searching for antistars.



The Alpha Magnetic Spectrometer in orbit. The AMS was used to search for antimatter.
(Image credit: NASA)


Out of an estimated 100 billion stars in our galaxy, no more than 14 may be made from antimatter. That's the result from a new study that scoured the Milky Way for signs of antistars — which are identical to regular stars save for the fact that they would burn antimatter at their cores.

Though the findings turned up mostly empty this time, researchers haven't yet fully ruled out the existence of antistars, whose presence would change much about our understanding of the universe.

The recent search for antistars can be traced back to 2018, when a $1.5-billion experiment called the Alpha Magnetic Spectrometer (AMS) that's attached to the International Space Station captured a few examples of what might be antimatter.

Antimatter is exactly like regular matter but its charge is reversed, so the antimatter equivalent of positively charged protons are negatively charged antiprotons. In this case, AMS detected what looked like antihelium, which has a nucleus composed of two antiprotons and two antineutrons.

More:
https://www.livescience.com/potential-antistars-in-milky-way.html

[qazplm135]

1. If the star is antimatter

wouldn't the planets and asteroids and whatnot around it also be antimatter? It all started in the same spinning disk after all.

And wouldn't that mean passing through dust, rock, particles would likely be matter? I would think we'd have some pretty big explosions happening when that matter collided with the dust and whatnot in the antimatter system. Even an antimatter micrometeorite would be a big bang.

[cstanleytech]

2. Some theories are that antimatter and matter repel each other if I recall and if that is the case

impacts between the two might be rare especially now as the universe has kept on expanding.

[qazplm135]

3. you got a link for that

because I have never seen anything to suggest that's the case.

You'd expect to see antimatter particles move in a gravitational field either towards or away from the source of gravity, and if antimatter is repelled by matter, and given the Earth's gravitational pull, they'd float if not fly up and away and I don't think we see that. Or you'd have a hard time getting matter and antimatter to collide and I don't think we see that either.

And we know photons are their own antiparticles and they are attracted by gravity.

At the end of the day, antimatter is still matter, just with protons and electrons being charged oppositely. It should affect how they interact with gravity which doesn't care about charge (or lack thereof) generally speaking.

[cstanleytech]

4. Not directly but I think it was posted here maybe a year or two ago.

There is this though https://en.wikipedia.org/wiki/Gravitational_interaction_of_antimatter

[qazplm135]

5. which says

there's no real evidence that antimatter acts any differently than matter towards gravity.

We KNOW that they collide, we've done it in labs. There's just no reason I can think of for antimatter to be affected differently by gravity than matter.

Gravity is the weakest of the forces, but it's also the one that seems to act on, well, everything, mass, no mass, regardless of charge positive or negative, and long or short distances.

[cstanleytech]

6. Still that is in the lab the question that unanswered is how much still exists and how does it

behave around ordinary matter outside of a lab.

[qazplm135]

7. Why would it act differently

Outside of the lab??