What is SIMBAD, and what is it not ?
The purpose of Simbad is to provide information on astronomical objects
of interest which have been studied in scientific articles.
Simbad is a dynamic database, updated every working day.
It provides the bibliography, as well as available basic information
such as the nature
of the object, its coordinates, magnitudes, proper motions and parallax,
velocity/redshift, size, spectral or morphological type, and the multitude
of names (identifiers) given in the literature.
The CDS team also performs cross-identifications based on the
compatibility of several parameters, in the limit of a reasonably
Simbad is a meta-compilation built from what is published in the
literature, and from our expertise on cross-identifications.
By construction it is highly inhomogeneous as data come from
any kind of instruments at all wavelenghts with any resolution and
astrometry, and different names from one publication to another.
Simbad is not a catalogue, and should not be used as a catalogue. The CDS
also provides the VizieR database which contains published lists of objects,
as well as most very large surveys. The idea now is to use both
Simbad and VizieR as completary research tools.