P/2016 G1 on 2016 April 3, May 12, and May 31. The green dots mark clumps on the arc feature. The small red dots correspond to the synchrone trajectories of small dust (submitted to radiation pressure) emitted from some of the clumps on March 6. The position of large particles emitted on March 6 on a cone with half-opening 40° and centred on (long., lat.) = (68°, −15°) are over-plotted for velocities ranging from 1.625 to 2.750 m s⁻¹. The solid line corresponds to 2.5 m s⁻¹.