8 Nomenclature

8.1 The dictionary of nomenclature

Designations of astronomical objects are often confusing. A complete list of astronomical designations has been collected and published by Lortet et al. ([1994]) in the Dictionary of Nomenclature of Celestial Objects outside the Solar System.

This information is available on-line through the info command, or on the WWW. This service is the electronic look-up version of the Dictionary which is now under the responsibility of CDS. It is kept up-to-date on a weekly basis; about 15 new acronyms are incorporated every week.

The Dictionary currently provides full references and usages about some 5000 different acronyms. It is used by the International Astronomical Union as a reference for its recommendations related to nomenclature.

   
8.2 The sesame module

The sesame module is used inside SIMBAD for the management of possible variations in the naming of astronomical objects. It is based on a list of rules, written as regular expressions, allowing translation of the submitted name into its SIMBAD canonical form; it is only made visible to the user when a message mentions the submitted syntax and its translation.

There are cases where ambiguities cannot be solved. This is actually specific to the broad context of SIMBAD. Let us give an example: in the context of extragalactic objects "N'' is a possible abbreviation for "NGC'' (accepted by NED); but people studying Novae would frequently use "N'' as an abbreviation for Nova, people studying H II regions would use it for naming nebulae in the Magellanic Clouds (LHA 120-N or LHA 115-N), and "N'' has also been found in the literature for cluster stars studied by Nordlund in NGC 2099 (Cl* NGC 2099 N), for stars studied by Neckel ([N78]), or even for "New'' parts of the galaxy NGC 1275 ([NJS93] in SIMBAD). When a name like "N 1992'' is submitted to SIMBAD the ambiguity cannot be solved without requesting additional information from the user.