Procedure

     STCG01 ( STAR catalog type 1, get star data )

     SUBROUTINE STCG01 ( INDEX,  RA,     DEC,    RASIG,
    .                    DECSIG, CATNUM, SPTYPE, VMAG )

Abstract

     Get data for a single star from a SPICE type 1 star catalog.

Required_Reading

     EK

Keywords

     None.

Declarations

     IMPLICIT NONE

     INTEGER               INDEX
     DOUBLE PRECISION      RA
     DOUBLE PRECISION      DEC
     DOUBLE PRECISION      RASIG
     DOUBLE PRECISION      DECSIG
     INTEGER               CATNUM
     CHARACTER*(*)         SPTYPE
     DOUBLE PRECISION      VMAG

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     INDEX      I   Star index.
     RA         O   Right ascension in radians.
     DEC        O   Declination in radians.
     RASIG      O   Right ascension uncertainty in radians.
     DECSIG     O   Declination uncertainty in radians.
     CATNUM     O   Catalog number.
     SPTYPE     O   Spectral type.
     VMAG       O   Visual magnitude.

Detailed_Input

     INDEX    is the index of the star in the list of stars
              that satisfy the selection criteria specified in
              the last call to STCF01.

Detailed_Output

     RA       is right ascension of the star at the catalog epoch
              in radians relative to the J2000 inertial frame.

     DEC      is declination of the star at the catalog epoch in
              radians relative to the J2000 inertial frame.

     RASIG    is the uncertainty in right ascension of the star at
              the catalog epoch in radians.

     DECSIG   is the uncertainty in declination of the star at
              the catalog epoch in radians.

     CATNUM   is the star number in the catalog.

     SPTYPE   is the star's spectral type. See catalog description
              for more information regarding encoding of spectral
              type values.

     VMAG     is the visual magnitude of the star.

Parameters

     None.

Exceptions

     1)  If fetching of any of output values fails, the error
         SPICE(BADSTARINDEX) is signaled.

     2)  If no star catalog has been loaded, an error is signaled by a
         routine in the call tree of this routine.

     3)  If a star catalog type 1 was not queried by calling STCF01
         before calling this routine, an error is signaled by a routine
         in the call tree of this routine.

Files

     This routine reads the data from SPICE type 1 star catalog file
     loaded into the program by a call to STCL01.

     SPICE type 1 star catalog files MUST contain a single data table.
     It can occupy a single segment or it can spread across multiple
     segments. This table MUST include the following columns:

        column name                data type          units
        ----------------------------------------------------
        RA                   DOUBLE PRECISION        DEGREES
        DEC                  DOUBLE PRECISION        DEGREES
        RA_SIGMA             DOUBLE PRECISION        DEGREES
        DEC_SIGMA            DOUBLE PRECISION        DEGREES
        CATALOG_NUMBER       INTEGER
        SPECTRAL_TYPE        CHARACTER*(4)
        VISUAL_MAGNITUDE     DOUBLE PRECISION

     Nulls are not allowed in any of the columns.
     Other columns can also be present in the table but their data
     will NOT be accessible through STCF01 and STCG01 --
     the interface used to access data in the catalog. Note
     that the names and attributes of these additional columns
     must be identical for all segments containing this table.

Particulars

     This routine is intended to be a part of the user interface to
     the SPICE type 1 star catalog. It allows the caller to retrieve
     data for a single star found by STCF01 using the star's
     index within the search result array. This subroutine MUST
     NOT be called before a search by STCF01 was done.

     Other routines in the SPICE type 1 star catalog access
     family are:

        STCL01  load the catalog file and make its data
                available for search and retrieval.

        STCF01  search through the catalog for all stars within
                a specified RA-DEC rectangle.

Examples

     In the following code fragment, STCG01 is used to retrieve
     position and characteristics for every star within an RA - DEC
     rectangle from a particular SPICE type 1 star catalog.

     C
     C     Load catalog file.
     C
           CALL STCL01 ( CATFN, TABNAM, HANDLE )
     C
     C     Search through the loaded catalog.
     C
           CALL STCF01 ( TABNAM, RAMIN,  RAMAX,
          .              DECMIN, DECMAX, NSTARS )
     C
     C     Retrieve data for every star found.
     C
           DO I = 1, NSTARS

              CALL STCG01 ( I, RA, DEC, RASIG, DECSIG,
          .                 CATNUM, SPTYPE, VMAG )

           END DO

Restrictions

     1)  The catalog file STCG01 reads data from MUST be loaded
         by STCL01 and a search through the catalog MUST be done by
         STCF01 before STCG01 is called.

     2)  No other EK queries can be made between the call to STCF01
         and the call to STCG01.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     B.V. Semenov       (JPL)

Version

    SPICELIB Version 1.1.0, 16-JUN-2021 (JDR)

        Added IMPLICIT NONE statement.

        Updated header to comply with NAIF standard. Corrected argument
        names "RASIG" and "DECSIG" in $Brief_I/O.

        Updated entry #3 in $Exceptions section.

    SPICELIB Version 1.0.0, 15-MAY-1996 (BVS)