Purpelia wrote:
All it takes to investigate an obviously suspicious system is for a FTL capable ship to take a look at your odd system on a map and chart a strait line through it and its own homeworld and than take off in the opposite direction stopping once every light year to take a sensor reading using regular non FTL sensors. Eventually it is going to reach a distance where the image it gets is from before you did your magic.
Or you could just use your FTL technology to send astronomical data to the past.