ADC/CDS Standard Document for Catalog:
/catalogs/5/5102/

IMPORTANT NOTICE:

Superseded    SKY2000 - Master Star Catalog, Version 2             (Sande+ 1998)
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SKY2000 - Master Star Catalog - Star Catalog Database, Version 2
    Sande C.B., Warren Jr. W.H., Tracewell D.A., Home A.T., Miller A.C. 
   <Goddard Space Flight Center, Flight Dynamics Division (1998)>
STAR CATALOG DATABASE
SKY2000 MASTER CATALOG  SKYMAP SOFTWARE CAPABILITIES
    Myers J.R., Sande C.B., Miller A.C., Warren Jr. W.H., Tracewell D.A.
   <Goddard Space Flight Center, Flight Dynamics Division (1998)>
    Warren Jr. W.H., Sande C.B., Miller A.C. Myers J.R., Home A.T.,
    Tracewell D.A.
   <Bull. American Astron. Soc., 191, #128.12 (1997)>
   =1997AAS...19112812W
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ADC_Keywords: Positional data; Cross identifications; Combined data; Surveys;

Description:
    The SKYMAP  Star Catalog System  consists of a  Master Catalog stellar
    database  and a collection of utility  software designed to create and
    maintain the database and to generate derivative mission star catalogs
    (run catalogs). It contains an extensive compilation of information on
    almost 300000 stars brighter than 8.0 mag.

Introduction:
    The original SKYMAP Master Catalog was generated in the early 1970's.
    Incremental updates and corrections were made over the following years
    but the first complete revision of the source data occurred with
    Version 4.0. This revision also produced a unique, consolidated source
    of astrometric information which can be used by the astronomical
    community. The derived quantities were removed and wideband and
    photometric data in the R (red) and I (infrared) systems were added.

    This version, SKYMAP SKY2000 Master Catalog, Version 2 of the SKY2000
    Master Catalog was completed in September of 1998 and represents a
    substantial improvement over Version 1 (see catalog <5095>). A high
    proportion of the astrometric data in Version 2 comes from ESA's
    Hipparcos mission, by way of the Hipparcos Output, Hipparcos
    Component, and Tycho Catalogues. Astrometric data are also present
    from USNO's ACT Catalog and the European Tycho Reference Catalogue,
    both of which refine the proper motions in the original Tycho catalog
    by an order of magnitude. While some objects still retain ACRS and PPM
    data, the proportion is very small and there are no stars left in the
    catalog which do not have astrometric quality positions. A large
    number of photoelectric data on the Johnson system (V, B) has been
    added from the Tycho Catalogue, such that there are now very few stars
    in SKY2000 that lack photoelectric data. More than 4000 stars observed
    by the Ball CT-601 star trackers on the RXTE spacecraft now have
    observed CCD ST magnitudes in Version 2. IAU designations based on
    J2000.0 positions have been added to the catalog, while all previous
    identifiers (SKY2000, HD, SAO, DM, HR, WDS, PPM, AG, bright- and
    variable-star designations) have been retained. The IAU-approved
    identifiers allow new objects to be inserted without disrupting the
    natural order of the principal catalog identifier.

    There are some deficiencies that exist in the SKY2000 Master Catalog
    that we are aware of. These items will be researched and corrected in
    future SKY2000 Master Catalog releases. (See file "deficent.txt").

See also:
   Superseded by catalog 5105 in December 2001:
   5105   SKY2000 Catalog, Version 3         (Myers+ 2000)
     at URL ftp://adc.astro.umd.edu/pub/adc/archives/catalogs/5/5105


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