J/A+A/426/1007 Abundances of 8 single-lined active binaries (Morel+, 2004)
The photospheric abundances of active binaries.
III. Abundance peculiarities at high activity level.
Morel T., Micela G., Favata F., Katz D., Pillitteri I.
<Astron. Astrophys. 426, 1007 (2004)>
=2004A&A...426.1007M 2004A&A...426.1007M
ADC_Keywords: Stars, variable ; Abundances, peculiar
Keywords: stars: fundamental parameters - stars: abundances -
stars: activity - line: formation
Abstract:
We report the determination from high-resolution spectra of the
atmospheric parameters and abundances of 13 chemical species (among
which lithium) in 8 single-lined active binaries. These data are
combined with our previous results for 6 other RS CVn systems to
examine a possible relationship between the photospheric abundance
patterns and the stellar activity level. The stars analyzed are
generally found to exhibit peculiar abundance ratios compared to
inactive, galactic disk stars of similar metallicities. We argue that
this behaviour is unlikely an artefact of errors in the determination
of the atmospheric parameters or non-standard mixing processes along
the red giant branch, but diagnoses instead the combined action of
various physical processes related to activity. The most promising
candidates are cool spot groups covering a very substantial fraction
of the stellar photosphere or NLTE effects arising from nonthermal
excitation. However, we cannot exclude the possibility that more
general shortcomings in our understanding of K-type stars (e.g.
inadequacies in the atmospheric models) also play a significant role.
Lastly, we call attention to the unreliability of the (V-R) and (V-I)
colour indices as temperature indicators in chromospherically active
stars.
Description:
The spectra were acquired in July 2003 at the ESO 2.2-m telescope (La
Silla, Chile) with the fiber-fed, cross-dispersed echelle spectrograph
FEROS in the object+sky configuration. The atomic data have been
calibrated using a high S/N moonlight spectrum extracted from the
archive of the first FEROS commissioning period (fall 1998).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 65 15 List of the stars studied
tablea1.dat 123 92 Calibrated atomic data and EW measurements
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See also:
J/A+A/412/495 : Equivalent widths for 6 RS CVn systems (Morel+, 2003)
J/A+A/423/677 : Oxygen abundances in chromospherically active stars
(Morel+, 2005)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD number (Cat. III/135)
9- 17 A9 --- Name Other name of the star (1)
20- 21 I2 h RAh Right Ascension J2000 (hours) (1)
23- 24 I2 min RAm Right Ascension J2000 (minutes) (1)
26- 29 F4.1 s RAs Right Ascension J2000 (seconds) (1)
31 A1 --- DE- Declination J2000 (sign) (1)
32- 33 I2 deg DEd Declination J2000 (degrees) (1)
35- 36 I2 arcmin DEm Declination J2000 (minutes) (1)
38- 39 I2 arcsec DEs Declination J2000 (seconds) (1)
42- 46 F5.2 mag Bmag Magnitude in B (1)
48- 52 F5.2 mag Vmag Magnitude in V (1)
54- 64 A11 --- Sp MK Spectral type (1)
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Note (1): data from SIMBAD
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Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ion Ion designation
7- 10 F4.2 [--] SolAbun Kurucz solar abundance
(logarithmic scale, H=12)
12- 19 F8.3 0.1nm Lambda Wavelength
21- 25 F5.3 eV EP Excitation potential
27- 32 F6.3 [--] loggf Calibrated log(gf)-value
34- 38 F5.1 0.1pm EWHD28 ? Equivalent width for HD 28 (1)
40- 44 F5.1 0.1pm EWHD1227 ? Equivalent width for HD 1227 (1)
46- 50 F5.1 0.1pm EWHD4482 ? Equivalent width for HD 4482 (1)
52- 56 F5.1 0.1pm EWHD17006 ? Equivalent width for HD 17006 (1)
58- 62 F5.1 0.1pm EWHD19754 ? Equivalent width for HD 19754 (1)
64- 68 F5.1 0.1pm EWHD154619 ? Equivalent width for HD 154619 (1)
70- 74 F5.1 0.1pm EWHD156266 ? Equivalent width for HD 156266 (1)
76- 80 F5.1 0.1pm EWHD181809 ? Equivalent width for HD 181809 (1)
82- 86 F5.1 0.1pm EWHD182776 ? Equivalent width for HD 182776 (1)
88- 92 F5.1 0.1pm EWHD202134 ? Equivalent width for HD 202134 (1)
94- 98 F5.1 0.1pm EWHD204128 ? Equivalent width for HD 204128 (1)
100-104 F5.1 0.1pm EWHD205249 ? Equivalent width for HD 205249 (1)
106-110 F5.1 0.1pm EWHD211391 ? Equivalent width for HD 211391 (1)
112-116 F5.1 0.1pm EWHD217188 ? Equivalent width for HD 217188 (1)
118-122 F5.1 0.1pm EWHD218527 ? Equivalent width for HD 218527 (1)
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Note (1): A blank indicates that the equivalent width was not reliably
measurable, either because the line was affected by cosmic
rays/telluric features or significantly van der Walls broadened
(see Paper II, Cat. J/A+A/412/495), or because the Gaussian fit
was judged unsatisfactory.
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Acknowledgements: Thierry Morel
(End) Patricia Vannier [CDS] 17-Jun-2004