Did a simple render of a new build, nothing clever about the settings but i got a halo around the object, what's that about? not noticed anything like that before.
I do nto seen any "halo" around your aircraft, even when I doubleclick on it and look at the bigger picture that pops up.
...nothing clever about the settings...
Some background information about your settings could be helpful, since this enables me and others to get an insight what kind "(un)clever settings might have produced any? halo? effect (or not) around your object.
So if you can add a screenshot (next time) about your used settings, would be most helpful to get any usable answer to your question.
Is the background a coloured piece of geometry used as a stage or is it just an horizon or world background colour? If there's a stage it could be caused by lighting, maybe diffused light from the plane?
If there is no stage, try lowering the camera clipping to just beyond the subject and see if that helps. Just spit-balling ideas here. I don't know for sure if it'll help but if it's not the lighting I'd assume it's the camera based on the circles being centred. You could probably test this by moving the camera and seeing if the circles move with it.
