The sun, as imaged in various wavelengths...

The sun, as imaged in various wavelengths...  Via APOD, of course.  The colored wedges show longer-to-shorter wavelengths as you move clockwise from the 10 o'clock to the 2 o'clock wedges.  Full resolution image here.  We're starting to accumulate a rather impressive set of solar observational technology, much of it in space, but some still on Earth...