  We study the impact of a small-scale dynamo in core-collapse supernovae using
a 3D neutrino magnetohydrodynamics simulation of a $15 M_\odot$ progenitor. The
weak seed field is amplified exponentially in the gain region once
neutrino-driven convection develops, and remains dominated by small-scale
structures. About $250\, \mathrm{ms}$ after bounce, the field energy in the
gain region reaches $\mathord{\sim} 50\%$ of kinetic equipartition. This
supports the development of a neutrino-driven explosion with modest global
anisotropy, which does not occur in a corresponding model without magnetic
fields. Our results suggest that magnetic fields may play a beneficial
subsidiary role in neutrino-driven supernovae even without rapid progenitor
rotation. Further investigation into the nature of magnetohydrodynamic
turbulence in the supernova core is required.
