Predicted N-band fluxes for 1989 ML for a range of albedos (red line) and diameters (black line). The horizontal dashed line corresponds to the 5σ flux we would have detected in ∼47 minutes of integration time. The red line flux solutions were computed for a sphere with radius obtained from the E. F. Tedesco et al. (1992) relationship and assuming the JPL-Horizons H_V solution. The black line flux solutions were computed for various sphere sizes with a fixed p_V of 50%. We conclude that this object must have an albedo higher than 0.25 and a diameter smaller than 400 meters.