It is not simply that one wavelength (that image in OP is just the wavelength where it is most visible), look at all of the images and you will see what I believe is called a 'coronal hole' covering most of the side of the sun which is facing us. So far in my 6 months or so of watching the sun daily I have not seen one this large. You can also see a quite spectacular sunspot coming into view on the upper left side. Probably no doom, just fun to look at and watch.

[link to sohowww.nascom.nasa.gov]

[link to en.wikipedia.org]