Spatial distribution of the H₂O maser features toward NML Cyg from VLBA observations at five epochs. Each maser spot is represented by a letter label and a filed circle whose area is proportional to the logarithm of the flux density, using the position and flux density from the epoch at which it was first detected. The color bar denotes the V_LSR range from −25 to +25 km s^-1. The reference maser spot is in feature B, located at (0, 0) mas. (This figure is available in color in electronic form.)