An optical illusion case in Toulouse

Summary

On December 14, 2015, a witness and his wife observed through fog a bright point in the sky that seemed to sway and slightly grow. The GEIPAN classified this case as "B", indicating a probable explanation. According to astronomical data, Venus was in the direction reported by the witness, very bright at 22° elevation, though the witness estimated 60°. Arcturus was also present but less bright. The perception of movement of the light was explained by an optical illusion known as autokinetic effect, common when observing bright objects through fog. This case involved only one witness and no physical evidence, reinforcing the GEIPAN's conclusion.