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J/AJ/142/63         Abundance of five stars in NGC 6397          (Koch+, 2011)
A differential chemical element analysis of the metal-poor globular cluster
NGC 6397.
    Koch A., McWilliam A.
   <Astron. J., 142, 63 (2011)>
   =2011AJ....142...63K
ADC_Keywords: Clusters, globular ; Stars, giant ; Abundances

Keywords: globular clusters: individual (NGC 6397) - stars: abundances -
          stars: atmospheres - stars: individual (Arcturus, Hip 66815)

Abstract:
    We present chemical abundances in three red giants and two turnoff
    (TO) stars in the metal-poor Galactic globular cluster (GC) NGC 6397
    based on spectroscopy obtained with the Magellan Inamori Kyocera
    Echelle high-resolution spectrograph on the Magellan 6.5m Clay
    telescope. Our results are based on a line-by-line differential
    abundance analysis relative to the well-studied red giant Arcturus and
    the Galactic halo field star HIP 66815.

Description:
    Observations were carried out over five nights in 2005 May and June
    using the Magellan Inamori Kyocera Echelle spectrograph at the 6.5m
    Magellan2/Clay telescope.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
stars.dat        100        5   Details of observations, target properties and
                              atmospheric parameters
table2.dat        33      156   Line list for the red giants
table3.dat        29      133   Line list for the turn-off stars


See also:
 J/A+A/287/769  : UV photometry of NGC 6397 (Burgarella+ 1994)
 J/PASP/108/682 : Low-Mass Stars in Outer Field in NGC 6397 (Mould+, 1996)
 J/A+AS/122/1   : BV photometry of variables in NGC 6397 (Kaluzny, 1997)
 J/AJ/119/1225  : Omega Cen and NGC 6397 Stroemgren photometry (Hughes+, 2000)
 J/AJ/120/3111  : Stromgren photometry of NGC 6397 (Anthony-Twarog+, 2000)
 J/A+A/425/509  : VI photometry of NGC 6397 (Andreuzzi+, 2004)
 J/A+A/490/777  : Abundances of Population II stars in NGC 6397 (Lind+, 2008)
 J/AJ/135/2141  : F814W+F606W photometry of NGC 6397 faint stars (Richer+, 2008)
 J/A+A/503/545  : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)
 J/A+A/505/L13  : Lithium in globular NGC 6397 (Gonzalez Hernandez+, 2009)
 J/ApJ/709/241  : NGC 6397 X-rays sources characterisation (Bogdanov+, 2010)


Byte-by-byte Description of file: stars.dat

   Bytes Format Units      Label    Explanations

   1-  5  I5    ---        ID       Star number <Cl* NGC 6397 K NNNNN> in Simbad
   7-  9  A3    ---        Type     Type (RGB or TO=turn-off)
  11- 20  A10 "YYYY/MM/DD" Date     Observation date
  22- 26  I5    s          tExp     Exposure time
  28- 30  I3    pix-1      S/N      Signal-to-noise ratio
  32- 33  I2    h          RAh      Right ascension (J2000)
  35- 36  I2    min        RAm      Right ascension (J2000)
  38- 41  F4.1  s          RAs      Right ascension (J2000)
      43  A1    ---        DE-      Declination sign (J2000)
  44- 45  I2    deg        DEd      Declination (J2000)
  47- 48  I2    arcmin     DEm      Declination (J2000)
  50- 53  F4.1  arcsec     DEs      Declination (J2000)
  55- 59  F5.2  mag        Vmag     V magnitude
  61- 64  F4.2  mag        B-V      B-V colour index
  66- 69  F4.2  mag        V-K      V-K colour index
  71- 74  F4.1  km/s       HV       Heliocentric velocity
  76- 79  I4    K          Teff1    Effective temperature from V-K colour index
  81- 84  I4    K          Teff2    Effective temperature from spectroscopy
  86- 89  I4    K          Teff     Average effective temperature
      90  A1    ---        n_Teff   [a] other indices used for Teff (1)
  92- 95  F4.2  [cm/s2]    logg     Gravity surface
  97-100  F4.2  km/s       Vt       Microturbulent velocity

Note (1): a = Average including Teff (Hα) and the other color indices.



Byte-by-byte Description of file: table2.dat

   Bytes Format Units   Label     Explanations

   1-  5  A5    ---     Ion       Ion designation
   7- 13  F7.2  0.1nm   lambda    Wavelength
  15- 18  F4.2  eV      ExPot     Excitation potential
  20- 23  F4.1  0.1pm   E13414    ? Equivalent width for star #13414 (in mÅ)
  25- 28  F4.1  0.1pm   E8958     ? Equivalent width for star #8958 (in mÅ)
  30- 33  F4.1  0.1pm   E7230     ? Equivalent width for star #7230 (in mÅ)


Byte-by-byte Description of file: table3.dat

   Bytes Format Units   Label     Explanations

   1-  5  A5    ---     Ion       Ion designation
   7- 13  F7.2  0.1nm   lambda    Wavelength
  15- 18  F4.2  eV      ExPot     Excitation potential
  20- 24  F5.1  0.1pm   E13552    ? Equivalent width for star #13552 (in mÅ)
  26- 29  F4.1  0.1pm   E365      ? Equivalent width for star #365 (in mÅ)


History:
    From electronic version of the journal
(End)                  Greg Schwarz [AAS], Patricia Vannier [CDS]    12-Oct-2012