The AI network on board the starship the Chandrasurya was having a nightmare - as AI's go. It had concluded recently - about three or four years back - that the increasing number of micrometeorite impacts on its hull were not accidental at all. Micrometeorites do not in general leave an ionic trail behind them. It had used as much of the micrometeorite defense as was feasible; had upgraded its security environment to careful; but had not yet decided it was now critical. The hull was losing a microscopic amount of integrity, but the Chandrasurya had only reached the heliopause of Alpha Centauri. It predicted that on the grounds of the increasing number of impacts, it would soon reach a maximum level of impacts when it had decelerated to orbital speeds and had reached the Lagagrange 1 point between the two stars. At that stage hull integrity would be seriously, even fatally, compromised.
When you can accelerate a pack of micrometeorites to a high-enough speed, you don't need to be particularly precise in your aiming; when you're aiming at something travelling at an appreciable fraction of the speed of light, you don't need a vast amount of mass. And the aim is to degrade hull integrity, as a starship breaking up from braking stress at speed is such a pretty sight!