The extended arms of some galaxies are too dim in visible light for most telescopes to detect, but
they emit a greater amount of UV light. Also, the cosmic background is much darker at UV wavelengths
than it is for visible light. Because the sky is essentially black in the UV, far-UV enables you to
see these very faint arms around the outsides of galaxies as is demonstrated in the GALEX satellite
image on the right. Never the less and under a high contrast stretch these very faint contorted arms
are indeed visible in this 7.5hrs worth of Luminance (visible light) exposure through the 12" F3.8 Astrograph.

Read more about the image by the Galaxy Evolution Explorer satellite here:
http://www.galex.caltech.edu/media/glx2007-01f_img01.html