Wow, that's definitely strange! Never seen that before! I've seen a rainbow go right round the sun once but never a dirty great brown circle... Look
forward to seeing the explanation for this. Nice one for posting it!
It probably is the same thing, but on that wiki page it says that the inner circle is red and the outer circle is bluish. From the video posted I see
inner brown and outer yellow, not sure that makes any difference though.
I've see this happen with the moon quite a few times, but never the sun.
And I've also seen a rainbow around the moon. That was one of the best things I've seen in my life.