This image of the Sun was taken through a Hydrogen-alpha telescope at 12:19 pm ET on February 24, 2013.
On this day there were several beautiful prominences, including a large one with a double arch. Visitors and volunteers commented that it looked like a Y shape or a whale’s tail. This prominence can be seen sticking out of the Sun’s right side in this photograph.
Prominences are large arches of hot gas that follow magnetic “highways” looping over the Sun’s surface. This “whale tail” prominence was actually a pair of arches situated one behind the other. Our viewpoint was at just the right angle to make the two arches look like a Y shape. Prominences change quickly, though; this formation was gone just a few hours later.
Telescope: Lunt 100mm Hydrogen-alpha
Camera: Lumenera SKYnyx2-2M