Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       Astra Plinius - celestial bodies
         Universe
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
             (Supercluster) Virgo Supercluster
               (Cluster) Local Group
                 (Galaxy) Milky Way Galaxy veter.
                   (Spiral arm) Perseus Arm
                     4100 (Open cluster) M36 (Aur)
                     4200 (Open cluster) M38 (Aur)
                     4511 (Open cluster) M37 (Aur)
                     5000 (Open cluster) M52 (Cas)
                     9000 (Open cluster) M103 (Cas)