J/AZh/82/601 Abundances of 4 red giants (Antipova+, 2005)
Analysis of the Na, Mg, Al, and Si Abundances in the Atmospheres of Red Giants
of Different Spectral Subgroups.
Antipova L.I., Boyarchuk A.A., Pakhomov Yu.V., Yushkin M.V.
<Astron. Zh. 82, 601 (2005)>
=2005AZh....82..601A 2005AZh....82..601A
=2005ARep...49..535A 2005ARep...49..535A
ADC_Keywords: Stars, giant; Stars, barium; Spectroscopy; Abundances
Abstract:
We analyze the Na, Mg, Al, and Si abundances in the atmospheres of
more than 40 stars, including red giants of different spectral
subgroups (normal red giants, mild and classical barium stars) and
several supergiants.
All these elements exhibit abundance excesses, with the overabundance
increasing with the star's luminosity. The dependence of the
overabundances for each of these elements on the luminosity (or logg)
is the same for all the spectral subgroups, testifying to a common
origin: they are all products of hydrogen burning in the NeNa and MgAl
cycles that have been dredged up from the stellar interiors to the
outer atmospheric layers by convection that gradually develops during
the star's evolution from the main sequence to the red-giant stage.
The sodium abundances derived for several stars are lower than for
other stars with similar atmospheric parameters. The ages and
kinematic characteristics of these two groups of stars suggest that
they probably belong to different stellar generations.
Objects:
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RA (2000) DE Designation(s) (column)
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01 35 59.0 -15 24 01 HD 9856 = HR 459 (W1)
03 20 20.4 +29 02 54 HD 20644 = HR 999 (W2)
12 05 12.5 +08 43 59 HD 104979 = HR 4608 (W3)
19 18 50.9 +00 20 20 HD 181053 = HR 7321 (W4)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 59 689 The equivalent widths
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- El Element
7- 13 F7.2 0.1nm Lambda Wavelength expressed in Angstroem
17- 20 F4.2 eV EP Excitation potentials of the lower level
23- 27 F5.2 [-] loggf Oscillator strength
31- 35 F5.3 0.1nm W1 ? Equivalent width of HD 9856
39- 43 F5.3 0.1nm W2 ? Equivalent width of HD 20644
47- 51 F5.3 0.1nm W3 ? Equivalent width of HD 104979
55- 59 F5.3 0.1nm W4 ? Equivalent width of HD 181053
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(End) Yury Pakhomov, Veta Avedisova [INASAN] 30-May-2006