An account in Cher, France

On March 3, 2013 at around 11:00 PM, a motorist spotted in the sky a sort of white cross among the stars, then noticed, a bit further on, the movements of a luminous phenomenon of color in the sky. His observation would last an hour and a half. The gendarmes called to the scene observed and filmed the oscillations of the phenomenon. The testimonies and the video describe a luminous point that is generally fixed, but changing color and oscillating slightly and randomly. The star Sirius (magnitude -1.44) is in the witness's direction of observation (at azimuth 225°, for about 212° recorded by the gendarmes), only 15° above the theoretical horizon. The weather conditions (see the Meteociel record) can favor extreme scintillation: the atmospheric pressure, falling and continuing the next day, is an indicator of strong winds at altitude, which cause strong scintillation. Star scintillation. The low temperature can cause particular atmospheric optical phenomena if there are ice crystals in the air: halos, crosses. The autokinetic illusion (see autokinetic illusion) could also have played a role. The GEIPAN classifies this case "A": observation of the star Sirius with strong scintillation due to particular weather conditions.