Brightness of Long-Period Comets Observed at Large Heliocentric Distances.
                   The computer catalogue for 1861-1976.
                               by  J. Svoren

    In the next file (catalog2.zip), you can kindly find the computer
catalogue of the brightness of long-period comets observed
also at large heliocentric distances in the years 1861-1976.

    A catalogue of 9 919 magnitude values for 67 long-period comets observed
at heliocentric distances greater than 2.5 AU is enclosed. The catalogue
summarizes visual, photographic and photoelectric magnitudes of the long-period
comets that were observed also beyond 2.5 AU from the Sun whose orbits are well
determined (orbits enable differentiation between old and new comets in Oort's 
sense). The main advantage of the catalogue are complete references enabling to 
go back to the primary sources and also heliocentric and geocentric distances 
and phase angles simplifying a work with data.
    The list contains the dates of observations, the apparent brightness of
comets and the types of magnitudes, the methods, the diameters of objectives
and the light-gathering powers of the telescopes used, the types of
instruments, the names of observers and references to original literature as
well as the calculated values of heliocentric and geocentric distances and
phase angles for the dates of observations.

The catalogue is a part of three articles: 
I. The computer catalogue for 1861-1941
  "Svoren, J.: 1997, Planet Space Sci 45, No.7, 795-797".
II. The computer catalogue for 1945-1957
  "Svoren, J.: 1999, in Evolution and Source Regions of Asteroids and Comets,
  Proc. IAU Coll. 173, Eds. J. Svoren, E.M. Pittich and H. Rickman, Astron.
  Inst. of SAS, Tatranska Lomnica, 255-258".
III. The computer catalogue for 1959-1976
  "Svoren, J.: 2003, in Asteroids, Comets, Meteors, ESA-SP-500, 
  Ed. B. Warmbein, ESA Publ. Division, Noordwijk, in press".

  The catalogue data can be used free but above mentioned papers should be
quoted in each official using of the catalogue or its part.

   The catalogue consists of 70 files: readme.all file as the first, one file 
for each of 67 selected comets, reference file (referenc.dat) and execute file
(catalog3.exe). All these files are packed into the file "catalog2.zip".
     When you use it, please read the readme file as the first.
     The catalogue can be used both in manual and in half-automatic regime.
 
   HALF-AUTOMATIC REGIME

   The executable file "catalog3.exe" works under the MS-DOS compatible
operating systems for PC (including all the versions of MS-WINDOWS) and is 
sent together with the data files and the readme.all file. A required amount 
of memory is 418 KB at least. All data files, readme.all file and catalog3.exe 
file should be placed in the same directory and should not be modified. 
Executing of catalog3.exe file enables to browse in the half-automatic way. 
In this case, notes (if any) and complete references of primary sources are 
shown in two windows.
   All the data files have to follow the same way of writing notes. The
original data files (with the data of comets 1861-1957), shown three years ago,
have been modified (data have not been changed, only a form of notes, of
course). That is why, THE NEW VERSION OF DATA FILES HAS TO BE USED IF YOU
WANT TO WORK WITH THIS NEW COMPREHENSIVE FORM OF THE CATALOGUE (comets 
1861-1976).
                     Sincerely yours
 
                                                   J. Svoren
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