J/A+A/557/A70 Evolved planet hosts - stellar parameters (Mortier+, 2013)
New and updated stellar parameters for 71 evolved planet hosts.
On the metallicity - giant planet connection.
Mortier A., Santos N.C., Sousa S.G., Adibekyan V.Zh., Delgado Mena E.,
Tsantaki M., Israelian G., Mayor M.
<Astron. Astrophys. 557, A70 (2013)>
=2013A&A...557A..70M 2013A&A...557A..70M
ADC_Keywords: Stars, double and multiple ; Planets ; Abundances, [Fe/H] ;
Effective temperatures ; Stars, masses
Keywords: stars: abundances - stars: fundamental parameters -
techniques: spectroscopic - methods: observational -
methods: statistical
Abstract:
It is still being debated whether the well-known metallicity - giant
planet correlation for dwarf stars is also valid for giant stars. For
this reason, having precise metallicities is very important. Precise
stellar parameters are also crucial to planetary research for several
other reasons. Different methods can provide different results that
lead to discrepancies in the analysis of planet hosts.
To study the impact of different analyses on the metallicity scale for
evolved stars, we compare different iron line lists to use in the
atmospheric parameter derivation of evolved stars. Therefore, we use a
sample of 71 evolved stars with planets. With these new homogeneous
parameters, we revisit the metallicity - giant planet connection for
evolved stars.
A spectroscopic analysis based on Kurucz models in local thermodynamic
equilibrium (LTE) was performed through the MOOG code to derive the
atmospheric parameters. Two different iron line list sets were used,
one built for cool FGK stars in general, and the other for giant FGK
stars. Masses were calculated through isochrone fitting, using the
Padova models. Kolmogorov-Smirnov tests (K-S tests) were then
performed on the metallicity distributions of various different
samples of evolved stars and red giants.
All parameters compare well using a line list set, designed
specifically for cool and solar-like stars to provide more accurate
temperatures. All parameters derived with this line list set are
preferred and are thus adopted for future analysis. We find that
evolved planet hosts are more metal-poor than dwarf stars with giant
planets. However, a bias in giant stellar samples that are searched
for planets is present. Because of a colour cut-off, metal-rich
low-gravity stars are left out of the samples, making it hard to
compare dwarf stars with giant stars. Furthermore, no metallicity
enhancement is found for red giants with planets (logg<3.0dex) with
respect to red giants without planets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 64 71 Parameters from SO08-TS13 line list set (all stars)
(Sousa et al. 2008, Cat. J/A+A/487/373)
table6.dat 64 71 Parameters from HM07 line list (all stars)
(Hekker and Melendez 2007, Cat. J/A+A/475/1003)
tablea1.dat 60 61 Parameters from SO08 line list (cool stars)
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See also:
J/A+A/415/1153 : [Fe/H] for 98 extra-solar planet-host stars (Santos+, 2004)
J/A+A/458/873 : Metal-rich solar-type stars stellar parameters (Sousa+, 2006)
J/A+A/469/783 : Code for automatic determination of EW (ARES) (Sousa+, 2007)
J/A+A/487/373 : Spectroscopic parameters of 451 HARPS-GTO stars (Sousa+, 2008)
J/A+A/475/1003 : Stellar parameters of G and K giant stars (Hekker+, 2007)
J/A+A/512/A47 : 3 stars with giant planets radial velocities (Santos+, 2010)
J/A+A/527/A63 : 7 new HARPS planetary systems RV (Moutou+, 2011)
J/A+A/533/A141 : Stellar parameters for 582 HARPS FGK stars (Sousa+, 2011)
Byte-by-byte Description of file: table5.dat table6.dat tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Star Star name
16- 19 I4 K Teff Effective temperature
21- 23 I3 K e_Teff Error effective temperature
25- 28 F4.2 [cm/s2] logg Surface gravity
30- 33 F4.2 [cm/s2] e_logg Error surface gravity
35- 39 F5.2 [-] [Fe/H] Metallicity
41- 44 F4.2 [-] e_[Fe/H] Error metallicity
46- 49 F4.2 km/s vt Microturbulence ξ
51- 54 F4.2 km/s e_vt Error microturbulence
56- 59 F4.2 Msun Mass ? Stellar mass (not for cool stars, tablea1)
61- 64 F4.2 Msun e_Mass ? Error on stellar mass
(not for cool stars, tablea1)
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Acknowledgements:
Annelies Mortier, amortier(at)astro.up.pt
(End) Annelies Mortier [CAUP-Porto, Portugal], P. Vannier [CDS] 07-Aug-2013