Date: Mon, 3 Feb 1997 18:15:46 +0100
From: Paul Schlyter 
To: robinson@sky.net, asunshine@netzone.com
Subject: Re: Zodiacal Catalogue 

1. First round was back in 1981-82.  I settled for a subset
containing only stars brighter than mag 6.0.  This was some 600 out
of those 3539 stars.  This was done on an Apple II+ 8-bit
microcomputer!  I used those data to predict occultations of stars
brighter than mag 6.0 visible from my country, Sweden, from 1984 and
onwards -- occultation predictions for my area of the world had been
next to non-existent before.

2. Next time was around 1984-85, again on that Apple II+, although
this time I had a somewhat more decent OS (CP/M instead of Apple
DOS), and I had also obtained a nicer keyboard.  This time I typed
in everything from Robertson's original ZC.  However I never used
these data, because:

3. ILOC then published ZC 2000.0.  I obtained a copy, and decided to
type that in too.  Now it was 1986-87, and I had obtained a PC.  ZC
2000.0 also listed both ecliptic and equatorial coordinates for each
star, which offered an excellent way to check for typing errors: I
typed in both of them, then I ran a program that read both, converted
one into the otherm and then compared with what I had typed for the
other.  Apart from round-off errors they should be equal.  I think I
caught all typing errors here, but of course I also proofread it all.


The data that I typed in in the third round I then used to predict
occultations with greater accuracy, as well as grazing occultations,
as seen from Sweden, from 1989 and onwards.


In 1995 I made these data publicly available at:

    ftp://nic.funet.fi/pub/astro/dbases/stars/zc_a.lzh  and  zc_b.lzh
    These web addresses are now outdated - current web addresses are:
    http://www.ursa.fi/extra/ohjelmarekisteri/show_prog.php4?id=466&version_id=1&lang=en
    http://www.funet.fi/pub/astro/dbases/stars/

You'll need the program LHA.EXE to unpack these.  Or you can use
Filzip at http://www.filzip.com/, it can handle LZH archives.


Today I checked them once more, added the file FILES.LST (reproduced
below). zipped it all up into one file, ZC.ZIP (413014 bytes), and
now it's also available at:

   http://stjarnhimlen.se/zc/zc.zip

Sorry, but there's no way to ftp it from there, you must use a web
browser and the http protocol.  If you only have access to ftp,
grab it at nic.funet.fi instead.


And finally, a copy of FILES.LST in zc.zip  (not present in zc_a/b.lzh):

-------------------------------------------------------------------------
ZC1950.DAT      The original Zodiacal Catalogue, from APAE
ZC2000.DAT      The 2000.0 version of the Zodiacal Catalogue, from ILOC
ZC2000O.DAT     Same as above but ordered in 1950.0 RA
ZCNAM.DAT       Names of stars in ZC
ZC_D            Double stars in ZC
ZC_DV           Variable stars in ZC
ZC_V            Variable stars in ZC
ZC_DSKY         Zodiacal Deep-Sky objects
ZCRADIO         Zodiacal radio sources
ZC_NUT          The IAU theory of Nutation
PREC            Precession matrices
-------------------------------------------------------------------------

 
----------------------------------------------------------------
Paul Schlyter,  Grev Turegatan 40,  S-114 38 Stockholm,  SWEDEN
e-mail:  pausch@stjarnhimlen.se
WWW:     http://stjarnhimlen.se/english.html