This is a NASA Hubble Space Telescope image of what is thought to be an unusual collision between two asteroids. But consistent with the photos in this document, the partial torus suggests it may be a powered craft. We may be able to see part of the ring because a toroidal field has captured debris that is in front of the supposed craft. Perhaps only part of the ring is visible to us because the material is not evenly distributed.
Theoretical research at the University of Sydney, summarized in an article on the Alcubierre warp drive, supports the proposal that the object is a powered craft. It was observed that "space is not just an empty void between point A and point B; rather, it's full of particles that have mass (as well as some that do not.) What the research team ... has found is that these particles can get 'swept up' into the warp bubble and focused into regions before and behind the ship, as well as within the warp bubble itself." The following enhanced image is consistent with this prediction.
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