Composite images of 311P/PanSTARRS. These images were taken during 2013 and 2014, and the specific date is marked in the upper left corner of each panel. The arrow marked with N denotes the direction of north, and the arrow marked with E denotes the direction of east. The arrows labeled with v and the solar symbol show the directions of 311P’s motion and the solar orientation, respectively. A black dashed line denotes the brightest streamer of each tail, which limits the morphology of the tail together with the two adjacent red dashed borderlines. Due to the fading of the dust tail on 2014 February 11, only streamers with an S/N greater than 5 is displayed in the bottom-left panel.