Figure 20

Figure 20: Metric coefficient R(r) for the Janis-Newman-Winicour metric. For 1 < g < 1 2, R(r) is similar to the Schwarzschild case g = 1 (see Figure 9). For 1 g < 2, R(r) has no longer a minimum, i.e., there is no longer a light sphere which can be asymptotically approached by light rays.