This is The Southern Galaxy Catalogue, version 1.21, dated November 1993.  The
distribution includes seven files:

    sgc12.01 -- SGC, 00 hr to 07 hr 43 min
    sgc12.02 -- SGC, 07 hr 43 min to 18 hr 29 min
    sgc12.03 -- SGC, 18 hr 29 min to 23 hr 59 min
    sgc12.xmp -- a short example file for SGC.
    bugs.sgc -- Errata (all errors listed have been corrected in this version)

    sgc12.txt -- SGC, complete
    sgcdoc.txt -- This file.

All are available as 7-bit ASCII files with UNIX line endings.  MS-DOS 
versions of the first five files are in the zipped archive sgc.zip.  Both 
versions contain identical data.  

Here is the format, identical to that in the printed version.

 RA (1950.0) Dec     l     N/I/A         Type       T n_T   L n_L  logD  logR nD
    (2000.0)         b     ESO                      w_T     w_L     w_D   w_R
18 28 57 -56 46.2  338.53  I4719         .SAS8P.   8.0 2   6.0 1   1.38  0.12  2
   33 12 -56 43.9  -20.03  183- G  2                2.0     1.0     2.0   2.0   
18 28 58 -58  0.7  337.28  I4717         .S..3?/   3.0 3           1.43  0.51  3
   33 18 -57 58.4  -20.44  140- G 24                0.75            3.0   3.0   
18 29 11 -58 26.6  336.86  I4720         .SBT7..   7.0 1   6.0 1   1.66  0.35  1
   33 32 -58 24.3  -20.61  140- G 25                1.0     1.0     1.0   1.0   
18 29 14 -41 32.9  353.33  A1829-41      .SXT5*.   5.0 1   3.0 1   1.60  0.15  1
   32 46 -41 30.6  -14.36  336- G  3                0.5     0.5     1.0   1.0   
18 29 21 -60 10.0  335.12  I4718         .S..3*.   3.0 1   5.0 1   1.58  0.30  1
   33 50 -60  7.7  -21.19  140- G 26                0.5     0.5     0.5   0.5   

A brief explanation of the columns:

Columns 1, 2, and 3, lines 1 and 2:  Position, usually from ESO, sometimes
   not.  The positions from Spellman, Madore, and Helou (PASP 101, 360, 1989)
   have been entered.  All most all galaxies have Notes in the printed
   version.

Column 4, lines 1 and 2:  Names from NGC, IC, and RC2 (line 1); from ESO (line
   2).  If the galaxy is not in ESO, the Southern Sky Survey Field number
   alone is listed on line 2.  This, or the ESO name, is followed by an "r" if
   there is a Remark in the printed version about the field containing the
   galaxy.

Columns 5 and 6, line 1:  Coded revised Hubble type (column 5) using the
   coding conventions of RC2 and RC3; and the corresponding numerical Hubble
   stage code, followed by the number of plates on which the type was
   estimated (column 6).  Column 6, Line 2 contains the weight of the
   numerical type on an arbitrary scale from 0 (no type) to 4 or 5 (type
   estimated on 4 or 5 plates, with no uncertainty noted).

Column 7, lines 1 and 2:  Coded numerical luminosity class, followed by the
   number of plates on which the class was estimated (line 1), and the weight
   of the luminosity class (same scale as the type weight).

Columns 8, 9, and 10, lines 1 and 2:  Base 10 logarithm of the major axis
   diameter (D in units 0.1 arcmin as in RC1, 2, and 3) and its weight (column
   8); the base 10 logarithm of the axis ratio (D/d) and its weight (column
   9); and the number of plates on which the diameters were measured (column
   10).  The measured isophote is approximately 27.0 B-mag arcsec^-2.
   Formulae to reduce these data to the standard isophote at 25.0 B-mag
   arcsec^-2 are given in RC3.

See the printed version (University of Texas Astronomy Department Monograph in
Astronomy No. 4, 1985, by Harold G. Corwin, Jr., Antoinette de Vaucouleurs,
and Gerard de Vaucouleurs) for more information and details.

Latest update:  2 Dec 2012.