Wouldn’t we need asteroids of total mass comparable to the anti-star? Where would you we enough? Any planets or asteroid belts around that star would be antimatter too, almost certainly.
Yes, you would need that much matter to be annihilated. But finding one system’s worth of mass is a (relatively) trivial part of the problem. It is a whole order of plausibility easier than trying to throw an antimatter star into a black hole. Taking apart the nearby systems and throwing the planets and asteriods at the offending star is just an engineering problem once you have that sort of tech. I could probably do it myself if you gave me 30,000 years to work out the finer details. You either push on the asteroid while standing on something bigger or you launch tiny things off the asteroid at large fractions of the speed of light in a suitable direction.
Throwing a whole antimatter star into a suitable black hole? I can’t even do that one in principle (within 2 minutes of thought). Apart from being really big and too hot to put propulsion devices on… it’s made out of F@#% antimatter. The obvious options for accelerating it are gravity and photons, neither of which care about the ‘matter/antimatter’ distinction. If you have enough gravity hanging about in the vicinity then the star is probably already falling into the black hole. And if you are planning on pushing a star about using only photons.… well, you may end up using more than just one star worth of matter to pull that off.
Then there is the problem of finding a suitably large black hole to throw it at. They tend to have stuff in their orbit (often the rest of the galaxy). Navigating an antimatter star to the black hole without it annihilating itself of the way there would be tricky. It isn’t easy to steer these things.
What may be easier is to dedicate a year or two run time on a Jupiter Brain to work out just the right size rock to throw at just the right time at just the right place. The resulting explosion would be chosen to knock the star in the right direction, or in the right pieces in the right directions, or whatever it is that antimatter stars do when you throw rocks at them. Then most of the destruction would be from it hitting the other stars that you aimed for. You would dispose of the weapon by triggering it in a controlled manner.
Yes, you would need that much matter to be annihilated. But finding one system’s worth of mass is a (relatively) trivial part of the problem. It is a whole order of plausibility easier than trying to throw an antimatter star into a black hole. Taking apart the nearby systems and throwing the planets and asteriods at the offending star is just an engineering problem once you have that sort of tech. I could probably do it myself if you gave me 30,000 years to work out the finer details. You either push on the asteroid while standing on something bigger or you launch tiny things off the asteroid at large fractions of the speed of light in a suitable direction.
Throwing a whole antimatter star into a suitable black hole? I can’t even do that one in principle (within 2 minutes of thought). Apart from being really big and too hot to put propulsion devices on… it’s made out of F@#% antimatter. The obvious options for accelerating it are gravity and photons, neither of which care about the ‘matter/antimatter’ distinction. If you have enough gravity hanging about in the vicinity then the star is probably already falling into the black hole. And if you are planning on pushing a star about using only photons.… well, you may end up using more than just one star worth of matter to pull that off.
Then there is the problem of finding a suitably large black hole to throw it at. They tend to have stuff in their orbit (often the rest of the galaxy). Navigating an antimatter star to the black hole without it annihilating itself of the way there would be tricky. It isn’t easy to steer these things.
What may be easier is to dedicate a year or two run time on a Jupiter Brain to work out just the right size rock to throw at just the right time at just the right place. The resulting explosion would be chosen to knock the star in the right direction, or in the right pieces in the right directions, or whatever it is that antimatter stars do when you throw rocks at them. Then most of the destruction would be from it hitting the other stars that you aimed for. You would dispose of the weapon by triggering it in a controlled manner.