Pulse profiles of V 0332+53 during the giant outburst in 2004/2005 observed with RXTE. The pulse profiles are sorted chronologically from left to right in the upper panel, then left to right in the lower panel. Energy bands are soft to hard from top to bottom for each observation. The bands (lower energy – upper energy in keV) are given in the diagrams. The letters at the botton of each panel give our identifiers for the observations. The dotted and dashed lines show the ranges in which the symmetry points Φ₁, Φ₂ are found (see Sect. 3).