The narrowband hydrogen-alpha filter used to take this image of the Sun enables us to peer into the chromosphere, the lower region of the solar atmosphere. The image is presented in a false colour palette, chosen both for its aesthetics and to highlight some of the features that show the dynamic and unpredictable nature of stars.
Sunspots are often found in groups and are planet sized regions characterised by an inky dark core, known as the umbra, and a lighter outer section, known as the penumbra. They are caused by disturbances in the Sun's magnetic field and appear dark because they are cooler than the surrounding area. This image shows the two main sunspot groups (3033 and 3055) that w...