I was analyzing the Hubble Ultra Deep field image and I realized that if you look at the image from a certain distance from your monitor, you can notice there is a ring of galaxies, forming a circle. The following are the HUDF image and an image where I try to show where I see the circle (it is not properly placed, as the red line crosses some galaxies that are part of the circle, but you can get the idea). My question is: Can this have any meaning at all? What's the explanation for this? Can it possibly have something to do with the expansion of the universe or the Big Bang? (probably not, but anyway, I want to ask.) Cheers.