That's what stinks. This system isn't in the EDDB database so I have no idea where the nearest base is to sell it.
Of course not (well, more or less - the two databases in ED and EDDB/EDSM are independent, I
think EDDB and EDSM are using the same DB nowadays). Since you were the first to discover this system, who should have uploaded it to EDDB? If you want to fix that (for the future) and you're playing on PC (again, I
think there are ways for XBox/PS CMDRs to contribute, I just never looked into them), run one of the helper apps (like EDMC or EDDiscovery) that will automatically upload any data on newly discovered systems into EDDB/EDSM. On the downside, that data is then also immediately available to any other CMDRs, who then (in theory) would be able to snipe that "first discovery" bonus from you.
Otherwise, that system will stay unknown to EDDB unless some other CMDR goes there, scans it and uploads the system data.