  We present muon spin relaxation ($\mu$SR) and specific-heat versus
temperature $C(T)$ measurements on polycrystalline and single-crystal samples
of the pyrochlore magnet Yb$_2$Ti$_2$O$_7$. $C(T)$ exhibits a sharp peak at a
$T_\mathrm{C}$ of 0.21 and 0.26~K for the single-crystal and polycrystalline
samples respectively. For both samples, the magnetic entropy released between
50~mK and 30~K amounts to $R\ln2$ per Yb. At temperatures below $T_\mathrm{C}$
we observe a steep drop in the asymmetry of the zero-field $\mu$SR time spectra
at short time scales, as well as a decoupling of the muon spins from the
internal field in longitudinal magnetic fields of $\leq0.25$~T for both the
polycrystalline and single-crystal samples. These muon data are indicative of
static magnetic moments. Our results are consistent with the onset of
long-range magnetic order in both forms of Yb$_2$Ti$_2$O$_7$.
