  Magnetic fields on small scales are ubiquitous in the universe. Though they
can often be observed in detail, their generation mechanisms are not fully
understood. One possibility is the so-called small-scale dynamo (SSD).
Prevailing numerical evidence, however, appears to indicate that an SSD is
unlikely to exist at very low magnetic Prandtl numbers ($Pr_M$) such as are
present in the Sun and other cool stars. We have performed high-resolution
simulations of isothermal forced turbulence employing the lowest $Pr_M$ values
so far achieved. Contrary to earlier findings, the SSD turns out to be not only
possible for $Pr_M$ down to 0.0031, but even becomes increasingly easier to
excite for $Pr_M$ below $\simeq\,$0.05. We relate this behaviour to the known
hydrodynamic phenomenon referred to as the bottleneck effect. Extrapolating our
results to solar values of $Pr_M$ indicates that an SSD would be possible under
such conditions.
