This close-up image of the Sun was taken at the Phoebe Waterman Haas Public Observatory on July 20, 2013 at 11:53 am.
A sunspot group is visible toward the center of the image. These features are caused by increased magnetic activity which keeps hot plasma from rising to the surface. This causes the area to become slightly cooler than the rest of the Sun. Surrounding the sunspot are bright cloud-like features called plages.
On the left edge a large prominence and several smaller ones can be seen. These are caused by magnetic field lines which protrude out of the surface of the Sun and into the atmosphere. Plasma from the Sun travels along each loop, making a bright arc against the dark background of space. The dark lines on the disk of the Sun, called filaments, are also magnetic loops, but they appear dark against the Sun’s surface.
The same features can be seen on the image of the Sun from the next day, carried to the right by the rotation of the Sun.
Telescope: Lunt 100mm hydrogen-alpha
Camera: Lumenera SKYnyx 2-2M