Since now, the historical list of object
types is replaced by this reorganized list, based on physical
properties, and on the evolutionary stage for stars. It enable a more
interactive search, and provide minimal definitions. The hierarchies
between object types evolve: for instance, a RR Lyrae Star still be in the
hierarchy of Variable Stars, and also in the hierarchy of Horizontal Branch
If you are using the hierarchies in scripts, you might have to adapt
your scripts to the new description.
The Object Type in Simbad is defined as a hierarchical classification, which emphasizes the physical nature of the object rather than a peculiar emission in some region of the electromagnetic spectrum or the location in peculiar clusters or external galaxies. Therefore objects are classified as peculiar emitters (Radio, IR, Red, Blue, UV, X or gamma) only if nothing more about the nature of the object is known, i.e. it cannot be decided whether the object is a star, a multiple system, a nebula or a galaxy.
Each class has normally a standard designation, a condensed one (used in tables) and an extended explanation.