SSD-T-1-0338-0097-83

           DOCUMENTATION FOR THE MACHINE-READABLE VERSION OF THE
            STRASBOURG CATALOGUE OF GALACTIC PLANETARY NEBULAE
                   (ACKER, MARCOUT, AND OCHSENBEIN 1980)

                                April, 1983

                           Contract NAS 5-27393

                              Robert S. Hill

                               Prepared for:

               National Aeronautics and Space Administration
                        Goddard Space Flight Center
                         Greenbelt, Maryland 20771

                               Prepared by:

                          ST Systems Corporation
                           4400 Forbes Boulevard
                          Lanham, Maryland 20706

                             TABLE OF CONTENTS
                             -----------------

 SECTION 1 - INTRODUCTION ............................................ 1-1
 SECTION 2 - FILE CONTENTS ........................................... 2-1
 SECTION 3 - FILE CHARACTERISTICS .................................... 3-1
 SECTION 4 - REMARKS AND MODIFICATIONS ............................... 4-1

                         SECTION 1 - INTRODUCTION
                         ------------------------

 A COPY OF  THIS DOCUMENT SHOULD  ACCOMPANY EVERY DISTRIBUTED  COPY OF THE
 MACHINE-READABLE CATALOGUE.

 This  document  describes  a  machine-readable  version of the Strasbourg
 Catalog of Galactic Planetary Nebulae (Acker et al., 1981).  The original
 version of  the machine-readable  dataset was  supplied by  the Centre de
 Donnees Stellaires, and has been  reformatted as described in Section  4.
 Most  of  the  information  in  Section  2  is repeated from Acker et al.
 (1981), part 1. Also, the following is quoted directly from that paper:

      The  aim  of  this  catalogue  is  to  provide a list of data
      concerning  all  known  planetary  nebulae  (PN).   The total
      number is 1455  including 1036 listed  in Perek and  Kohoutek
      (PK)  catalogue  (1967),  and  including  including  doubtful
      cases.  The additions come from Sanduleak (1975, 1976), Acker
      and  Marcout  (1977),  Weinberger  (1977),  Peterson  (1977),
      Kohoutek (1978), Stephenson  (1978), Allen (1979),  Murdin et
      al.  (1979), Van den Bergh (1979), Purgathofer and Weinberger
      (1980).

 REFERENCES:

 Acker, A.: 1976, These - Publication de l'Observatoire de Strasbourg,
    vol. 4 fasc. 1.
 Acker, A.: 1978, Astron. Astrophys. Suppl. Ser. 33, 367.
 Acker, A.: 1980, Astron. Astrophys. 89, 33.
 Acker, A., Marcout, J.: 1977, Astron. Astrophys. Suppl. Ser. 30, 217.
 Acker, A., Marcout, J., Ochsenbein, F.: 1980, Centre de Donnees
    Stellaires Bull. No. 18, 84.
 Acker, A., Marcout, J., Ochsenbein, F.: 1981, Astron. Astrophys. Suppl.
    43, 265.
 Allen, D. A.: 1979, Observatory 99, 83-87.
 Aller, L. H.: 1976, Mem. Soc. Scient. Liege. vol. 9, 271.
 Alloin, D., Cruz-Gonzalez, C., Peimbert, M.: 1976, Astrophys. J. 205,
    74.
 Higgs, L. A.: 1971, Publ. Astrophys. Branch, Ottawa, vol 1, no. 1.
 Johnson, H. M.: 1976, Astrophys. J. 208, 127.
 Kaler, J. B.: 1978, Astrophys. J. 226, 947.
 Kohoutek, L.: 1978, in IAU Symp. 76, Y. Terzian (D. Reidel Publ Co.
    Dordrecht, Holland).
 Murdin, P., Clarck, D. H., Haynes, R. F.: 1979 Mon. Not. R. Astron.
    Soc. 189, 459-463.
 Perek, L., Kohoutek, L.: 1967, Catalogue of Planetary Nebulae,
    Czechoslovak Academy of Sciences

                                    1-1

 REFERENCES (continued):

 Peterson, A. W.: 1977, Publ. Astron. Soc. Pac. 89, 129.
 Purgathofer, A., Weinberger, R.: 1980, Astron. Astrophys. 87, L5.
 Sanduleak, N.: 1975, Publ. Warner Swasey Obs., vol 2, no 1.
 Sanduleak, N.: 1976, Publ. Warner Swasey Obs., vol 2, no 3.
 Stephenson, C. B.: 1979, Publ. Astron. Soc. Pac. 90, 396.
 Van den Bergh, S.: 1979, Astrophys. J. 227, 497.
 Weinberger, R.: 1977, Astron. Astrophys. Suppl. Ser. 30, 355.

                                    1-2

                         SECTION 2 - FILE CONTENTS
                         -------------------------

 A byte-by-byte description of the contents of the catalogue is given in
 Table 2-1.  The information in the "Description" Column is derived mainly
 from the published version whenever possible.  The "Suggested Format"
 column is for FORTRAN-formatted reads.

                    Table 2-1.  File Contents (1 of 2)
                  Strasbourg Catalog of Planetary Nebulae

                                                              SUGGESTED
 BYTES                          DESCRIPTION                    FORMAT
 -----                          -----------                   ---------

  1- 9        Perek-Kohoutek (PK) number or number of the
              same form.  This  catalogue  contains  1455
              records.  The records  are ordered by right
              ascension (bytes 10-17).  Note:  references
              are given after Section 1 above.

              1-3    Galactic  Longitude,  (system II) in      I3
                     degrees.

              4-9    Galactic  Latitude,   (system II) in      F6.2
                     degrees.  In all cases but one, byte
                     9   is   blank.    In   that   case,
                     PK 358 + 3.10 (zero  in  byte 9)  is
                     differentiated from PK 358 + 3.1.

      10-26   Equatorial coordinates (1950).  These agree
              with the radio coordinates of Higgs  (1971)
              to within 0.01  minutes of right  ascension
              and 0.1 arcminutes of declination.

              10-11  Hours of right ascension                   I2
              12     Blank                                      1X
              13-17  Minutes of right ascension                 F5.2
              18     Blank                                      1X
              19     Sign of declination ("+" or "-")           A1
              20-21  Degrees of declination                     I2
              22     Blank                                      1X
              23-26  Arcminutes of declination                  F4.1

 27           Blank                                             1X

 28-32        Visual magnitude

              28     ">" or blank                               A1

              29-32  Visual   magnitude   of    planetary       F4.1
                     nebula, integrated over its surface.
                     A blank field (value 0.0)  indicates
                     no data.

 33           Blank                                             1X

                                    2-1

                    Table 2-1.  File Contents (2 of 2)
                  Strasbourg Catalog of Planetary Nebulae

                                                              SUGGESTED
 BYTES                          DESCRIPTION                    FORMAT
 -----                          -----------                   ---------

 34-37        Angular size. Blank field indicates no data.

              34     Morphology indicator: "<" for  star-       A1
                     like  appearance,  ">"  for  fainter
                     spherical envelope  (Higgs 1971)  or
                     else blank.

              35-37  Average  diameter  of  the brightest       I3
                     part  of  the  planetary  nebula, in
                     seconds of arc.

 38           Blank                                             1X

 39-42        Mean radial  velocity  (Acker 1978,  1980).
              Blank field indicates no data.

              39     Sign: "+" or "-"                           A1

              40-42  Mean radial velocity in km/s               I3

 43           Blank                                             1X

 44-49        Magnitude of central star.

              44     ">" or blank                               A1

              45-48  Magnitude:  either from Kaler (1978)       F4.1
                     (B value), from Aller (1976), or the
                     average   value   from   Perek   and
                     Kohoutek (1967).

              49     "V" for variable, otherwise blank          A1

 50-52        Expansion velocity of the planetary nebulae
              (Acker 1976, Johnson 1976, Alloin et al.
              1976).

              50     "<", ">", or blank                         A1

              51-52  Velocity in km/s                           I2

                                    2-2

                     SECTION 3 - FILE CHARACTERISTICS

The information in  this section describes  the logical structure  of the
catalogue file  or files.  A reminder  to the user is included  of  the 
PHYSICAL  tape  attributes  of  which knowledge may be required to read a tape
copy of the catalog.

                     Table 3-1.  File Characteristics

            Strasbourg Catalogue of Galactic Planetary Nebulae
                   (Acker, Marcout, and Ochsenbein 1981)

           Catalogue Abbreviation                    PLN
           Number of Files                           1
           Logical Record Length (Bytes)             52
           Record Format (IBM OS/JCL)                Fixed
           Total Number of Logical Records           1455

 Other attributes of the tape will vary from copy to copy, as their values
 are discretionary, or else depend on the computer for which the tape was
 copied.  These include the following:

           Number of Tracks
           Density (Bits per Inch)
           Blocksize (Bytes)
           Blocking Factor (= Number of logical Records per Block*)
           Total Number of Blocks
           Character Code

 The values of these parameters for your tape are supplied separately.
 You may wish to write them in above.

                                    3-1

                   SECTION 4 - REMARKS AND MODIFICATIONS

 The orignal version  of this catalogue  was received by  the Astronomical
 Data Center (ADC), NASA Goddard  Space Flight Center, in July  1982, from
 the  Centre  de  Donnees  Stellaries  (CDS).   The  present  version  was
 generated from  the CDS  version, the  purpose of  all the  modifications
 being to adapt the file for  use with FORTRAN programs.  (No data  values
 were altered.)  To this end, the following were done:

      (1)  Commas  in  numbers  with  decimal  fractions were made decimal
           points to conform with FORTRAN usage.

      (2)  Decimal points were  added to integral values of data that will
           be read with "F" formats according to Table 2-1 above.

      (3)  A  very few data  appeared to be  misaligned within the record,
           e.g., '7 ' for ' 7'.  These data were realigned.

      (4)  The one  variable  central  star  (PK 289-0.1) was indicated by
           "VAR" in the magnitude field.  This was changed to a "V" to the
           right of the magnitude field.

      (5)  The  CDS   catalogue-number   tag  at  the  beginning  of  each
           record  was  removed,  since  this  version is not identical in
           format to the CDS version.

 In addition,  the catalogue  data were  checked by  a FORTRAN program for
 valid range, such as  right ascension between 0  and 24 hours.  No errors
 were detected by this check.

 REFERENCES:  See after Section 1.

                                    4-1