A triangle shape in Yvelines, France

On January 2, 2012, a witness observed from 4:30 PM a triangular object, fitted with flashing red and yellow lights. The object seemed to rotate on itself at times and remained stationary. The witness alerted the air navigation service at Chavenay, which also observed the phenomenon. The observation lasted three hours. No other testimony was collected. GEIPAN called this service at Chavenay; the correspondent said he had indeed seen a very bright luminous point. After a quick analysis, this observation could be only the planet Venus, and not be the object reported by the witness. Also noted that evening was the planet Jupiter near the Moon (see attached star chart). Since Venus is fairly low on the horizon, scintillation makes its colors vary a lot. The witness, recontacted, specified that he had indeed identified Venus, that this luminous object was close to the direction of Venus, but fixed for 2 hours, without however indicating precisely its direction or its apparent height on the horizon. The observation direction corresponds to the Château de Plaisir (Les Saussaies): a tethered luminous balloon could have given the same visual impression. GEIPAN could not verify this hypothesis. Given the imprecision of the testimony concerning the observation direction, and the low strangeness of the case (object fixed for 2 hours), the absence of photos despite the length of the observation, the absence of other testimonies, GEIPAN classifies this case "C" for lack of information.