Thanks for the info.
The Events page doesn't seem to list the actual system body, it just says it's a population without going into further detail. "14th November 2053 00:46:36,Kapteyns Star,Population Detected! Thermal Signature 10 Race ID: Kapteyns Star Aliens #166."
However, a check of the System View did finally show me that it's an outpost emplaced on an asteroid. I had previously lost contact with another outpost, which was only strength 5. So Either there are two outposts in the system, or the precursors are building new deep space tracking stations.
Anyhow, I'm 98% sure that when I was checking the system view earlier, before I brought in my scout to do a search for this guy, the asteroid in question was marked as empty. Do you have to be able to see populations for the System View to show them?
I'd love to know what's up here.