Relative intensity images of the comet C/2018 DO4 (Lemmon) in the R filter obtained on October 03, 2019 (top), and on October 05, 2019 (bottom), at Terskol Observatory. (a) Direct images of the comet with the isophots differing by a factor . (b) Image processed by the rotational gradient method (Larson & Sekanina 1984). (c) Image to which the azimuthal average method was applied (Samarasinha & Larson 2014). The arrows show the directions to the Sun (⊙), north (N), east (E), and the negative velocity vector of the comet projected onto the sky plane (V). Negative distance is in the solar direction.