Schematic view of the observer-galaxy system. The LMC center O(α₀, δ₀, D₀) is chosen to be the origin O of the (x, y, z) coordinate system. Top: projected view of the sky. All vectors and angles lie in the plane of the paper. The angles ρ and ϕ define the projected position on the sky of a given point with coordinates (α, δ). Bottom: side view of the observer-galaxy system. The distance from the observer to the LMC center is D₀ and the distance from the observer to an object is D. The component v₁ lies along the line-of-sight and points away from the observer.