Black Sun = Black Hole

The Neo-Nazi Germanic black sun symbol depicts black hole. The doctrine of the Black Sun, reaching back to ancient Sumer and Akkadia, is that there are two suns, the "white" sun, the sun that we see at the center of our physical solar system, and the "black" sun, a "hidden" sun of (spiritual) illumination. In some versions of the myth, it is thought to reside at the center of our galaxy. Other embellishments place it as one of the causes of the immortality and reincarnation of the soul.

More information on the Third Reich and the Black Sun: http://www.bibliotecapleyades.net/sociopolitica/reichblacksun/chapter11.htm