Sighting in Auxerre, September 17, 2019

At 05:45, when the witness opened their window, they noticed something that struck them as strange: a very bright white point whose intensity seemed at times to dim slightly before brightening again. Two fainter lines extended from this point, one running down and the other up, both toward the right, forming a "V". The witness had the impression of a triangular shape. The phenomenon stayed motionless and made no sound.

The witness stepped away for a few minutes to get ready for work. On returning to the window, the phenomenon was still in the same place. They then took three photos: the first showed a bright point with camera shake, while the other two showed three bright points arranged in a "V". Around 06:50, the witness's mother, who had just got up, also saw the phenomenon. The observation lasted more than an hour, with the phenomenon staying high in the sky and clearly visible until daybreak weakened it and made it vanish. The witness placed it to the east-southeast at 60° elevation; the photos allowed this to be corrected to about 135° azimuth and 18° elevation.

The investigation concluded that the witness had seen Sirius, at magnitude -1.46, very bright at that hour. Over the period concerned, its azimuth moved from 135° to 149.5° and its elevation from 13.5° to 20.2°, which matches the account. Such slow motion is hard to notice with the naked eye over an hour, without any reference point. The changes in brightness came from scintillation, caused by atmospheric turbulence. The "V" most likely came from the photos: camera shake produced it in the last two, and the witness probably described the image rather than what they saw with the naked eye. The testimony was precise and consistent, supported by a sketch, photos of the location and two witnesses, only one of whom gave an account. GEIPAN classified the case as A.