Vector point diagram (left), equatorial coordinates (middle), and CMD (right) of the 486 members selected by HDBSCAN for the Roslund 6 open cluster. After an outlier threshold corresponding to 3.33 following the methodology presented in Sect. 3.3, the sample reduces to 429 with 57 stars identified as outliers. The cluster members and outliers are marked by circles and triangles, respectively. The colour bar indicates the Mahalanobis distances.