Degeneracy pressure—the pressure caused by the Pauli
exclusion principle of quantum mechanics—is manifested by
four types of astronomical object: the giant gaseous planet,
the brown dwarf, the degenerate dwarf, and the neutron star.
The first-three objects constitute the subclass of degenerate
objects that are supported by electron degeneracy pressure.
The neutron star is the subclass of degenerate objects supported
by neutron and proton degeneracy pressure.  The degenerate
dwarf and the neutron star are two of the three endpoints
of stellar evolution (the third endpoint is the black hole).
Binary star systems containing a degenerate object are the
most brilliant systems in the Galaxy.