J/A+A/440/901       Reddening and metallicity of NGC 6752        (Gratton, 2005)
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Precise reddening and metallicity of NGC 6752 from FLAMES spectra.
    Gratton R.G., Bragaglia A., Carretta E., De Angeli F., Lucatello S.,
    Momany Y., Piotto G., Recio Blanco A.
   <Astron. Astrophys. 440, 901 (2005)>
   =2005A&A...440..901G
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ADC_Keywords: Clusters, globular ; Photometry, UBV ; Abundances ; Reddening ;
              Effective temperatures ; Radial velocities ; Equivalent widths
Keywords: stars: abundances - stars: evolution - stars: Population II -
          Galaxy: globular clusters: general - Galaxy: formation
Abstract:
    Accurate reddenings for Globular Clusters could be obtained by
    comparing the colour-temperature obtained using temperatures from
    reddening-free indicator (H{alpha}), with that given by standard
    colour-temperature calibrations. The large multiplexing opportunity
    offered by FLAMES at VLT2 allowed us to obtain spectra centered on
    H{alpha} at a resolution of R=6000 and 5<S/N<50 for 120 stars near the
    turn-off of NGC 6752 with GIRAFFE from a single 1300 seconds exposure
    on June 24th, 2004.

Description:
    Table 3 contains the relative flux in the bands around H{alpha}
    measured on FLAMES GIRAFFE spectra of about 120 stars near the
    Turn-Off of NGC 6752.
    Table 4 contains V magnitudes, B-V colours, effective temperatures
    (derived from the wings of the H{alpha} lines), and reddenings E(B-V)
    from the same stars.
    Table 7 contains the equivalent widths measured on UVES spectra of
    seven stars at the RGB bump of NGC 6752, used to derive precise metal
    abundances for the cluster.

Objects:
    ----------------------------------------------------------
       RA   (2000)   DE    Designation(s)
    ----------------------------------------------------------
    19 10 51.8 -59 58 55   NGC 6752 = GCl 108 = C 1906-600
    ----------------------------------------------------------

File Summary:
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 FileName  Lrecl  Records   Explanations
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ReadMe        80        .   This file
table3.dat    66      120   S/N ratios, heliocentric radial velocities and
                             normalized fluxes for the target stars
table4.dat    34      120   Temperatures and reddenings
table7.dat    68       65   Equivalent widths from UVES spectra
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See also:
   J/ApJS/99/637 : Equivalent widths for 54 red giants (Norris+ 1995)

Byte-by-byte Description of file: table3.dat
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   Bytes Format Units   Label     Explanations
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   1-  5  I5    ---     Seq       Sequential number of the star
   8-  9  I2    ---     S/N       Signal-to-noise ratio
  12- 16  F5.1  km/s    HRV       Heliocentric radial Velocity
  18- 23  F6.3  ---     Flux3     Normalized flux in band 3, 6547.8-6552.8{AA}
  25- 30  F6.3  ---     Flux4     Normalized flux in band 4, 6552.8-6557.8{AA}
  32- 37  F6.3  ---     Flux5     Normalized flux in band 5, 6557.8-6562.8{AA}
  39- 44  F6.3  ---     Flux6     Normalized flux in band 6, 6562.8-6567.8{AA}
  46- 51  F6.3  ---     Flux7     Normalized flux in band 7, 6567.8-6572.8{AA}
  53- 58  F6.3  ---     Flux8     Normalized flux in band 8, 6572.8-6577.8{AA}
  60- 65  F6.3  ---    <Flux5,6>  Average of fluxes in bands 5 and 6
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Byte-by-byte Description of file: table4.dat
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   Bytes Format Units   Label     Explanations
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   1-  5  I5    ---     Seq       Sequential number of the star
   8- 13  F6.3  mag     Vmag      V magnitude
  16- 20  F5.3  mag     B-V       B-V colour index
  22- 25  I4    K       Teff      Effective Temperature
  28- 33  F6.3  mag     E(B-V)    Reddening
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Byte-by-byte Description of file: table7.dat
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  Bytes Format Units  Label   Explanations
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  1-  4  F4.1  ---    El      Element
  6- 12  F7.2  0.1nm  Lambda  Line Wavelength
 15- 18  F4.2  eV     EP      Excitation Potential
 21- 25  F5.2  ---    loggf   log Oscillator Strength
 27- 31  F5.1  0.1pm  EW25072 ? Equivalent width for star 25072
 33- 37  F5.1  0.1pm  EW26529 ? Equivalent width for star 26529
 39- 43  F5.1  0.1pm  EW30409 ? Equivalent width for star 30409
 45- 49  F5.1  0.1pm  EW30426 ? Equivalent width for star 30426
 51- 55  F5.1  0.1pm  EW34854 ? Equivalent width for star 34854
 57- 61  F5.1  0.1pm  EW37999 ? Equivalent width for star 37999
     63  A1    ---  l_EW39672 Limit flag on EW39672
 64- 68  F5.1  0.1pm  EW39672 ? Equivalent width for star 39672
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Acknowledgements: Raffaele Gratton, gratton(at)pd.astro.it

Remarks: the paper indicates the existence of an accurate astrometry, 
    but it has not been possible to get it from any of the authors.
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(End)                                        Patricia Vannier [CDS]  10-Jun-2005