Clustering structure of the δ Set sample from Bowman et al. (2016). The cluster labels are indicated in color and represent the cluster to which the stars are assigned by HDBSCAN based on the density structure of the UMAP components. The “Not assigned” label indicates that the star is seen as noise because it is not close enough to any of the other clusters. The labels from Bowman et al. (2016) are indicated by the marker shapes. Their labels were assigned based on a visual inspection of the light curves and power spectra. These labels were not used during our clustering procedure as it is fully unsupervised. The labels only serve as an indication to better understand the clustering results. The corresponding confusion matrix is shown in Table 1.