St. Elmo's fire

Luminous plasma created in an electric field

St. Elmo's fire (also called corposant, Hermes fire, furole, witchfire or witch's fire) is a weather phenomenon in which luminous plasma is created by a corona discharge from a rod-like object such as a mast, spire, chimney, or animal horn in an atmospheric electric field. It has also been observed on the leading edges and windshields of aircraft by pilots.

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