SAINT-MICHEL-SUR-ORGE (91) 10.08.2015

On Monday 10 August 2015 between 01:00 and 02:00, 2 people observed an intriguing coloured light in the sky. One took photographs. Only 1 account was collected. GEIPAN considers a slowly moving light watched for about 1 hour suggestive of a celestial object. Arcturus was at azimuth 283° and elevation 13°, matching the reported direction towards the N104/A10 junction at azimuth 282° and estimated elevation 15°, fairly near the horizon. The witness saw the phenomenon again on subsequent days, sometimes with fewer colours. Météociel records show unsettled weather with pressure and wind variations on the first night. GEIPAN explains that stars scintillate strongly at low elevations, particularly in disturbed air caused by wind or heat, as that evening. Stars or planets viewed low in the sky through binoculars can often appear to blink slowly in multiple colours. The witness did not mention a star in the field of view, although Arcturus should have been visible in that direction. The photographs add little information because of substantial camera shake and low brightness. GEIPAN classifies the case A: observation of Arcturus.