Line-of-sight velocities and measurement uncertainties for stars in Eridanus 2, relative to the intrinsic mean velocity, as a function of signal-to-noise ratio. The possible cluster members are marked with triangles, pointing upwards for those with a high membership probability (∼80−90%) and downwards for the one source with a lower probability (∼60%). The other stars are marked with circles. The black horizontal lines indicate the intrinsic velocity dispersion. The most likely scenario, where all possible cluster member stars are indeed cluster members, is shown. Left: velocities for member stars of the cluster. Right: velocities for stars in the bulk of Eridanus 2.