Credit: Royal Swedish Academy of Sciences - Göran Scharmer and Mats Löfdahl (sunspots) and NASA/SDO and the AIA, EVE, and HMI science teams (coronal loops).
Active regions on the Sun are places where the Sun's magnetic field is disturbed. These regions frequently spawn various types of solar activity, including explosive "solar storms" such as solar flares and coronal mass ejections (CME). Dark sunspots are visual indicators of active regions. High-energy phenomena associated with active regions make these areas bright in ultraviolet and X-ray images of the Sun. Dramatic features such as coronal loops and solar prominences appear around active regions. The images above show a closeup view of sunspots and the active region around them (left) and an ultraviolet view of coronal loops in the Sun's atmosphere above an active region (right).