J/A+A/561/A7 High-precision abundances for stars with planets (Ramirez+, 2014)
Chemical signatures of planets: Beyond solar twins.
Ramirez I., Melendez J., Asplund M.
<Astron. Astrophys. 561, A7 (2014)>
=2014A&A...561A...7R 2014A&A...561A...7R
ADC_Keywords: Stars, double and multiple ; Planets ; Abundances ;
Effective temperatures ; Stars, masses ; Stars, ages
Keywords: stars: abundances - stars: fundamental parameters - planetary systems
Abstract:
Elemental abundance studies of solar twin stars suggest that the solar
chemical composition contains signatures of the formation of
terrestrial planets in the solar system, namely small but significant
depletions of the refractory elements. To test this hypothesis, we
study stars which, compared to solar twins, have less massive
convective envelopes (therefore increasing the amplitude of the
predicted effect) or are, arguably, more likely to host planets (thus
increasing the frequency of signature detections). We measure relative
atmospheric parameters and elemental abundances of a late-F type dwarf
sample (52 stars) and a sample of metal-rich solar analogs (59 stars).
We detect refractory-element depletions with amplitudes up to about
0.15dex. The distribution of depletion amplitudes for stars known to
host gas giant planets is not different from that of the rest of
stars. The maximum amplitude of depletion increases with effective
temperature from 5650K to 5950K, while it appears to be constant for
warmer stars (up to 6300K). The depletions observed in solar twin
stars have a maximum amplitude that is very similar to that seen here
for both of our samples. Gas giant planet formation alone cannot
explain the observed distributions of refractory-element depletions,
leaving the formation of rocky material as a more likely explanation
of our observations. More rocky material is necessary to explain the
data of solar twins than metal-rich stars, and less for warm stars.
However, the sizes of the stars' convective envelopes at the time of
planet formation could be regulating these amplitudes. Our results
could be explained if disk lifetimes were shorter in more massive
stars, as independent observations indeed seem to suggest.
Description:
High-precision stellar parameters and chemical abundances are
presented for 111 stars; 52 of them are late-F type dwarfs and 59 are
metal-rich solar analogs. The atomic linelist employed in the
derivation of chemical abundances is also given. This linelist
includes hyperfine structure parameters for some species. The stars'
isochrone masses and ages are also reported, along with estimates of
chromospheric activity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sample.dat 36 111 Sample and literature data
param.dat 63 111 Atmospheric parameters derived in this work
linelist.dat 33 592 Atomic line list including HFS parameters
abund.dat 240 111 Relative elemental abundances
mass_age.dat 42 111 Mass, age, and chromospheric activity data
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See also:
J/A+A/468/663 : Li abundances in solar-analog stars (Takeda+, 2007)
J/A+A/515/A93 : Li abundances in solar-analog stars. II. (Takeda+, 2010)
J/AJ/138/312 : Activity of bright solar analogs (Hall+, 2009)
J/ApJ/720/1592 : Abundances of solar analogs with planets (Hernandez+, 2010)
J/A+A/508/L17 : Abundances in solar analogs (Ramirez+, 2009)
Byte-by-byte Description of file: sample.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos number
8- 10 F3.1 mag Vmag Apparent visual magnitude
12- 15 I4 K Teffl Effective temperature (1)
17- 20 F4.2 [cm/s2] loggl Surface gravity (1)
22- 26 F5.2 [Sun] [Fe/H]l Metallicity (1)
28- 29 I2 --- Nlit Number of sources of atmospheric parameters (1)
31- 36 F6.3 Mjup Mpl ?=- Mass of known planet hosted (2)
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Note (1): The atmospheric parameters listed here correspond to those from our
our literature compilation. Column Nlit shows the number of published values.
Note (2): Minimum mass of known planet hosted or that of the most massive
planet for known multi-planet system hosts.
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Byte-by-byte Description of file: param.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos number
8- 11 I4 K Teff Effective temperature from this work
13- 17 F5.3 [cm/s2] logg Surface gravity from this work
19- 24 F6.3 [Sun] [Fe/H] Metallicity from this work
26- 29 F4.2 km/s vt Microturbulence from this work
31- 34 I4 K dTeff Differential effective temperature (3)
36- 37 I2 K e_dTeff Error on DTeff (3)
39- 44 F6.3 [cm/s2] dlogg Differential surface gravity (3)
46- 50 F5.3 [cm/s2] e_dlogg Error on Dlogg (3)
52- 57 F6.3 [Sun] d[Fe/H] Differential metallicity (3)
59- 63 F5.3 [Sun] e_d[Fe/H] Error on d[Fe/H] (3)
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Note (3): Differential values are given with respect to the standard stars
HIP14954 (warm sample) and HIP74500 (metal-rich solar analogs sample).
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Byte-by-byte Description of file: linelist.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Species Species
7- 10 I4 K Tcond ? Condensation temperature
12- 20 F9.4 0.1nm lambda [4491/8683] Wavelength λ (Å)
22- 26 F5.3 eV EP ? Excitation potential
28- 33 F6.3 --- log(gf) Transition probability
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Byte-by-byte Description of file: abund.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos number
8- 13 F6.3 [-] d[C/H] Differential carbon abundance (4)
15- 19 F5.3 [-] e_d[C/H] Error on d[C/H] (4)
21- 26 F6.3 [-] d[O/H] Differential oxygen abundance (4)
28- 32 F5.3 [-] e_d[O/H] Error on d[O/H] (4)
34- 39 F6.3 [-] d[Na/H] Differential sodium abundance (4)
41- 45 F5.3 [-] e_d[Na/H] Error on d[Na/H] (4)
47- 52 F6.3 [-] d[Mg/H] Differential magnesium abundance (4)
54- 58 F5.3 [-] e_d[Mg/H] Error on d[Mg/H] (4)
60- 65 F6.3 [-] d[Al/H] Differential aluminium abundance (4)
67- 71 F5.3 [-] e_d[Al/H] Error on d[Al/H] (4)
73- 78 F6.3 [-] d[Si/H] Differential silicon abundance (4)
80- 84 F5.3 [-] e_d[Si/H] Error on d[Si/H] (4)
86- 91 F6.3 [-] d[S/H] Differential sulfur abundance (4)
93- 97 F5.3 [-] e_d[S/H] Error on d[S/H] (4)
99-104 F6.3 [-] d[Ca/H] Differential calcium abundance (4)
106-110 F5.3 [-] e_d[Ca/H] Error on d[Ca/H] (4)
112-117 F6.3 [-] d[Sc/H] Differential scandium abundance (4)
119-123 F5.3 [-] e_d[Sc/H] Error on d[Sc/H] (4)
125-130 F6.3 [-] d[Ti/H] Differential titanium abundance (4)
132-136 F5.3 [-] e_d[Ti/H] Error on d[Ti/H] (4)
138-143 F6.3 [-] d[V/H] Differential vanadium abundance (4)
145-149 F5.3 [-] e_d[V/H] Error on d[V/H] (4)
151-156 F6.3 [-] d[Cr/H] Differential chromium abundance (4)
158-162 F5.3 [-] e_d[Cr/H] Error on d[Cr/H] (4)
164-169 F6.3 [-] d[Mn/H] Differential manganese abundance (4)
171-175 F5.3 [-] e_d[Mn/H] Error on d[Mn/H] (4)
177-182 F6.3 [-] d[Co/H] Differential cobalt abundance (4)
184-188 F5.3 [-] e_d[Co/H] Error on d[Co/H] (4)
190-195 F6.3 [-] d[Ni/H] Differential nickel abundance (4)
197-201 F5.3 [-] e_d[Ni/H] Error on d[Ni/H] (4)
203-208 F6.3 [-] d[Cu/H] Differential cupper abundance (4)
210-214 F5.3 [-] e_d[Cu/H] Error on d[Cu/H] (4)
216-221 F6.3 [-] d[Zn/H] Differential zinc abundance (4)
223-227 F5.3 [-] e_d[Zn/H] Error on d[Zn/H] (4)
229-234 F6.3 [-] d[Ba/H] Differential barium abundance (4)
236-240 F5.3 [-] e_d[Ba/H] Error on d[Ba/H] (4)
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Note (4): Differential abundances are given with respect to the standard stars
HIP14954 (warm sample) and HIP74500 (metal-rich solar analogs sample).
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Byte-by-byte Description of file: mass_age.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos number
8- 11 F4.2 Msun Mass Mass of star
13- 16 F4.2 Msun e_Mass 2-σ mass lower limit
18- 21 F4.2 Msun E_Mass 2-σ mass upper limit
23- 26 F4.2 Gyr tau Age τ
28- 31 F4.2 Gyr e_tau 2-σ age lower limit
33- 36 F4.2 Gyr E_tau 2-σ age upper limit
38- 42 F5.2 [-] Act log(R'HK) activity index
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Acknowledgements:
Ivan Ramirez, ivan(at)astro.as.utexas.edu
(End) Ivan Ramirez [Univ. Texas at Austin], Patricia Vannier [CDS] 18-Nov-2013