COMMISSION 27 OF THE I. A. U.
                  INFORMATION BULLETIN ON VARIABLE STARS
                              Number 3588

                                                        Konkoly Observatory
                                                        Budapest
                                                        16 April 1991

                                                        HU ISSN 0374 - 0676


             VARIABLE STARS IN THE IRAS POINT SOURCE CATALOGUE

   The five-volume Point Source Catalogue of infrared sources resulting from
the work of the Joint IRAS Science Working Group (see Beichman et al. 1988)
contains excellent infrared photometric data and quite accurate positions for
over 245,000 astronomical objects. This extremely valuable catalogue is
accompanied in many cases by "associations" or possible identifications of the
included objects, based almost entirely on positional coincidence. As would be
expected, numerous named and suspected variables are contained in the
catalogue. The purpose of this note is simply to point out that not all of
these variables are so identified. This is not surprising, as it was never
intended. There are at least three reasons for the lack of identification of
many variables. (1) Many catalogues besides the GCVS and the 1982 New
Catalogue of Suspected Variable Stars were used to establish the associations,
and only a single association is cited. Many of the brighter variables, thus,
are identified only by reference to such catalogues as the Smithsonian
Astrophysical Observatory, the Dearborn Red Star, or the Caltech Two-Micron
Survey catalogues. (2) The version of the GCVS used included only those named
variables so designated by the year 1970, and thus the variables in later
naming lists are not noted. And (3) the tabulated positions of many variables
are quite inaccurate, and positional associations are often uncertain or
impossible.
   The extent to which the Point Source Catalogue does not identify named
variables is difficult to estimate. In Scorpius it appears that about 20% of
them are not so designated, while in the more northerly constellations such as
Aries or Bootes the fraction is much larger. It is thus apparent that
researchers seeking infrared photometric data for variable stars should check
the catalogue positions directly instead of relying on the associations given,
which are still useful, of course, for other purposes.


                                       WILLIAM P. BIDELMAN
                                       Warner & Swasey Observatory
                                       Case Western Reserve University
                                       Cleveland, Ohio 44106



Reference:

Beichman, C. A., Neugebauer, G., Habing, M. J., Clegg P. E., and Chester T. J.
        1988, Infrared Astronomical Satellite (IRAS) Catalogs and Atlases
        (Washington: NASA Ref. Publ. 1190). [BIBCODE 1988iras....1.....B ]