Observations of L1527 in Ks-band from December 2007 to April 2014 shown as inverse gray scale. The contour levels are 3.5 × n where n is the set of numbers 0.1, 0.2, …, 1.0. As stated in Sect. 3, the primary features of the scattered light nebulae during this observation run are the western lobe’s emergence and the gradual transition toward a more symmetric brightness distribution of the cavities. The color bar shown in the lower right panel is in units of MJy sr⁻¹.