from discover magazine---
"A Ring of Light Around the Sun
Photographer Miloslav Druckmuller artificially removed the blue sky around the sun's surface in this image of an eclipse. The result reveals the green hues of the inner ring, or inner corona, which gets its tint from a form of highly ionized iron known as "coronium."
In this photo, the corona becomes redder the farther it is from the sun. That's because dust particles deflect shorter wavelengths of light more than longer wavelenghts, so only long-wavelength light--i.e., red--finds its way to the camera."
Image: Thierry Legault
When the Sun's Surface Erupts
Arc-like solar prominences like these form when hot gaseous matter erupts from the sun, then is drawn back to the solar surface by strong magnetic fields.
Solar prominences, which are the most common solar activity, don't disappear instantaneously; in fact, they can last for months. They can also extend for thousands of miles above the solar surface and release the gas they contain into space.