The Urantia Book tells us that there is a lone star at the center of the Crab nebula which is the mother sphere, and had its origin in a nova explosion occurring 900 years ago. The existence of a mother sphere for this nebula was demonstrated in 1967 with the detection of a pulsar now known to be a neutron star.
REFERENCES: The Urantia Book, page 464; Kaufmann, “The Universe”
Urantia Evidence 