Feature importance ranking, by the amount the validation ℒ₁ increases after permuting that feature. The CNN 4 features come from the ResNet50 that was retrained on M/L (the rightmost network in Fig. 3). All luminosity features are derived from the raw (star subtracted but not scaled) images, as described in Sect. 3.2. Top: standard predictor as described in Sect. 3, using all features. Bottom: a (freshly trained) predictor which does not make use of CNN 4.