For anyone looking for where this mission is "System T562 - Tau Patrol". I finally found it in Eridan Belt.
I couldn't find any information on this mission anywhere ie forums, google, and wiki.
I spent a couple of days looking for this mission traveling throughout the map.
I hope this makes someone else's life a little easier.
That mission is one of the randomly generated exploration sector missions. There are several tens of thousands of them, and aside from the basic archetypes they're based on no complete attempt to catalog them has ever lasted long enough to be useful.
You get them by entering the random systems that appear in exploration sectors. If you leave and don't abandon the mission, you can return to it by going to the sector you got it in, where it'll appear in your alerts area.