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II/121   Stellar Distribution Near SA 127, SA 141, SA 189   (Ratnatunga 1983)
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Stellar Distribution Near the Selected Areas 127, 141 and 189
   Ratnatunga K.U.
   <Ph.D. Dissertation, The Australian National University, Canberra (1983)>
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ADC_Keywords: Selected areas ; Stellar distribution

Description:
    Photographic photometry and 1950 coordinates were determined using
    Automated Image location on 50 micron aperture PDS scans of the
    regions on UKSTU Schmidt plates. Galaxy contamination, which is
    small at these relatively bright apparent magnitudes, has not been
    removed from the images located. The image locating algorithm does
    not locate faint stars within 9 seconds of arc of an image of a
    brighter star on the plate. Assuming uniform random distributions,
    the estimated incompleteness is 0.5% at magnitude 15 and 2.2% at
    17.5.

File Summary:
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 FileName    Lrecl    Records    Explanations
--------------------------------------------------------------------------------
ReadMe          80          .    This file
sa127.dat       32      35786    SA 127 field
sa141.dat       32      13612    SA 141 field
sa189.dat       32      31088    SA 189 field
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Byte-by-byte Description of file: sa127.dat, sa141.dat, sa189.dat
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   Bytes  Format  Units   Label     Explanations
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   1-  2   I2     h       RAh       Right Ascension 1950 (hours)
   4-  5   I2     min     RAm       Right Ascension 1950 (minutes)
   7- 10   F4.1   s       RAs      *[0/60] Right Ascension 1950 (seconds) 
      12   A1     ---     DE-       Declination 1950 (sign)
  13- 14   I2     deg     DEd       Declination 1950 (degrees)
  16- 17   I2     arcmin  DEm       Declination 1950 (minutes)
  19- 20   I2     arcsec  DEs      *[0/60] Declination 1950 (seconds) 
  22- 26   F5.2   mag     J         Photographic J magnitude = V + 0.841*(B-V)
  28- 32   F5.2   mag     F         Photographic F magnitude = V - 0.605*(B-V)
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Note on RAs and DEs:
  In numerous records the seconds are equal to 60

Remarks on  Plate Information:
   -----------------------------------------------------------------------------
   J  = IIIa-J KODAK emulsion + 2mm GG395 Schott glass filter  = V + 0.841*(B-V)
   F  = IIIa-F KODAK emulsion + 3mm RG630 Schott glass filter  = V - 0.605*(B-V)
   -----------------------------------------------------------------------------

   ----------------------------------------------------------------------------
   SA  Plate   Observation Air   Exposure  Min Image   Sky    Back    Limiting
       Number     Date     Mass            Diameter   Bright Density  Magnitude
                                 (min)    (microns)  (mag)            (mag)
   ----------------------------------------------------------------------------
   127 J7438S  05-JAN-1982 1.05    15         60       20.5   1.27     19.5
   127 R7407S  20-DEC-1981 1.22    30         85       20.0   0.90     17.7
   141 J7168S  03-JAN-1981 1.00    15         50       21.2   0.44     19.5
   141 R6856S  14-NOV-1980 1.17    12         60       21.3   0.40     17.4
   189 J7227S  30-SEP-1981 1.14    15         35       21.3   0.34     19.5
   189 R7215S  22-SEP-1981 1.16    30         50       20.2   0.74     18.2
   ----------------------------------------------------------------------------

Remarks on Field Information:
    ------------------------------------------------------------
    SA   l   b   Field            RA   (1950)   Dec    No. stars
         d   d  (sq.deg)    h  m     h  m    d      d
    ------------------------------------------------------------
    127 272 +38   20.9     11 00 to 11 20  -20 to -16    35786
    141 245 -86   22.5     01 00 to 01 20  -32 to -37    13612
    189 277 -50   20.9     02 50 to 03 30  -62 to -58    31088
    ------------------------------------------------------------

    Coordinate calibration used positions of SAO stars.

    Estimated rms accuracy for Best Magnitude range 13.5 < V < 16.0:
        Visual magnitude 0.05 mag
        (B-V)  color     0.07 mag
        Positions        1    second of arc

    *** magnitudes brighter than 12 and fainter than 17.5 inaccurate ***

Historical Notes:
    Data format modified at the Astronomical Data Center (ADC)/NASA GSFC,
    1991 October...Wayne H. Warren Jr.
    Data description (prepared at the ADC/NASA GSFC from separate descriptions
    supplied by K. U. Ratnatunga, with format description added,
    1991 November...WHW).

References:    
  Ratnatunga, K.U., and Freeman, K.C. 1985, ApJ, 291, 260
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(End)   C.-H. Lyu [Hughes STX/NASA] and Francois Ochsenbein [CDS]   25-May-1995