II/235         The Photometric Magnitude Difference Catalog       (Worley+ 2001)
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The 2001 US Naval Observatory Double Star CD-ROM. IV. The Photometric 
Magnitude Difference Catalog
   Worley C.E., Mason B.D., Wycoff G.L.
   <Astron. J. 122, 3482 (2001)> 
   =2001AJ....122.3482W
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ADC_Keywords: Stars, double and multiple ; Photometry
Keywords: Stars: Binaries: General, Stars: Binaries: Visual, Catalogs

Description:
    The Photometric Magnitude Difference Catalog is a collection of all double
    star photometric data which does not contain astrometric information and is
    therefore inappropriate for the Washington Double Star Catalog. Magnitude
    difference information can be useful in estimating mass ratios, determining
    photocentric positions which are color dependent, or into investigations of
    variability in close binary systems. Due to uncertainties in bandpass 
    characteristics or variability, no summary line is presented, rather a 
    complete listing of all data. 

Introduction:
   The Photometric Magnitude Difference Catalog (hereafter Delta-M Catalog) was 
   initiated as an internal USNO publication by C.E. Worley and remained as an 
   internal publication for over 20 years. While private copies circulated, this
   is the first open presentation of these accumulated data. No ``WDS-like'' 
   summary line is provided, rather, a complete listing of all photometric data 
   is given. When available, bandpass characteristics and errors are provided, 
   as are other notes (for example, systems not in the WDS are indicated).

File Summary:
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 FileName         Lrecl     Records    Explanations
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ReadMe               80           .    This file
deltam.dat           86       19589    Delta-M Catalog
dm.txt               80         177    Delta-M Catalog Documentation 
table1.txt           80          23    ascii version of Table 1
method.txt           80          26    method key for deltam.dat
refs.dat            338        4191    Reference file
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See also:
    http://ad.usno.navy.mil/wds/dmtext.html : Delta-M Catalog
    maintained at the U.S. Naval Observatory

Byte-by-byte Description of file: deltam.dat
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   Bytes  Format  Units      Label     Explanations
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   1-  2   I2     h          RAh      *Right Ascension 2000 (hours)
   3-  5   I3     0.1min     RAdm     *Right Ascension 2000 (minutes)
       6   A1     ---        DE-      *Declination 2000 (sign)
   7-  8   I2     deg        DEd      *Declination 2000 (degrees)
   9- 10   I2     arcmin     DEm      *Declination 2000 (minutes)
  12- 18   A7     ---        DiscName *Discoverer Code & Number
  19- 23   A5     ---        Comp     *Component Identification
  24- 28   F5.2   mag        DM        Magnitude Difference
  31- 32   I2     ---        NumObs    ?Number of observations used to 
                                        compute DM
  34- 41   A8     ---        RefCode  *Reference Code           
  43       A1     ---        Meth     *Method
  44- 86   A43    ---        Notes    *?Notes
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Note on RAh, RAdm, DE-, DEd, DEm:
   The positions given represent our best estimates of these values. Where
   possible, these are based on the WDS data, with proper motion incorporated. 
Note on DiscName:
   The discoverer, identified by a one-to-three letter code, and the 
   discoverer's number, if assigned. The reference list ("refs.dat")
   should be consulted first to identify individuals. 
Note on Comp:
   Components, when the object has more than two. The WDS 2001 scheme is
   maintained.
Note on RefCode:
   The NewCode from refs.dat file. The first three letters corresponds to the
   WDS discoverer while the next four numbers indicate the date of publication.
Note on Meth:
   The various methods are detailed below. There are a plethora of 
   interferometric techniques which are distinguished due to the familiarity of
   the authors with same. For specifics, consult the appropriate reference
   cited in RefCode.
       A = Adaptive Optics.
       B = Long-baseline interferometer visibility amplitude fitting.
       C = Visual measures with a double-image micrometer.
       D = speckle interferometric comparison of DVA peak heights of stars with
           known delta-m and approximately the same brightness.
       E = speckle interferometric visibility curve-fitting.
       F = speckle interferometric fork.
       G = Visual estimate made with an objective grating.
       H = Wickes and Dicke interferometer - rotating prism and high-frequency 
           chopping wheel.
       I = Integrated image taken with speckle camera. No autocorrelation is 
           done, and the scaled peak heights are compared.
       J = CCD.
       K = Focal-grating photometer.
       L = speckle interferometric relative intensity of autocorrelation.
       M = IR speckle interferometric shift-and-add.
       N = Photocell with diaphragm in focal plane.
       O = Lunar Occultation.
       P = Photographic plates.
       Q = Tycho photometry of Hipparcos Stars
       R = Area scanner.
       S = speckle interferometric modified shift-and-add.
       T = speckle interferometric triple correlation or bispectrum.
       V = Photoelectric photometry.
       W = Wedge photometer.
       Z = Visual photometry with a double-image or polarizing photometer.
Note on Notes:
   This may contain specifics of the filter used (both effective wavelength and
   FWHM in nanometers), errors (i.e., ``SIGMA = ''), colors, and indications of
   uncertainty, variability when a component is not in the WDS, or when a
   reference is to an additional publication.
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Byte-by-byte Description of file: refs.dat
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   Bytes   Format   Units     Label     Explanations
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   1-  8    A8      ---       NewCode  *New reference code used in Orbit, 
                                        Speckle and Delta-M Catalogs
  11- 13    A3      ---       OldCode   Discoverer Code
  14- 15    I2      ---       RefNo    *?Reference number of publication
  18- 54    A37     ---       Obs       Observer(s)
  55-338    A284    ---       Publ      Publication reference for measures
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Note on NewCode:
   The first three letters corresponds to the WDS discoverer while the next four
   numbers indicate the date of publication.  New Code = XYZ1999x
Note on RefNo:
   99 = Unpublished, manuscript or reference not found. 

References:
    "Binary star speckle photometry. I - The colors and spectral types of 
    the Capella stars", Bagnuolo, William G., Jr. and Sowell, James R. 1988,
    AJ, 96, 1056 =1988AJ.....96.1056B

    "Second catalogue d'orbites d'Etoiles Doubles visuelles", Baize, P. 1950, 
    Journal des Observateurs, 33, 1 =1950JO.....33....1B
 
    "Differential Binary Star Photometry Using the Adaptive Optics System at 
    Starfire Optical Range", Brummelaar, T. A. Ten, Mason, B. D., Bagnuolo, 
    W. G., Jr., Hartkopf, W. I., McAlister, H. A., and Turner, N. H. 1996, 
    AJ, 112, 1180 =1996AJ....112.1180B
  
    "Binary Star Differential Photometry Using the Adaptive Optics System at 
    Mount Wilson Observatory", ten Brummelaar, Theo, Mason, Brian D., 
    McAlister, Harold A., Roberts, Lewis C., Jr., Turner, Nils H., Hartkopf,
    William I., and Bagnuolo, William G., Jr. 2000, AJ, 119, 2403 
    =2000AJ....119.2403T
 
    "The HIPPARCOS and TYCHO catalogues. Astrometric and photometric star 
    catalogues derived from the ESA HIPPARCOS Space Astrometry Mission", 
    Perryman, M. A. C. and ESA 1997, The Hipparcos and Tycho catalogues. 
    Astrometric and photometric star catalogues derived from the ESA Hipparcos 
    Space Astrometry Mission, Publisher: Noordwijk, Netherlands: ESA 
    Publications Division, 1997, Series: ESA SP Series vol no: 1200, ISBN: 
    9290923997 (set)=1997hity.book.....P 
 
    "Two-colour photometry for 9473 components of close Hipparcos double and 
    multiple stars", Fabricius, C. and Makarov, V. V. 2000, A&A, 356, 141 
    =2000A&A...356..141F
   
    "A photoelectric area scanner for astrometry and photometry of visual 
    double stars", Franz, O. G. 1970, Lowell Observatory Bulletin, 7, 191 
    =1970LowOB...7..191F 
 
    "Relative photographic positions and magnitude difference of the components 
    of Sirius.", Lindenblad, I. W. 1970, AJ, 75, 841 =1970AJ.....75..841L 

    "ICCD Speckle Observations of Binary Stars.XV.An Investigation of Lunar 
    Occultation Systems", Mason, Brian D. 1996, AJ, 112, 2260 
    =1996AJ....112.2260M 

    "Binary Star Orbits from Speckle Interferometry. XI. Orbits of Twelve Lunar
    Occultation Systems.", Mason, Brian D. 1997, AJ, 114, 808
    =1997AJ....114..808M 

    "CD speckle observations of binary stars. VII - A duplicity survey of the 
    Hyades cluster", Mason, Brian D., McAlister, Harold A., Hartkopf, William 
    I., and Bagnuolo, William G., Jr. 1993, AJ, 105, 220 =1993AJ....105..220M
 
    "Photometric Observations. Part I. Chapter IV. Bright Double Stars", 
    Pickering, Edward C., Searle, Arthur, and Upton, Winslow 1879, Annals of 
    Harvard College Observatory, 11, 105 =1879AnHar..11..105P 
   
    "Three Methods of Determining Magnitudes of Individual Stars in Resolved 
    Binary Systems", Roberts, Lewis C., Jr. 1999, PASP, 111, 650 
    =1999PASP..111..650R 
     
    Strand, K.A. 1969, Pub. USNO 18, Pt. 5

    "CCD observations of visual binary stars.", Tokovinin, A. A. and Shatskii, 
    N. I. 1995, Pis ma Astronomicheskii Zhurnal, 21, 523 =1995PAZh...21..523T 

    "Photometric determinations of magnitude differences for visual binaries.", 
    Worley, C. E. 1969, AJ, 74, 764 =1969AJ.....74..764W    
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(End)        B.D.  Mason          [U.S. Naval Observatory]           12-Jul-2002
