J/AJ/121/327 Metal Abundances of Red Clump Stars in NGC6819 (Bragaglia+, 2001)
Metal abundances of red clump stars in open clusters. I. NGC6819.
Bragaglia A., Carretta E., Gratton R.G., Tosi M., Bonanno G., Bruno P.,
Cali A., Claudi R., Cosentino R., Desidera S., Farisato G., Rebeschini M.,
Scuderi S.
<Astron. J., 121, 327-336 (2001)>
=2001AJ....121..327B 2001AJ....121..327B (SIMBAD/NED BibCode)
ADC_Keywords: Spectroscopy ; Equivalent widths ; Stars, fundamental
Keywords:Galaxy: Open Clusters and Associations: Individual: NGC Number:
NGC 6819, Stars: Abundances, Stars: Fundamental Parameters,
Techniques: Spectroscopic
Abstract:
We present an analysis of high-dispersion spectra (R∼40,000) of three
red clump stars in the old open cluster NGC6819. The spectra were
obtained with SARG, the high-dispersion spectrograph of the Telescopio
Nazionale Galileo. The spectra were analyzed using both equivalent
widths measured with an automatic procedure and comparisons with
synthetic spectra. NGC6819 is found to be slightly metal-rich
([Fe/H]=+0.09±0.03, internal error); there are no previous
high-resolution studies to compare. Most element-to-element abundance
ratios are close to solar; we find a slight excess of Si and a
significant Na overabundance. Our spectra can also be used to derive
the interstellar reddening toward the cluster by comparing the
observed colors with those expected from line excitation: we derive
E(B-V)=0.14±0.04, in agreement with the most recent estimate for
this cluster.
Objects:
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RA (2000) DE Designation(s)
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19 41 13.55 +40 12 20.5 NGC 6819 333 (wrong RA in publication)
19 41 14.76 +40 11 00.8 NGC 6819 978
19 41 15.93 +40 11 11.4 NGC 6819 979
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 56 231 Equivalent Widths
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Name Element name and ionization
6- 12 F7.2 0.1nm Wave Wavelength in angstroms
14- 17 F4.2 eV EP Excitation potential of Name
19- 23 F5.2 [-] Log(gf) Log of the oscillator strength
25- 29 F5.1 10-13m EW333 Equivalent width in star 333 in milliAngstroms
31- 34 F4.2 [-] Abd333 Log number abundance of star 333 (1)
36- 40 F5.1 10-13m EW978 Equivalent width in star 978 in milliAngstroms
42- 45 F4.2 [-] Abd978 Log number abundance of star 978 (1)
47- 51 F5.1 10-13m EW979 Equivalent width in star 979 in milliAngstroms
53- 56 F4.2 [-] Abd979 Log number abundance of star 979 (1)
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Note (1): In the scale where log(n(Hydrogen)) = 12.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Laurent Cambresy [CDS] 17-Aug-2004