Probably just a nub question...

If I toss a "Planet flux" on a planet, it is then hidden from ALL future scan lists? BUT, its location still could be hacked? Also, does that mean its hidden for good? And...if someone "found" it before I colonized it, does that make it "disappear" from said person's list? I just want to make sure the artifact does what I think it does before I use it...

Planet fluxes only get rid of current scans, not future, yes it can still be hacked from you, yes it says it disappeared.