XZ80Q is a revised star catalogue for use in predicting and analysing
lunar occultations, replacing the XZ80P catalogue. 

XZ80Q is a revision and expansion of the XZ80P catalogue created by 
Mitsuru Soma in 1999. The revision has ensured that accurate modern
coordinates are used for all stars in the catalogue, as well as the
detection and deletion of false entries. The expansion has increased
coverage to all ecliptic stars listed in Tycho2 with a magnitude
brighter than 12.0, as well as a close-ecliptic expansion (for 
lunar eclipses) of stars in the UCAC2 catalogue brighter than 12.5.

XZ80P had a total of 53919 stars. In XZ80Q, 49 of those stars have 
been deleted as erroneous entries. Another 168 stars have been 
deleted as they were well outside the ecliptic. XZ80Q has 244051 
stars, of which 57265 are in the close-ecliptic expansion. 

This version also includes revision of the associated files of double 
and variable stars, and cross-identifiers for a number of special 
catalogues that were generated in the 80's and 90's for special 
purposes (such as lunar eclipses.)

The catalogue is presented as an ASCII text file. It forms the basis 
for reporting and analysing occultations. It will also be the basis for
software such as winOCCULT and Eric Limberg's Lunar Occultation 
Workbench [LOW] - although both software packages use the catalogue
in a different format.

The catalogue and associated files is downloadable in a single ZIP
archive of 9.72MB. In the ZIP archive is the file
    XZDocumentation.txt
which contains a full explanation of the creation of the XZ80Q catalogue
together with historical notes concerning previous versions of
the XZ catalogue.


Dave Herald
Canberra, Australia
24 August 2003