I'm surprised nobody answered that on WB.SE, but:

Wouldn't a big Dyson's Sphere do the job?

I remember reading about a Dyson's Sphere large enough to collect all the energy from a solar system, on another thread. This would effectively block all outside interferences.

But this solution depends on what you want in your story.

(If anyone is knowledgeable on the topic, feel free to correct me, I only know the general principle)

I'm surprised nobody answered that on WB.SE, but:

Wouldn't a big Dyson's Sphere do the job?

I remember reading about a Dyson's Sphere large enough to collect all the energy from a solar system, on another thread. This would effectively block all outside interferences.

But this solution depends on what you want in your story. (If you don't want to go hard sci-fi, it will be hard to feature it).

(If anyone is knowledgeable on the topic, feel free to correct me, I only know the general principle)