NAME:
  rdstarc
 PURPOSE:
  Read refnet based star catalog files.
 DESCRIPTION:
  Read star catalog file - there are a number of options and consequences
    of running this.  The input file can be either in ASCII tabular format
    or in binary format.  If the file is ASCII you MUST use /NOCONVERT if
    you do not want the input file to be modified.  Otherwise, it will be
    converted to the most appropriate binary format file using starcprmt
    before it is read.

  There are two types of ASCII files.  The old version dating back from the
    USNO catalog days, does not contain any proper motion information.  This
    form of file will naturally map into the v1.0 format file with no loss
    of information.  This file has 10 columns of data of which only the first
    8 are ever examined.  The other two columns were for backward compatibility
    for some long-forgotten software.  These columns are optional and are
    ignored if present.  The 7 columns that are read are:
      col     Contents
      0-2  -- Right ascension (H, M, S)
      3-5  -- Declination (D, M, S).
       6   -- Blue magnitude
       7   -- Red magnitude

  The second type of ASCII file is from Gaia DR1.  It has 11 columns of
    information and is a newly designed format.  During conversion to binary
    form, one of two things can happen.  If you provide EPOCH, the proper
    motion and parallax is applied to the catalog positions and the resulting
    coordinates are saved in the v1.0 binary format.  If you do not provide
    EPOCH, all of the input information is kept and sent back to the user.
    In this latter case, the information comes back in the INFO return
    structure and the formal arguments are populated with the catalog
    information that maps to these arguments but they really aren't of
    much use.  The columns in the file are:
      col     Contents
       0      Right ascension (encoded as a single sexigesimal string, H:M:S)
       1      Declination (encoded as a single sexigemsimal string, D:M:S)
       2      RA proper motion (arcsec/year)
       3      Dec proper motion (arcsec/year)
       4      Parallax (arcsec)
       5      RA uncertainty (arcsec)
       6      Dec uncertainty (arcsec)
       7      RA proper motion uncertainty (arcsec/year)
       8      Dec proper motion uncertainty (arcsec/year)
       9      Parallax uncertainty (arcsec)
      10      G magnitude
    If you use NOCONVERT, you must use the full info structure on return

 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  rdstarc,starfile,ra,dec,bmag,rmag,nstars
 INPUTS:
  starfile - Name of file to read.
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  SILENT - Flag, if set suppresses all non-error output.
  NOCONVERT - Flag, if set, suppresses converting to binary format.
                Only works if the file is not already binary.  If it's
                binary the program dies most unpleasantly.
 OUTPUTS:
  ra   - right ascension in radians (J2000)
  dec  - declination in radians (J2000)
  bmag - Blue magnitude
  rmag - Red magnitude  (see the USNO A2.0 catalog docs to see what this means)
  nstars - Number of stars found (can be zero- in this case other 
          outputs not defined).
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
   There is no version control or fancy validation provided if you bypass
      conversion.  You really should use this only for tiny files where you
      really need to maintain the ASCII version.  This is NOT a normal usage.
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Lowell Observatory, 2002/01/07
  02/03/10 - MWB, added nstars return value
  2007/11/23- Peter L. Collins, Lowell Observatory, 
    convert to v1.0 binary fmt and add promote call.
  2008/10/21, MWB, added SILENT keyword
  2014/03/18, MWB, added NOCONVERT keyword
  2016/11/05, MWB, added support for proper motion and parallax