J/A+A/511/38 Open clusters in the Third Galactic Quadrant       (Vazquez+, 2010)
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Open clusters in the Third Galactic Quadrant III. Alleged binary clusters 
       Vazquez R.A., Moitinho A., Carraro G., Dias W.S.
      <Astron. Astrophys. 511, 38 (2010)>
      =2010A&A...511A..38V
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ADC_Keywords: Clusters, open; Photometry, CCD ; Photometry, UBVRI

Keywords: Galaxy: structure - Open clusters and associations: general


Abstract:
    Aims: We aim to determine accurate distances and ages of eight open clusters 
    in order to: (1) assess their possible binarity, (2) provide probes to trace
    the structure of the Third Galactic Quadrant.

    Methods: Cluster reddenings, distances, ages and metallicities are derived 
    from ZAMS and isochrone fits in UBVRI photometric diagrams. Field 
    contamination is reduced by restricting analysis to stars within the cluster
    limits derived from star counts. Further membership control is done by 
    requiring that stars have consistent positions in several diagrams and by 
    using published spectral types.

    Results: The derived distances, ages and metallicities have shown that none 
    of the analysed clusters compose binary/double systems. Of the four 
    candidate pairs, only NGC 2383/NGC 2384 are close to each other, but have 
    different metallicities and ages. Ruprecht 72 and Ruprecht 158 are not 
    clusters but fluctuations of the field stellar density. Haffner 18 is found
    to be the superposition of two stellar groups at different distances: 
    Haffner 18(1) at 4.5 kpc and Haffner 18(2) between 9.5 and 11.4 kpc from 
    the Sun. The derived distances and ages have been used to situate the 
    clusters in the Galactic context. In particular, young stellar groups trace
    spiral structure at large Galactocentric radii. At least two clusters 
    formed during the last few 108 yr in an interstellar medium with less than 
    solar abundances.

    Conclusions: In contrast with the LMC, double clusters are apparently rare,
    or even non existent, in the undisturbed environment of the Third Galactic
    Quadrant. This leaves open the question of whether binary clusters form 
    more easily toward denser and more violent regions of the Milky Way such as
    the inner Galaxy.

File Summary:
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 FileName      Lrecl  Records   Explanations
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ReadMe.txt        80        .   This file
ReadMe            80        .   This file
table1.dat       149     3018   Czernik 29 and Haffner 10 photometric data
table2.dat       155     2304   Haffner 18 and Haffner 19 photometric data
table3.dat       154     2682   NGC 2383 and NGC 2384 photometric data
table4.dat       137     2951   Ruprecht 158 and Ruprecht 72 photometric data
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Byte-by-byte Description of file:table1.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label    Explanations
--------------------------------------------------------------------------------
   7- 10  I4    ---     Ident    Star number (decreasing V magnitude sequential 
                                 order)
  14- 24  F11.7 deg     RAd      Right ascension (J2000.0)
      27  A1    ---     DE-      Declination sign (J2000.0)
  28- 37  F10.7 deg     DEd      Declination (J2000.0)
  42- 47  F6.3  mag     Vmag     V magnitude
  53- 57  F5.3  mag     e_Vmag   Error in V magniute (as given by to DAOPHOT)
  63- 67  F5.3  mag     (B-V)    ?(B-V) colour index
  73- 77  F5.3  mag     e_(B-V)  ? Error in (B-V) colour index (as given by 
                                 DAOPHOT)
      82  A1    ---     (U-B)-   (U-B) colour index sign
  83- 87  F5.3  mag     (U-B)    ?(U-B) colour index
  93- 97  F5.3  mag     e_U-B    ? Error in (U-B) colour index (as given by  
                                 DAOPHOT)
     102  A1    ---     (V-R)-   (V-R) colour index sign
 103-107  F5.3  mag     (V-R)    ?(V-R) colour index
 113-117  F5.3  mag     e_(V-R)  ? Error in (V-R) colour index (as given by 
                                 DAOPHOT)
     122  A1    ---     (V-I)-   (V-R) colour index sign
 123-127  F5.3  mag     (V-I)    ?(V-I) colour index
 133-137  F5.3  mag     e_(V-I)  ? Error in (V-I) colour index (as given by 
                                 DAOPHOT)
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Byte-by-byte Description of file:table2.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label    Explanations
--------------------------------------------------------------------------------
   7- 10  I4    ---     Ident1   Star number (decreasing V magnitude sequential 
                                 order)
  22- 26  A5    ---     Ident2   ? Star number 
                                 (from Fitzgerald & Moffat, 1974AJ.....79..873F)
  31- 41  F11.7 deg     RAd      Right ascension (J2000.0)
      44  A1    ---     DE-      Declination sign (J2000.0)
  45- 54  F10.7 deg     DEd      Declination (J2000.0)
  59- 64  F6.3  mag     Vmag     V magnitude
  70- 74  F5.3  mag     e_Vmag   Error in V magnitude (as given by DAOPHOT)
  80- 84  F5.3  mag     (B-V)    ?(B-V) colour index
  90- 94  F5.3  mag     e_(B-V)  ? Error in (B-V) colour index (as given by 
                                 DAOPHOT)
      99  A1    ---     (U-B)-   (U-B) colour index sign
 100-104  F5.3  mag     (U-B)    ?(U-B) colour index
 110-114  F5.3  mag     e_(U-B)  ? Error in (U-B) colour index (as given by 
                                 DAOPHOT)
     119  A1    ---     (V-R)-   (V-R) colour index sign
 120-124  F5.3  mag     (V-R)    ?(V-R) colour index
 130-134  F5.3  mag     e_(V-R)  ? Error in (V-R) colour index (as given by 
                                 DAOPHOT)
     139  A1    ---     (V-I)-   (V-I) colour index sign
 140-144  F5.3  mag     (V-I)    ?(V-I) colour index
 150-154  F5.3  mag     e_(V-I)  ? Error in (V-I) colour index (as given by 
                                 DAOPHOT)
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Byte-by-byte Description of file:table3.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label    Explanations
--------------------------------------------------------------------------------
   1- 10  I10   ---     Ident1   Star number (decreasing V magnitude sequential 
                                 order)
  12- 15  A4    ---     Ident2   ? Star number 
                                 (from Fitzgerald & Moffat, 1974AJ.....79..873F)
  31- 41  F11.7 deg     RAd      Right ascension (J2000.0)
      44  A1    ---     DE-      Declination sign (J2000.0)
  45- 54  F10.7 deg     DEd      Declination (J2000.0)
  59- 64  F6.3  mag     Vmag     V magnitude
  70- 74  F5.3  mag     e_Vmag   Error in V magniute (as given by DAOPHOT)
  80- 84  F5.3  mag     (B-V)    ?(B-V) colour index
  90- 94  F5.3  mag     e_(B-V)  ? Error in (B-V) colour index (as given by 
                                 DAOPHOT)
      99  A1    ---     (U-B)-   (U-B) colour index sign
 100-104  F5.3  mag     (U-B)    ?(U-B) colour index
 110-114  F5.3  mag     e_(U-B)  ? Error in (U-B) colour index (as given by 
                                 DAOPHOT)
     119  A1    ---     (V-R)-   (V-R) colour index sign
 120-124  F5.3  mag     (V-R)    ?(V-R) colour index
 130-134  F5.3  mag     e_(V-R)  ? Error in (V-R) colour index (as given by 
                                 DAOPHOT)
     139  A1    ---     (V-I)-   (V-I) colour index sign
 140-144  F5.3  mag     (V-I)    ?(V-I) colour index
 150-154  F5.3  mag     e_(V-I)  ? Error in (V-I) colour index (as given by 
                                 DAOPHOT)
--------------------------------------------------------------------------------

Byte-by-byte Description of file:table4.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label    Explanations
--------------------------------------------------------------------------------
   7- 10  I4    ---     Ident    Star number (decreasing V magnitude sequential 
                                 order)
  14- 24  F11.7 deg     RAd      Right ascension (J2000.0)
      27  A1    ---     DE-      Declination sign (J2000.0)
  28- 37  F10.7 deg     DEd      Declination (J2000.0)
  42- 47  F6.3  mag     Vmag     V magnitude
  53- 57  F5.3  mag     e_Vmag   Error in V magniute (as given by DAOPHOT)
  63- 67  F5.3  mag     (B-V)    ?(B-V) colour index
  73- 77  F5.3  mag     e_(B-V)  ? Error in (B-V) colour index
      82  A1    ---     (U-B)-   (U-B) colour index sign
  83- 87  F5.3  mag     (U-B)    ?(U-B) colour index
  93- 97  F5.3  mag     e_U-B    ? Error in (U-B) colour index (as given by 
                                 DAOPHOT)
     102  A1    ---     (V-R)-   (V-R) colour index sign
 103-107  F5.3  mag     (V-R)    ?(V-R) colour index
 113-117  F5.3  mag     e_(V-R)  ? Error in (V-R) colour index (as given by 
                                 DAOPHOT)
     122  A1    ---     (V-I)-   (V-R) colour index sign
 123-127  F5.3  mag     (V-I)    ?(V-I) colour index
 133-137  F5.3  mag     e_(V-I)  ? Error in (V-I) colour index (as given by 
                                 DAOPHOT)
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References:
  Moitinho,        Paper I        2001,A&A...370,..436M
  Moitinho et al., Paper II       2006,A&A...445,..493M, Cat. J/A+A/445/493
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(End)        Ruben A. Vazquez[FCAG-UNLP;IALP-CONICET, Argentina]    26-Nov-2010

