Summed Lomb–Scargle (LS) periodogram analysis of the K2 photometry of WD 1145+017 (top panel), and the K2 photometry split in three equal ∼26.6 ﹩\mathrm{day}﹩ sections (bottom three panels). The vertical red dashes denote the A–F periods of Vanderburg et al. (2015). The horizontal blue line marked “﹩{\rm{\Delta }}P﹩” denotes the frequency resolution of the LS periodogram given by ﹩{\rm{\Delta }}P﹩ = 1/T, where T is the duration of the photometry (80 ﹩\mathrm{day}﹩ in the top panel, and ∼26.6 ﹩\mathrm{day}﹩ in the bottom panels).