This is a planet building gained through a blueprint drop. It would be size 2 with a small amount of cloak (say 100 maybe), but also provides a bonus to the planet where it is constantly detecting scans.

This would appear on the planets page as another column that shows the number of people that have scanned a planet. You would still need to use the advance probe to see the details, and owing to it taking up space, it would be something that you would want to put only on your better planets, but it would allow you to keep a closer eye on them, rather than probing them every few days.

Uh...no. Just cloak them to death. Flux probes are pretty damn common once your arti production gets high enough and a blueprint for this? We'd never be able to take planets again.

Yea, the probes are common enough, but the planet fluxes aren't. It won't stop you being able to take a planet, just stop you spending forever probing all your planets every few days.

I originally thought of it as a building as there is a trade off with its usefulness against the lost space, but another way of doing it (if it is the need to use up flux probes that is the problem) is to have a CTL recepie for an artifact that acts as a trap, displaying the scanned planets for a week.

We already have a trap that tells you when a planet's scanned.