Astronomy Picture of the Day

Explanation: What's hovering above the Sun? A solar prominence. A prominence is a crest of hot gas expelled from the Sun's surface that is held aloft by the Sun's magnetic field. Prominences can last for days, can suddenly explode into space, or just fall back to the Sun. What decides a prominence's fate is how the Sun's complex magnetic field changes -- the field's direction can act like an offramp for trapped solar particles. The 3-second (repeating) time-lapse featured video was captured earlier this month from Ottawa, Ontario, Canada. It shows the development of a larger-than-Earth prominence as it appears to leak solar plasma back to the Sun, over the course of an hour. What is unusual is that the prominence appears to hover -- more simple and typical prominences form magnetic loops that connect back to the surface. Many hours after this video ended, the hovering prominence disintegrated back into the Sun.