Variation in the low velocity emission line components of [N II] 6583 Å; from top: 55 314 (solid), JD 55  334 (dot), 55 370 (dash), 55 397 (dot-dash). The emission hole at around  −54 km s^-1, corresponding to the maximum in the narrow [O I] emission, remained constant. This indicates the presence of large density contrasts in the circumstellar material, comparing the  −40 km s^-1 and  −20 km s^-1 features; some weakening appeared also for the  −80 km s^-1 feature. These coincided with the emission/absorption components on Na I D (see text).