The ground-state band of the Z = 102 isotope No-254 has been identified up
to spin 14, indicating that the nucleus is deformed. The deduced quadrupole
deformation, beta = 0.27, is in agreement with theoretical predictions. Th
ese observations confirm that the shell-correction energy responsible for t
he stability of transfermium nuclei is partly derived from deformation. The
survival of No-254 up to spin 14 means that its fission barrier persists a
t least up to that spin. [S0031-9007(98)08223-4].