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II/104   Photographic UBV Photometry, Open Clusters        (Mermilliod 1984) 
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Photographic UBV Photometry for Stars in Open Clusters
  Mermilliod J.C.
  <CDS Bull. No. 27, p. 141 (1984)>
  =1984BICDS..27..141M
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ADC_Keywords: Clusters, open ; Photometry, UBV

Description:
  This catalog is a compilation of previously published UBV
  photographic photometry of over 34000 stars in 127 open clusters. 
  The author has adopted a uniform numbering system (as used in some
  other catalogs) and translated the identifications of all stars to
  this system.  References to the photometric data and the individual
  numbering systems are also included.  The catalog is in three files:
  the first file lists the catalog data, the second lists the full
  forms of the references cited by code number in the first, and the
  third contains a list of references to the numbering schemes for
  each cluster. 

File Summary:
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 FileName    Lrecl    Records    Explanations
--------------------------------------------------------------------------------
ReadMe          80          .    This file
catalog.dat     32      42575    Catalog data
refs.dat        76        362    References to the catalog data 
nmbsys.dat      78        135    Cluster reference codes and sources 
--------------------------------------------------------------------------------

Byte-by-byte Description of file: catalog.dat
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   Bytes  Format  Units  Label      Explanations
--------------------------------------------------------------------------------
       1   I1     ---    flag      *Catalog flag
   2-  5   I4     ---    Cl_num     Cluster number in the catalog
   6-  9   I4     ---    starNum    Star number in the cluster (translated 
                                     to the standard system where necessary)
      10   A1     ---    Comp       Component number identifying a component of
                                     a multiple system or blank
  11- 16   F6.2   mag    V          ?V magnitudes
  17- 22   F6.2   mag    B-V        ?B-V magnitudes
  23- 28   F6.2   mag    U-B        ?U-B magnitudes
  30- 32   I3     ---    RefCode   *?Reference
--------------------------------------------------------------------------------
Note on flag:
  Single-digit integer flag indicates the catalog in which the cluster is 
  listed:
    2   NGC
    3   IC
    5   Anonymous cluster. There is only one of these in this catalog, Melotte 
        66. The catalog/cluster number for this cluster is 52066.     
Note on RefCode:
  The full forms of the references are listed in the next file.

Byte-by-byte Description of file: refs.dat
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   Bytes  Format  Units  Label     Explanations
--------------------------------------------------------------------------------
   1-  3   I3     ---    RefCode   ?Code number by which the reference is cited
   5- 76   A72    ---    Ref      *Reference
--------------------------------------------------------------------------------
Note on Ref:
  Full form of the reference. When bytes 1-5 are blank, this field is a 
  continuation of the previous record.

Byte-by-byte Description of file: nmbsys.dat
--------------------------------------------------------------------------------
  Bytes  Format	Units  Label     Explanations
--------------------------------------------------------------------------------
     1   I1     ---    flag     *?Catalog flag
  2- 5   I4     ---    Cat       ?Catalog number of the cluster
  6- 9   A4     ---    suffix    any star in cluster placeholder "BBBB"    
 13-78   A66    ---    Ref      *Reference
--------------------------------------------------------------------------------
Note on flag:
  Single-digit integer indicating the catalog in which the cluster is found:
    2  NGC
    3  IC
    5  Anonymous cluster. There is only one of these in this catalog, Melotte 
       66. The catalog/cluster number for this cluster is 52066.
Note on Ref:
  Full form of the reference. When bytes 1-12 are blank, this field is a 
  continuation of the previous record.

Remarks and Modifications:
  The preliminary Catalogue of Photographic UBV Photometry of Stars in Open 
  Clusters (UBVOC) was received by the Astronomical Data Center (ADC), NASA 
  Goddard Space Flight Center, from the Centre de Donnees Astronomiques, 
  Strasbourg (CDS), in July 1985.
  
  The original tape consisted of four text files: the first contained a 
  description of the catalog files, the second contained the main data file, 
  the third listed the references cited by code number in the data file, and 
  the fourth listed references to the cluster numbering systems. The 
  information in the descriptive file has been incorporated into this 
  document. Blank columns were removed from the second file by means of an 
  editor to reduce the record size from 40 to 32 bytes, and the header 
  records in the remaining two files were deleted.
  
  A FORTRAN program was run to check the validity of each field according to 
  its data type and value. In the catalog file, a typographical error was 
  discovered in record 29437 of the catalog file and corrected by referring
  to the source reference. Three data fields in the same file were also 
  found to contain only a decimal point (one V and two B-V). These decimal 
  points were replaced by blanks. Finally, at the suggestion of J.-C. 
  Mermilliod, the cluster designations in the numbering file were slightly 
  reformatted. A "+" preceding each number and a "." separating the catalog 
  number from the remainder of the designation were both deleted so that 
  these number would follow the same format as the identifications in the 
  data file. No other changes have been made to any of the files.
  
  The catalog's original ADC documentation was scanned and included in the 
  ReadMe file. During verification 1 error was found in data file 
  catalog.dat: Record 35298 had a bad decimal point <0> in column 'U-B'. 
  According to the context and the data format (F6.2), the bad data 
  point was changed from 0057 to 0.57.

References to the Documentation:
  Mermilliod J.-C. 1978, CDS Inform. Bull., No. 14, 32
  Mermilliod J.-C. 1979, Astron. Astrophys. Suppl. Ser., 36, 163
  Mermilliod J.-C. 1984, CDS Inform. Bull., No. 27, 141
  Mermilliod J.-C. 1985, unpublished documentation received with the 
    catalog from the CDS
  Mermilliod J.-C. 1987, private communication
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(End)   N.P.M. Kuin and C.-H. Joseph Lyu [Hughes STX/NASA]      07-JUNE-1995