VILLENEUVE-D'ASCQ (59) 26.11.2021

During the night of 26–27 November 2021, between 23:00 and 00:30 in Villeneuve-d'Ascq (59), a witness made 2 observations of about 15 minutes each of something initially resembling an extremely bright star. It sometimes appeared blue and made almost continuous slight movements, mostly in straight lines, while remaining in the same area. During the second observation it was still present but had moved what the witness described as about 3–4 m upwards and to the right. Its estimated elevation was 15°–30°, with an estimated initial azimuth of 140° and final azimuth of 160°. No other account was collected. GEIPAN considers the very long observation period indicative of an astronomical object. It identifies the object as the star Rigel using the site cited as JPL/NASA Horizons System, NAO. The source gives these parameters: - At 23:00: azimuth 137°, elevation 22°; at 23:30: azimuth 160°, elevation 29°. - Rigel's magnitude over this period was 0.2, making it readily visible and consistent with the witness's description of extreme brightness. - Rigel is a very hot star that appears blue, also matching the account. The witness found its extreme brightness, apparent immunity to the wind, prolonged presence in the same area and almost continuous slight straight-line movements strange. GEIPAN explains that the first features match the bright star Rigel, which moved about 20° during the observation period and therefore appeared to move very slowly. It attributes the small movements to the autokinetic effect, or autokinesis: a common perceptual illusion when looking at a point of light in darkness. The source refers to an article on this effect and to GEIPAN's website, but the latter reference is incomplete. GEIPAN classifies the case A: observation of the star Rigel.