VII/118               NGC 2000.0            (Sky Publishing, ed. Sinnott 1988)
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NGC 2000.0, The Complete New General Catalogue and Index Catalogue
of Nebulae and Star Clusters by J.L.E. Dreyer
     Sinnott, R.W. (edited by)
    <Sky Publishing Corporation and Cambridge University Press (1988)>
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ADC_Keywords: Galaxy catalogs ; Nonstellar objects

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Copyright Notice:
    This catalog is copyrighted by Sky Publishing Corporation, which has
    kindly deposited the machine version in the data centers for permanent
    archiving and dissemination to astronomers for scientific research
    purposes only. The data should not be used for commercial purposes
    without the explicit permission of Sky Publishing Corporation.
================================================================================

Description:
    NGC 2000.0 is a modern compilation of the New General Catalogue of
    Nebulae and Clusters of Stars (NGC), the Index Catalogue (IC), and the
    Second Index Catalogue compiled by J. L. E. Dreyer (1888, 1895, 1908).
    The new compilation of these classical catalogs is intended to meet
    the needs of present-day observers by reporting positions at equinox
    B2000.0 and by incorporating the corrections reported by Dreyer
    himself and by a host of other astronomers who have worked with the
    data and compiled lists of errata. The object types given are those
    known to modern astronomy. The catalog lists object ID, object type,
    positions in equinox B2000.0, source of modern data (see NGC 2000
    paperback copy), constellation, object size, magnitude, and the
    description of the object as given by Dreyer. The order of the new
    catalog is strictly by right ascension, the NGC and IC objects being
    merged into one machine-readable file.

File Summary:
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 FileName    Lrecl    Records    Explanations
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ReadMe          80          .    This file
ngc2000.dat     96      13226    The NGC 2000.0 Catalogue
names.dat       70        227    Index of Messier and common names
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Byte-per-byte Description of file: ngc2000.dat
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   Bytes Format  Units   Label    Explanations
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   1-  5  A5     ---     Name     NGC or IC designation (preceded by I)
   7-  9  A3     ---     Type     Object classification (1)
  11- 12  I2     h       RAh      Right Ascension 2000 (hours)
  14- 17  F4.1   min     RAm      Right Ascension 2000 (minutes)
      20  A1     ---     DE-      Declination 2000 (sign)
  21- 22  I2     deg     DEd      Declination 2000 (degrees)
  24- 25  I2     arcmin  DEm      Declination 2000 (minutes)
      27  A1     ---     Source   Source of entry (2)
  30- 32  A3     ---     Const    Constellation
      33  A1     ---     l_size   [<] Limit on Size
  34- 38  F5.1   arcmin  size     ? Largest dimension
  41- 44  F4.1   mag     mag      ? Integrated magnitude, visual or photographic
                                      (see n_mag)
      45  A1     ---     n_mag    [p] 'p' if mag is photographic (blue)
  47- 96  A50    ---     Desc     Description of the object (3)
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Note (1): the field is coded as follows:
     Gx  = Galaxy
     OC  = Open star cluster
     Gb  = Globular star cluster, usually in the Milky Way Galaxy
     Nb  = Bright emission or reflection nebula
     Pl  = Planetary nebula
     C+N = Cluster associated with nebulosity
     Ast = Asterism or group of a few stars
     Kt  = Knot  or  nebulous  region  in  an  external galaxy
     *** = Triple star
     D*  = Double star
     *   = Single star
     ?   = Uncertain type or may not exist
         = (blank) Unidentified at the place given, or type unknown
     -   = Object called nonexistent in the RNGC (Sulentic and Tifft 1973)
     PD  = Photographic plate defect

Note (2): sources that have been used to correct or update
    modern data in NGC 2000.0 (type, positions, magnitude, and size).
    Uppercase letters denote special NGC and IC errata lists, which have
    usually been accorded more weight than the source catalogues
    themselves. In parentheses after each citation is the number of times
    it has been used to update NGC entries (first number) and those in
    the IC (second number).
    A = Archinal, Brent A. Version 4.0 of an unpublished list of errata to
        the RNGC, dated March 19, 1987. (110,0)
    a = Arp, H., "Atlas of Peculiar Galaxies", 1966ApJS...14....1A (1,2)
        (Catalog <VII/74>)
    c = Corwin, Harold G., Jr., A. de Vaucouleurs, and G. de Vaucouleurs,
        "Southern Galaxy Catalogue", Austin, Texas: University of Texas
        Monographs in Astronomy No. 4, 1985. (152,564)
        (Catalog <VII/116>)
    d = Dreyer, J.L.E., New General Catalogue of Nebulae and Clusters of
        Stars (1888), Index Catalogue (1895), Second Index Catalogue (1908).
        London: Royal Astronomical Society, 1953. (28,2157)
    D = Dreyer, J.L.E., ibid. Errata on pages 237, 281-283, and 366-378.
        (158,28)
    F = Skiff, Brian, private communication of February 27, 1988.  (93,36)
    h = Holmberg, E., "A Study of Double and Multiple Galaxies",
        Lund Annals, 6, 1937. (13,2)
    k = Karachentsev, I.D., "A Catalogue of Isolated Pairs of Galaxies
        in the Northern Hemisphere"; also, Karachentseva, V.E.,
        "A Catalog of Isolated Galaxies." Astrofiz. Issled. Izv. Spetz.
        Astrofiz., 7, 3, 1972, and 8, 3, 1973. (0,4)
        (Catalogs <VII/77>, <VII/82>, <VII/83>)
    m = Vorontsov-Velyaminov, B.A., and V.P. Arhipova,
        "Morphological Catalog of Galaxies", Parts I-V.
        Moscow: Moscow State University, 1962-74. (9,679)
        (Catalogs <VII/62> and <VII/100>)
    n = Reinmuth, K., "Photographische Positionsbestimmung von NebelRecken"
        Veroff der Sternwarte zu Heidelberg, several papers, 1916-40. (0,4)
    o = Alter, G., B. Balazs, and J. Ruprecht, Catalogue of Star Clusters
        and Associations, 2nd edition.  Budapest: Akademiai Kiado, 1970. (5,0)
        (Catalogs <VII/5>, <VII/44> and <VII/101>)
    r = Sulentic, Jack W., and William G. Tifft, "The Revised New General
        Catalogue of Nonstellar Astronomical Objects (RNGC)".
        Tucson, Arizona:University of Arizona Press, 1973. (4016,0)
        (Catalog <VII/1>)
    s = Hirshfeld, Alan, and Roger W. Sinnott, eds., Sky Catalogue 2000.0,
        Vol.2, Cambridge, Massachusetts:
        Sky Publishing Corp. and Cambridge University Press, 1985. (3098,238)
    t = Tully, R.B., "Nearby Galaxies Catalog". New York: Cambridge
        University Press, 1988.
        A preliminary version on magnetic tape (1981) was used here. (23,17)
        (Catalog <VII/145>)
    u = Nilson P.N., Uppsala Ceneral Catalogue of Galaxies.
        Uppsala: Uppsala Astronomical Observatory, 1973. (15,543)
        (Catalog <VII/26>)
    v = de Vaucouleurs, G., A. de Vaucouleurs, and H.C. Corvin, Jr.,
        Second Reference Catalogue of Bright Galaxies. Austin, Texas,
        University of Texas Press, 1976.(118,206)
        (Catalog <VII/112>)
    x = Dixon, R.S., and George Sonneborn, "A Master List of Nonstellar
        Optical Astronomical Objects (MOL)".  Columbus, Ohio,
        Ohio State University Press, 1980.
        It should be noted that most of the information for codes
        a,h,k,m,n,o,u and z was extracted from the magnetic-tape
        version of this catalogue.
        The x code refers to IC objects identified in a literature
        search by these authors. (0,526)
    z = Zwicky, F., E. Herzog, and P. Wild, "Catalogue of Galaxies and
        Clusters of Galaxies", Vol.I. Pasadena, Calif., California Institute
        of Technology, 1961. Also, successive volumes through 1968. (1,380)
        (Catalog <VII/49>)

Note (3): description of the object, as given by Dreyer or
     corrected by him, in a coded or abbreviated form. The abbreviations
     and their combination are fully described in the introduction
     to the published catalog.
     ab       = about
     alm      = almost
     am       = among
     annul    = annular or ring nebula
     att      = attached
     b        = brighter
     bet      = between
     biN      = binuclear
     bn       = brightest to n side
     bs       = brightest to s side
     bp       = brightest to p side
     bf       = brightest to f side
     B        = bright
     c        = considerably
     chev     = chevelure
     co       = coarse, coarsely
     com      = cometic (cometary form)
     comp     = companion
     conn     = connected
     cont     = in contact
     C        = compressed
     Cl       = cluster
     d        = diameter
     def      = defined
     dif      = diffused
     diffic   = difficult
     dist     = distance, or distant
     D        = double
     e        = extremely, excessively
     ee       = most extremely
     er       = easily resolvable
     exc      = excentric
     E        = extended
     f        = following (eastward)
     F        = faint
     g        = gradually
     glob.    = globular
     gr       = group
     i        = irregular
     iF       = irregular figure
     inv      = involved, involving
     l        = little (adv.); long (adj.)
     L        = large
     m        = much
     m        = magnitude
     M        = middle, or in the middle
     n        = north
     neb      = nebula
     nebs     = nebulous
     neby     = nebulosity
     nf       = north following
     np       = north preceding
     ns       = north-south
     nr       = near
     N        = nucleus, or to a nucleus
     p        = preceding (westward)
     pf       = preceding-following
     p        = pretty (adv., before F. B. L, S)
     pg       = pretty gradually
     pm       = pretty much
     ps       = pretty suddenly
     plan     = planetary nebula (same as PN)
     prob     = probably
     P        = poor (sparse) in stars
     PN       = planetary nebula
     r        = resolvable (mottled, not resolved)
     rr       = partially resolved, some stars seen
     rrr      = well resolved, clearly consisting of stars
     R        = round
     RR       = exactly round
     Ri       = rich in stars
     s        = suddenly (abruptly)
     s        = south
     sf       = south following
     sp       = south preceding
     sc       = scattered
     sev      = several
     st       = stars (pl.)
     st 9...  = stars of 9th magnitude and fainter
     st 9..13 = stars of mag. 9 to 13
     stell    = stellar, pointlike
     susp     = suspected
     S        = small in angular size
     S*       = small (faint) star
     trap     = trapezium
     triangle = triangle, forms a triangle with
     triN     = trinuclear
     v        = very
     vv       = _very_
     var      = variable
     *        = a single star
     *10      = a star of 10th magnitude
     *7-8     = star of mag. 7 or 8
     **       = double star (same as D*)
     ***      = triple star
     !        = remarkable
     !!       = very much so
     !!!      = a magnificent or otherwise interesting object
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Byte-by-byte Description of file: names.dat
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   Bytes Format Units   Label     Explanations
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   1- 35  A35   ---     Object    Common name (including Messier numbers)
  37- 41  A5    ---     Name     *NGC or IC name, as in ngc2000.dat
  43- 70  A28   ---     Comment   Text of comment, if any
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Note on Name: this field may be blank for Messier objects without
     NGC or IC counterparts.
     when one object corresponds to several entries in ngc2000,
     the Object is repeated (e.g. Copeland's Septet appears 7 times)
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History by Wayne H. Warren Jr., December 1989:
        It is important, even for users of the machine-readable catalog
    and this documentation, to also have a copy of the published book.
    In addition to the tables and reference sources mentioned in this
    document, the book provides an introductory section with a brief
    history of the NGC and IC catalogs, a count of objects by
    constellation, information on Dreyer's descriptions, a table cross
    index of Messier and NGC/IC designations, and a table of common names
    for NGC objects. The book also contains a table of right ascensions
    for NGC and IC objects.
        A magnetic tape containing NGC 2000.0 was received from
    William E. Shawcross of Sky Publishing Corporation on August 14, 1989.
    According to Mr. Shawcross, the file supplied to the ADC was an
    unmodified version of the one used to produce the book, and it still
    contained the TEX commands employed to produce the special symbols
    present in the printed version. As received, the file also contained a
    single copyright text record at its beginning. The text record was
    removed to an added first file in the archived version and
    supplemented with a small amount of additional information. The TEX in
    the data file was replaced by standard characters to represent the
    information. Special symbols, such as "\Delta", "\bigcirc", etc., were
    changed to their spelled-out equivalents.
        The size field was modified to add decimal points to integer
    numbers and to align all values properly so that the field can be
    processed with a single format specification. The magnitude field was
    modified by moving the "p" code for photographic magnitude to its own
    byte in order to remove it from the numerical field. Decimal points
    were added to all integer numbers in this field also.
        The catalog data file was run through the ADC General
    Verification Program, which checks data ranges and for various other
    problems that can be detected in a systematic way.

Further history:
    The standardised document was generated in April 1977 at CDS
    (James Marcout, Francois Ochsenbein).

Acknowledgements:
    Appreciation is expressed to William E. Shawcross for responding to a
    request from the ADC to make NGC 2000.0 available to the scientific
    community in machine-readable form. Mr. Shawcross also arranged for a
    copy of the machine-readable TEX file to be created for deposit in the
    archives of the data centers. I am grateful to both Mr. Shawcross and
    to Roger W. Sinnott for reviewing a draft copy of this document and
    making comments. The comments resulted in the finding and elimination
    of a few TEX symbols that were missed during the initial work.

    The meticulous documentation initiated by Wayne H. Warren at ADC
    (December 1989) is the basis of the present document.

References:
   Dreyer, J.L.E. 1888, "New General Catalogue of Nebulae and Clusters of
      Stars", MmRAS, 49, Part I (reprinted 1953, London: Royal Astronomical
      Society)
   Dreyer, J.L.E. 1895, "Index Catalogue of Nebulae Found in the Years 1888 to
      1894 with Notes and Corrections to the New General Catalogue", MmRAS, 51,
      185 (London: Royal Astronomical Society, reprinted 1953)
   Dreyer, J.L.E. 1908, "Second Index Catalogue of Nebulae Found in the Years
      1895 to 1907; with Notes and Corrections to the New General Catalogue
      and to the Index Catalogue for 1888 to 1894", MmRAS, 59, Part 2, 105
      (London: Royal Astronomical Society, reprinted 1953)
   Sulentic, J. W. and Tifft, W. G. 1973, "The Revised New General
      Catalogue of Nonstellar Astronomical Objects"
     (Tucson: The University of Arizona Press; catalog <VII/1>).
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(End)                                     Francois Ochsenbein [CDS]  03-Apr-1997