| Comment: |
| Obsoleted by I/238; Stellar Parallaxes, containing 15349 parallaxes for 7879 stars, has ; been prepared at the Yale University Observatory. In this edition 1480 ; stars have been added to those contained in the previous edition of ; the catalog by Jenkins (1952, 1963). This relatively small increase in ; the number of stars is more than compensated for by the increased ; accuracy of the newer trigonometric parallaxes. ; \par ; The authors have attempted to include here all trigonometric ; parallaxes made available to them by March 1991 and will provide for ; each listed parallax in the final version the reference to its source ; of publication. ; \par ; For each star it lists the equatorial coordinates for B1900 and the ; secular variation for 100 years, the proper motion in x and y, the ; weighted average absolute parallax and its standard error, the number ; of parallax observations, the quality of interagreement among the ; different values, the visual magnitude, and various cross ; identifications with other catalogs. The B1900 equinox has been ; maintained to avoid assigning yet another star number. Ancillary ; information, including UBV photometry, MK spectral types, data on the ; variability and binary nature of the stars, orbits when available, and ; miscellaneous information to aid in determining the reliability of the ; data, will be listed in the final version. ; \par ; The relative parallaxes are corrected to absolute parallax using newly ; computed corrections that are based on an improved model of the ; galaxy. An analysis of the resulting absolute parallaxes has been made ; to study the accidental and systematic errors of the parallaxes. The ; results of that investigation are used to arrive at a weighting system ; for the catalog, which then yields weighted absolute parallaxes for ; each star. The weighting system is still under investigation; ; therefore, the weighted parallaxes may change a bit in the final ; version. ; \par ; Printed copies of the catalog will be available from the Yale ; University Observatory when the work has been completed (late 1993?). ; \par ; See the file cdrom.doc which provides the original documentation by ; W. van Altena. ; catalog 8573x191 The Preliminary Catalogue; (see also Note 1 below) |