A uniform system of identifications


The most important point in developing catalogues and data compilation is that each star should be recorded under one and only one identification number.

However the variety of stellar identifications available and really used in the literature presents a difficult problem for anyone wishing to undertake a data compilation in any field of astronomy. The worst case seems to be that of the UBV photometry, considering its worldwide use and the limiting magnitude reached in this system. If one intends to include all possible stars in a compilation, one will face serious problems for faint field stars and stars in star clusters (open and globular).

A number of more fundamental catalogues have been chosen to define the basic identifications of various kinds of stars. We have then tried to find an identification for each star in the basic catalogues first, and kept the original one if nothing else could be found. The SIMBAD database can be used to look for the existing identifications for each object.

The code-numbering system

Full or abbreviated names, such as HD, Gliese or LTT are very practical for printed catalogues, but not for computer work. Until now there has been no real solution to this essential problem. None of the methods used in available catalogues fits our needs. We have therefore designed a code-numbering system flexible enough to include any kind of stellar designation.

General Principles

Obviously it is not always possible to retain the originally published identifications because too many possible designations are used for each star by the astronomers. It is highly unfortunate that no real consensus has yet emerged from common practice to define primary identifiers to be used in priority.

Accordingly, one of our main contributions in building the photometric catalogues is to collect the data under a sole designation for each star. The amount of work needed to carry out such a project represents undoubtedly one of the most important part of the whole chain.

The identification principles continuously maintained during this work are recalled below.

General specifications

General specifications for star designation have been proposed by the Task Group on Astronomical Designation of IAU Commission 5.

The Dictionary of Nomenclature of Celestial Objects presents full references and usages of about 4000 acronyms.

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Last update:18 March 1996