This would be enough information to draw an H-R diagram for the cluster. We could plot color, spectral type, or surface temperature on the horizontal axis—all three are related to the star’s temperature. If we didn’t know the distance to the cluster, we could not convert apparent magnitude into absolute magnitude, but we could still plot an H-R diagram using apparent magnitudes on the vertical axis. All of the stars are at about the same distance and thus have the same distance modulus. Plotting apparent magnitude instead of absolute magnitude would not change the distribution of dots in the diagram.