diffraction spike

A diffraction spike is a starburst pattern of light rays that appears around bright objects in images taken through telescopes, caused by light bending as it passes through the telescope's structure. These distinctive cross-shaped or X-shaped spikes occur because light waves interact with the thin supports that hold the telescope's mirrors in place, creating a phenomenon similar to how light bends around any obstacle. You've likely seen famous examples in images from the James Webb Space Telescope, where brilliant stars are surrounded by these striking geometric patterns that actually help astronomers identify and study the brightest objects in space.