Individual and phase-folded joint-fit light curves of the four visits of GJ 3929 b found using FN-PCA detrending using the Erebus pipeline. The eclipse depth is found to be 190 ± 40 ppm for visit 1, 155 ± 34 ppm for visit 2, 60 ± 34 ppm for visit 3, and 97 ± 78 ppm for visit 4. There is a gap during the eclipse for visit 4, due to a scheduling constraint. For the joint fit of all the visits the eclipse depth is 118 ± 22 ppm. The dashed line shows the eclipse timing offset relative to a circular orbit retrieved from the joint fit (54 ± 2 minutes earlier than 0.5 phase). The eclipse time found in the joint fit was used as a Gaussian prior on eclipse time for the individual fits. The rms of residuals is plotted for both the FN-PCA and third-degree polynomial detrendings, showing that it is generally improved by using the FN-PCA.