J/A+A/377/123 Equivalent widths of 6 binaries (Gratton+, 2001)
Non-interacting main-sequence binaries with different chemical compositions:
evidences of infall of rocky material?
Gratton R.G., Bonanno G., Claudi R.U., Cosentino R., Desidera S.,
Lucatello S., Scuderi S.
<Astron. Astrophys. 377, 123 (2001)>
=2001A&A...377..123G 2001A&A...377..123G
ADC_Keywords: Stars, double and multiple ; Equivalent widths ; Spectroscopy
Keywords: Planetary systems - Stars: abundances - Binaries: visual
Abstract:
We performed a careful differential abundance analysis of individual
components of six main sequence binaries with separations of a few
hundreds of AU. To reduce analysis concerns, we selected systems with
almost equal mass components. We were able to derive differential
abundances of several elements with errors down to 0.01dex in the
best cases. We found that in four systems the two components have the
same chemical composition, within these very severe limits. However,
clear differences were found for the two remaining systems (HD 219542
and HD 200466), in both cases the primaries being more Fe-rich than the
secondaries, by 0.091±0.009 and 0.053±0.024dex respectively.
Similar differences were found for most of the elements considered in
our analysis; however, we found no appreciable difference for volatile
elements and a trend for increasing abundance differences with
increasing condensation temperature for individual elements, a result
similar to that found for some single stars with planets by Smith et
al. (2001AJ....121.3207S 2001AJ....121.3207S). Finally, we note that HD 219542A has a
Li-abundance comparable to those of Li-rich stars in old open
clusters, while no Li is detected in the slightly cooler HD 219542B. We
suggest that the primaries of these two systems have accreted rocky
planets or the inner dust-rich part of a protoplanetary disk, likely
due to gravitational perturbation caused by the presence of the
companion.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 47 6 Summary of the stars observed
hd008071.dat 37 188 Equivalent widths of HD 008071
hd013357.dat 37 249 Equivalent widths of HD 013357
hd030101.dat 37 208 Equivalent widths of HD 030101
hd033334.dat 37 203 Equivalent widths of HD 033334
hd200466.dat 37 175 Equivalent widths of HD 200466
hd219542.dat 37 228 Equivalent widths of HD 219542
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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) of the primary
8- 12 I5 --- ADS Aitken Double Star number of the binary
14- 25 A12 --- FileName Name of the file with equivalent widths
28- 29 I2 h RAh Right Ascension J2000 (hours)
31- 32 I2 min RAm Right Ascension J2000 (minutes)
34- 37 F4.1 s RAs Right Ascension J2000 (seconds)
39 A1 --- DE- Declination J2000 (sign)
40- 41 I2 deg DEd Declination J2000 (degrees)
43- 44 I2 arcmin DEm Declination J2000 (minutes)
46- 47 I2 arcsec DEs Declination J2000 (seconds)
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Byte-by-byte Description of file: hd*.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ion Element
7- 13 F7.2 0.1nm lambda Wavelength of line
15- 19 F5.2 eV E Potential Energy
21- 25 F5.2 --- logg Log Oscillator Strength
27- 31 F5.1 0.1pm EW(A) Equivalent width of primary (mÅ)
33- 37 F5.1 0.1pm EW(B) Equivalent width of secondary (mÅ)
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Acknowledgements: Raffaele Gratton
(End) Francois Ochsenbein [CDS] 23-Jul-2001