[7] A few other galaxies share the primary characteristics of Hoag's Object, including a bright detached ring of stars, but their centers are elongated or barred, and they may exhibit some spiral structure.

[2] In the initial announcement of his discovery, Hoag proposed the hypothesis that the visible ring was a product of gravitational lensing.

Such an event would have happened at least 2–3 billion years ago,[14] and may have resembled the processes that form polar-ring galaxies.

However, there is no sign of any second galaxy that would have acted as the "bullet", and the likely older core of Hoag's Object has a very low velocity relative to the ring, making the typical formation hypothesis implausible.

However, a team of scientists that analyzes the galaxy admits that "if the carnage happened more than 3 billion years ago, there might not be any detritus left to see.