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                                                           NSSDC/WDC-A-R&S 84-18












                DOCUMENTATION FOR THE MACHINE-READABLE VERSION


                                      OF


                          THE HENRY DRAPER CATALOGUE


                                (EDITION 1985)








                    Nancy G. Roman and Wayne H. Warren Jr.











                                February 1985







                 National Space Science Data Center (NSSDC)/
          World Data Center A for Rockets and Satellites (WDC-A-R&S)
                National Aeronautics and Space Administration
                         Goddard Space Flight Center
                          Greenbelt, Maryland  20771















                DOCUMENTATION FOR THE MACHINE-READABLE VERSION

                                      OF

                          THE HENRY DRAPER CATALOGUE

                                (EDITION 1985)








                                   ABSTRACT



An updated, corrected and extended machine-readable version of the  catalog is
described. Published and unpublished errors discovered in the previous version
have been corrected; letters indicating supplemental stars in the BD have been
moved to a  new byte to distinguish them from double-star components;  and the
machine-readable portion of The Henry Draper Extension (HDE) (HA 100) has been
converted to  the same  format as the main catalog, with additional data added
as necessary.















                                      ii

                              TABLE OF CONTENTS



Section 1 - INTRODUCTION AND SOURCE REFERENCES ......................     1- 1
Section 2 - FILE CONTENTS ...........................................     2- 1
Section 3 - FILE CHARACTERISTICS ....................................     3- 1
Section 4 - REMARKS, MODIFICATIONS, ACKNOWLEDGMENTS AND REFERENCES ..     4- 1




                                LIST OF TABLES

Table

  1  File Contents ..................................................     2- 1
  2  File Characteristics ...........................................     3- 1
  3  Explanatory Notes to Individual Changes ........................     4- 3
  4 *Changes from the Original Machine Version ......................     4- 4
  5  Stars Deleted from the Catalog .................................     4- 3
  6 *Records Now Out of Right Ascension Order .......................     4-15
  7  Additional Errors Still Present in This Machine Version ........     4-16

  [See the ADC hardcopy documentation for these tables, ed.]






























                                     iii

                SECTION 1 - INTRODUCTION AND SOURCE REFERENCES


Early in this century, Miss Cannon undertook to classify all stars to the
faintest possible magnitude limits on the objective-prism plates available to
her.  Although the faint limit varies from plate to plate and the southern
plates were superior to the northern ones (Hoffleit 1985, private
communication) a realistic value appears to be approximately m(pg) = 9. The
resulting spectral types were published in The Henry Draper Catalogue (HD,
Cannon and Pickering 1918-1924).  Later, she classified somewhat fainter stars
in a number of regions of the sky.  This work was completed by Mrs. Mayall and
published as "The Henry Draper Extension" (HDE, Cannon 1925-1936; Cannon and
Walton Mayall 1949).  A machine version of the HD and of the first volume of
HDE was originally prepared under the supervision of D. Hoffleit at the Yale
University Observatory some years ago (Hoffleit 1967; Gottlieb and Hoffleit
1969), and was subsequently updated with known errors (including some in the
printed catalog) at the Astronomical Data Center (ADC) in 1976.  The current
version of the HD contains the corrections for all errata known to us and/or
published up to the date of this version (February 1985), various errors
forwarded to us by colleagues, and errors discovered at the ADC during the
course of this work.  In addition, the regions of the HDE (1925-1936) for the
declination zones +50 to +59 degrees and for the Magellanic Clouds have been
changed to the same format as the basic catalog.  Right ascensions and
declinations have replaced the X,Y coordinates in the Magellanic-Cloud region.
This version of the machine-readable HD/HDE does not contain the last volume of
the HDE (1949) because no positions are currently available in machine form for
stars in the range HDE 272151-359083.

This machine version of the HD catalog has intentionally been prepared to
conform as closely as possible to the original published catalog, i.e., the
data have not been updated with more modern positions, magnitudes, or spectral
types, since those data can be found in other machine-readable catalogs.  The
intent was to prepare and archive the catalog in essentially original form,
except for the correction of major errors and the identification of duplicate
entries (where the same star has been assigned more than one HD number).  For
ease of use and to make possible the addition of numbers from the Cape
Photographic Durchmusterung in the zones -18 to -52 degrees and the Cordoba
Durchmusterung in the zones -53 to -89 degrees when no other DM numbers exist
(not allowed for in the original HD, nor in the previous machine catalog) the
Durchmusterung numbers have been expanded to their full representation and the
correct prefixes added (BD, CD, CP); thus, codes for DM numbers in italics
have been removed and the correct zones inserted.

This document describes the new version of the machine-readable Henry Draper
Catalogue.  It outlines the procedures used to correct and extend the previous
version; it is intended to enable users to read and process the data without
problems and guesswork.  For more detailed descriptions of the history of the
HD, the Harvard spectral classification system, and other data contained in
the original published catalog, the source references and their bibliographies
(given in the texts only) should be consulted.  A copy of this document should
accompany any machine version of the catalog originating from the Astronomical
Data Center.



                                     1-1

SOURCE REFERENCES

Cannon, A.J. 1925-1936, The Henry Draper Extension, Ann. Astron. Obs. Harvard
  College 100.

Cannon, A. J. and Pickering, E. C. 1918-1924, The Henry Draper Catalogue, Ann.
  Astron. Obs. Harvard College 91-99.
















































                                     1-2

                           SECTION 2 - FILE CONTENTS


A byte-by-byte description of the contents of the machine-readable Henry
Draper Catalogue is given in Table 1.  A suggested Fortran 77-type format
specification for reading each data field is included, but these can be
modified depending upon individual programming and processing requirements.
Data are present for all stars in the catalog, including some which have been
effectively deleted because they are duplicate entries.  These have been
flagged by a "D" in byte 46 and are listed in Table 5, but the records and
data have been left in the machine version in order not to change the star
counts and numerical sequencing, so that stars appear in their correct
locations if the catalog is sorted by declination, so that data can be
retrieved for those stars if the HD numbers have been used elsewhere in the
literature or in other catalogs, and in the event that it is decided at a
later time that a wrong star has been suppressed.  Although there are not many
of these stars, the user should check byte 46 before using the HD numbers or
data in other compilations or in publications, and before using the data to
prepare finding charts, etc.  All data fields having primary A-format
specifications are blank for missing data, so the alternate numerical formats
used for machine searches will produce zero values.  Data are always present
in fields for which primary numerical format specifications are given, except
for magnitude data, where the fields are left blank if no values are present
in the published catalog (see the tabular descriptions for bytes 30-34 and
36-39).  The data file is ordered strictly by HD number, although in certain
cases, stars are now not in right ascension order (see Table 6) because of
corrections made to their equatorial coordinates.


Table 1.  File Contents.  The Henry Draper Catalogue (Machine Version 1985).

                     Suggested
Byte(s)   Units       Format      Description

    1-6    ---         I6         HD number.

    7-8    ---         A2         Durchmusterung (DM) identification (BD, CD,
                                  CP) or the letters "AG" (see below).

      9    ---         A1         Sign of DM zone.

  10-11    ---         A2 (I2)    DM zone.  For AG stars (zones +50 to +59)
                                  not in the BD, bytes 7-8 read "AG" and bytes
                                  10-11 give the lowest declination zone in
                                  the appropriate AG catalog (50 or 55).

  12-16    ---         A5 (I5)    DM or AG number.








                                       2-1

Table 1  (continued)

                     Suggested
Byte(s)   Units       Format     Description

     17    ---         A1        Component identification if there are two or
                                 more HD stars with the same DM number.  For
                                 multiple systems included in the Washington
                                 Catalog of Visual Double Stars (WDS, Worley
                                 1984) the same designations are given.

     18    ---         A1        Lower case letter identification for BD
                                 supplemental stars (Warren and Kress 1980).

  19-20   hours        I2        Right ascension equinox 1900.

  21-23    min         F3.1      R.A.

     24    ---         A1        Sign of declination equinox 1900.

  25-26    deg         I2        Dec.

  27-28   arcmin       I2        Dec.

     29    ---         I1        Photovisual magnitude code:

                                  0  measured value
                                  1  value inferred from m(pg) and spectral
                                     type

  30-34    mag         F5.2      Photovisual magnitude, m(v), except for the
                                 following codes for ficticious magnitudes:

                                  20.0   nebula   (Neb  in published catalog)
                                  30.0   variable (var. in published catalog)
                                  40.0   nova     (Nov. in published catalog)
                                  50.0   cluster  (Cl.  in published catalog)
                                  blank  no value in published catalog

     35    ---         A1        "C" denotes that m(v) is the combined value
                                 for this and the following or preceding entry.

     36    ---         I1        Photographic magnitude code (see byte 29).

  37-41    mag         F5.2      Photographic magnitude, m(pg) (see bytes
                                 30-34)

     42    ---         A1        "C" denotes that m(pg) is a combined value for
                                 this and the following or preceding entry.

  43-45    ---         A3        Spectral type.  Contains upper and lower case
                                 characters as in published catalog.



                                     2-2

Table 1  (concluded)

                     Suggested
Byte(s)   Units       Format     Description

  46-47    ---         A2 (I2)   Photographic intensity of the spectrum esti-
                                 mated by Miss Cannon.  The faintest spectra
                                 which could be classified with certainty were
                                 assigned a value of 1, while the densest are
                                 given as 10.  For stars having two
                                 intensities in the published catalog, only
                                 the first is given in the machine version.

     48    ---         A1        Remarks.  The following codes are used:

                                  D  Entry deleted because it is a duplicate
                                     or does not refer to a real star (see
                                     Table 4)
                                  E  Image is at edge of plate
                                  G  Position and BD number taken directly
                                     from AGK and precessed to 1900
                                  M  Multiple images used.  Only one intensity
                                     is included (both are in the published
                                     catalog, however)
                                  R  There is a remark for this star in the
                                     published catalog
                                  *  Spectral type refers to a cluster, nebula
                                     or nebulous star.  (Occurs in the Magel-
                                     lanic-Cloud fields only.)


























                                      2-3

                       SECTION 3 - FILE CHARACTERISTICS


The information in Table 2 is sufficient for a user to describe the indigenous
characteristics of the machine-readable Henry Draper Catalogue to a computer.
Not included is information easily varied from installation to installation,
such as block size (physical record length), blocking factor (number of logical
records per physical record), total number of blocks, tape density, number of
tracks, and internal coding (EBCDIC, ASCII, etc.). These parameters should
always be transmitted if secondary copies of the catalog are supplied to other
users or installations.


Table 2.  File Characteristics.  The Henry Draper Catalogue (Machine Version
          1985).


NUMBER OF FILES ................................................             1

LOGICAL RECORD LENGTH (BYTES) ..................................            48

RECORD FORMAT ..................................................         Fixed

TOTAL NUMBER OF LOGICAL RECORDS ................................        272150































                                     3-1

      SECTION 4 - REMARKS, MODIFICATIONS, ACKNOWLEDGMENTS AND REFERENCES


The original machine-readable Henry Draper Catalogue was obtained on magnetic
tape from the U. S. Naval Observatory in the mid 1970's.  Although some
corrections were incorporated into the tape version at the ADC in 1976, no
major revision to the format (as described below) had been made prior to this
version.  The changes described here were made to improve the quality of the
machine version and to make the catalog generally easier to use.  This is
especially significant in the case of the AG zones, where no positions are
given in the published version, and in the Magellanic-Cloud regions where only
X and Y rectangular coordinates were reported.

Two sections of The Henry Draper Extension (HDE, Cannon 1924-1936) which
include stars between +50 and +55 degrees and between +55 and +60 degrees (HDE
232101-240500) identify stars only by their AG numbers.  For the stars in the
Yale Zone Catalogues for these zones (Barney et al. 1959), BD numbers and
positions were extracted from those catalogs and the positions precessed to
1900.  For the relatively few stars not in the Yale catalogs, these data were
obtained directly from the Astronomische Gesellschaft Katalog (AGK, Kruger
1890; Rogers 1892).  AG numbers are given only for those stars with no BD
numbers.  For most of the stars in the Magellanic Clouds (HDE 268601-270500)
only X,Y coordinates are given in the HDE.  However, CP numbers are included
for 133 stars.  The CP identifications were used to locate these stars in the
Yale Zone Catalogues for -60 to -70 degrees (Fallon 1983) and -70 to -90
degrees (Lu 1971).  The positions in the latter catalogs were used in a least
squares solution to obtain the transformation from X,Y to equatorial
coordinates.  This transformation was then applied to all stars in this section
of the catalog to obtain the right ascensions and declinations.  (The X,Y
coordinates are not included.)  These modifications effected a uniform format
for the entire catalog, as well as making the AG and MC sections more readily
usable.

All letters which are lower case in the printed version of the HD can be read
as lower case letters here.  Missing data are blank in the corresponding
records, but numerical codes are retained in the magnitude bytes for nebulae,
novae, clusters, and variable stars so that these may continue to be read with
an F format.  Double-star-component identifications were changed to agree with
the component identifications in the Washington Catalog of Visual Double Stars
(WDS, Worley 1984 update of Jeffers et al. 1963 Index Catalogue of Visual
Double Stars); for stars not in the WDS, components were labeled according to
visual magnitude.  For pairs not in the IDS with identical or combined
magnitudes, the designation denoting the western component as "A" was retained.
Supplemental (footnoted) BD stars (Warren and Kress 1980) are denoted by lower
case letters in a byte separate from that used for double-star components.  For
AG stars not included in the BD, the lowest declination for the AG zone and the
AG number are given.  Uncertain spectral types have been designated by a colon
in byte 43 instead of by "Q" as in the previous version.  The DM numbers are
now given in their full representation, including the catalog designation.
This eliminates the difficulty experienced in the printed version for stars not
contained in the proper catalogs for their declinations, as well as the need to
indicate stars which changed declination zones between 1855 or 1875 and 1900.



                                     4-1

The previous machine version contained the serious problem of the HDE stars
231301 to 240500 being shown as having m(pg) data, whereas they are in fact,
unlike the rest of the HDE, m(v) data.  They have therefore been moved to the
m(v) field in the new version.  Plus signs (byte 24) for all positive
declinations have been added in this version.

Errata were checked as thoroughly as possible and appropriate corrections
entered into the catalog.  The positions, magnitudes, and spectral types were
then compared approximately with the values given for each HD star in the
Strasbourg Catalog of Stellar Identifications (CSI, Ochsenbein et al. 1981).
DM numbers were compared with those in both the CSI and the new SAO-HD-GC-DM
Cross Index (Roman et al. 1983).  All discrepancies were checked and
corrections made as necessary.  A version of the HD sorted by DM number was
checked for duplicate entries and component identifications were added as
described above.  This check also uncovered a number of errors, including the
omission of many supplemental BD designations.

Changes to the original machine version of The Henry Draper Catalogue are
listed in Table 4.  The column "S" denotes the source of a change by the
following code:

      1 - Hoffleit 1976
      2 - ADC 1976 (included in a previous machine version; these corrections
          were carefully tabulated and a typed list prepared, but they were
          not published.  Published errata included in the tabulation were
          lists by Jung and Bischoff 1971 and the Hoffleit 1976 list which has
          subsequently been separated to become Source 1.  Some corrections in
          the former lists were further corrected in the latter)
      3 - S. F. McLaughlin, private communication
      4 - ADC 1985 (changes made since 1976)

Notes on changes for individual stars are given in Table 4.  Stars which should
be deleted, together with the number of the duplicate entry which should be
retained, if any, are listed in Table 5.  As a result of changes in the right
ascensions of a few stars, their entries are now out of time order.  These
stars are listed in Table 6.

After the new machine catalog and listing of changes had been prepared, several
additional errors were found.  These errors are given in Table 7; the changes
for HD 45075, 58881 and 61898 were discovered by E. D. Hoffleit in the course
of reviewing this document.  The remaining ones were detected at the ADC while
working on other catalogs.  The errors in Table 7 will be corrected in some
future version of the machine catalog.












                                     4-2

Table 3.  Explanatory Notes to Individual Changes.

   HD    Remarks

 45075   Hoffleit (1976) states that the position given refers to CD-38 2619,
         whereas the spectral type refers to -38 2621.  The positions have been
         changed to those for -38 2621.

 55363   This star is identified as -0 1641 in the HD, but in the second HDE
         (Cannon and Walton Mayall 1949) the star numbered HD 55363, spectral
         type A2, is -0 1642.  W. Stein recommended changing the identification
         in the SAO to -0 1641.  It seems likely that the HD star is the nor-
         thern, slightly fainter star of the pair, or -0 1641.  The SAO star
         may or may not be the HD star.

 61898   Hoffleit (1976) states that the position given refers to CD-36 3788,
         whereas the spectral type refers to -36 3787.  The declination has
         been changed to that for -36 3787.

 89880   The printed catalog lists this star at declination -79 45 with the DM
         number in italics (i.e., referring to the adjacent declination zone).
         The star appears to be CP-78 536 at declination -78 45.

168235   According to Hoffleit (1976), the magnitudes and position correspond
         to CD-32 14019, whereas the spectral type refers to -32 14027.  The
         DM number, magnitudes, and positions have been changed to those for
         -32 14027.




                   Table 5.  Stars Deleted from the Catalog.

                           Delete            Retain

                            62122            206487
                            82990             82967
                            87124             87107
                            91169            109005
                            93428             93470
                           132017            131999
                           164863            164883
                           217507            217490
                           240507            240515
                           240750            240762
                           243090
                           252214             41909
                           266439            266474







                                      4-3

      Table 7.  Additional Errors Still Present in This Machine Version.

                 HD        Item          For            Read

                45075      DEC         -38 16          -38 14

                58881      SPEC          Rp              S

                61898      DEC         -36 52          -36 56

               173607      DM           3510A           3510C

               173608      DM           3510B           3510D

               192604      DM           4031A           4031 a








































                                     4-16

ACKNOWLEDGMENTS

We express our appreciation to Dr. E. Dorrit Hoffleit and Mrs. Margaret Walton
Mayall for their help in clarifying certain aspects of The Henry Draper
Catalogue.  Dr. Hoffleit kindly reviewed a preliminary copy of this document,
made extensive comments and suggestions, pointed out additional errors, and
applied her many years of experience toward passing judgment upon it.



REFERENCES

Barney, I., Hoffleit, D. and Jones, R. B. 1959a, Catalogue of the Positions
  and Proper Motions of 8380 Stars Between Declinations +50 and +55,  reduced
  without applying Proper Motions to the Equinox 1950.0, Trans. Astron. Obs.
  Yale Univ. 26, Part II.

Barney, I., Hoffleit, D. and Jones, R. B. 1959b, Catalogue of the Positions and
  Proper Motions of 8164 Stars Between Declinations +55 and +60, reduced
  without applying Proper Motions to the Equinox 1950.0, Trans. Astron. Obs.
  Yale Univ. 27.

Cannon, A.J. 1925-1936, The Henry Draper Extension, Ann. Astron. Obs. Harvard
  College 100.

Cannon, A. J. and Pickering, E. C. 1918-1924, The Henry Draper Catalogue, Ann.
  Astron. Obs. Harvard College 91-99.

Cannon, A. J. and Walton Mayall, M. 1949, The Henry Draper Extension, The Annie
  J. Cannon Memorial Volume, Ann. Astron. Obs. Harvard College 112.

Fallon, F. W. 1983, Catalogue of the Positions and Proper Motions of Stars
  Between Declinations -60 and -70. Trans. Astron. Obs. Yale Univ. 32,
  Part II.

Gottl[ie]b, D. and Hoffleit, D. 1969, Bull. Amer. Astron. Soc. 1, 373.

Hoffleit, D. 1967, Astron. J. 72, 586.

Hoffleit, D. 1976, Errors in The Henry Draper Catalogue, Bull. Inf. Centre
  Donnees Stellaires No. 10, p. 2.

Hoffleit, D. 1977, Errata to the Errata to The Henry Draper Catalog[ue], Bull.
  Inf. Centre Donnees Stellaires No. 12, p. 44.

Jeffers, H. M., van den Bos, W. H. and Greeby, F. M. 1963, Index Catalogue of
  Visual Double Stars, 1961.0, Pub. Lick Obs. 21.

Jung, J. and Bischoff, M. 1971, Errors Found in the Published Version of the
  H.D. Catalogue, Bull. Inf. Centre Donnees Stellaires No. 2, p. 18 (and
  Addenda by Bischoff in No. 3, p. 23).




                                     4-17

REFERENCES  (concluded)

Kruger, A. 1890, Zonenbeobachtungen der Sterne zwischen 55 and 65 nord.
  Dekl. angestellt an der Sternwarten von Helsingfors und Gotha.  I Band,
  Enhalt d. Zonen 1-338 nebst den mittleren Oertern der Sterne fur 1875
  (Helsingfors:  Kaiserl. Alexanders-Universitat).

Lu, P. K. 1971, Preliminary Catalogue of the Positions and Proper Motions of
  Stars Between Declinations -70 and -90, Trans. Astron. Obs. Yale Univ. 31.

Ochsenbein, F., Bischoff, M. and Egret, D. 1981, Astron. Astrophys. Suppl. 43,
  259.

Rogers, W. A. 1892, Catalogue of 8627 Stars between +49 50 and +55 10  of North
  Declination in 1855.0, Ann. Astron. Obs. Harvard College 15, Part II
  (Cambridge AG).

Roman, N. G., Warren, W. H. Jr. and Schofield, N. J. 1983, Documentation for
  the Machine-Readable Version of the SAO-HD-GC-DM Cross Index (Version 1983)
  NSSDC/WDC-A-R&S 83-17.

Warren, W. H. Jr. and Kress, K. 1980, Astron. Data Center Bull. 1, 19.

Worley, C. E. 1984, Washington Catalog of Visual Double Stars 1984.0 (magnetic
  tape version) (Washington:  U. S. Naval Observatory).






























                                     4-18