In photographs taken in the spectrum of visible light, the Sun’s magnetic field is invisible. But this image wasn’t taken in our familiar, visible wavelengths, which is why the Sun’s magnetic field is both apparent and beautiful.
The bright white strands in this image are called coronal loops; they’re the lines of the Sun’s magnetic field passing through the corona, the outer layer of gas around the Sun. The blue and yellow patches show the two opposite polarities of the magnetic field.
NASA combined data from two advanced instruments aboard NASA’s Solar Dynamics Observatory to produce this dramatic image, with color added to make the image clearer. The Atmospheric Imaging Assembly, which creates images of the solar atmosphere in 10 different wavelengths every 10 seconds, imaged the coronal loops, while the blue and yellow magnetic field images came from the Helioseismic and Magnetic Imager. The overlay provides a striking look at the invisible force of the Sun’s magnetic field.
[NASA]
Image Credit: NASA SDO