The sun is often most interesting to observe at Extreme Ultra-Violet (EUV) wavelengths rather than visible wavelengths. In the EUV, the sunspots and active regions are bright instead of dark and the solar magnetic field can be observed as loops around the active region. Solar physicists and space weather forecasters watch the sun with special EUV cameras mounted on satellites. One such satellite, the NASA Solar Dynamics Observatory (SDO), carries the Atmospheric Imaging Assembly which images the solar atmosphere in multiple EUV wavelengths. By imaging the sun at a resolution of about 1 arcsecond and at a cadence of 10 seconds, this instrument is designed to provide an unprecedented view of the part of the solar atmosphere called the corona. The primary goal of the AIA Science Investigation is to use these data to significantly improve our understanding of the physics behind the activity displayed by the Sun's atmosphere, which drives space weather.
This sequence shows the sun as seen in the 19.3 nm channel of AIA. This wavelength highlights the active regions on the sun and the magnetic structures associated with them. Five days of data were collected from 5-9 September 2011 at a 2.5 minute cadence. These images were stretched and modified to create a more realistic display for the SOS format. It should be noted that the SDO imagers can only see one side of the sun so it is impossible to know what is going on around on the back side. In order to create a full 360 sequence of images, the central part of the sun, where the resolution is the best, was repeated three times to create the appearance of the full sun. You can see that the bright active region appears three times and there is a region where each image overlaps its neighbor creating a slight blurring of the image.