J/A+A/597/A52 K and G dwarfs stellar granulation variability (Meunier+, 2017)
Variability of stellar granulation and convective blueshift with spectral
type and magnetic activity.
I. K and G main sequence stars.
Meunier N., Lagrange A.-M., Mbemba Kabuiku L., Alex M., Mignon L.,
Borgniet S.
<Astron. Astrophys. 597, A52 (2017)>
=2017A&A...597A..52M 2017A&A...597A..52M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, K-type ; Stars, G-type ; Magnetic fields ;
Radial velocities
Keywords: convection - stars: magnetic field - stars: activity -
Sun: granulation - techniques: radial velocities
Abstract:
In solar-type stars, the attenuation of convective blueshift by
stellar magnetic activity dominates the RV (radial velocity)
variations over the low amplitude signal induced by low mass planets.
Models of stars that differ from the Sun will require a good knowledge
of the attenuation of the convective blueshift to estimate its impact
on the variations.
It is therefore crucial to precisely determine not only the amplitude
of the convective blueshift for different types of stars, but also the
dependence of this convective blueshift on magnetic activity, as these
are key factors in our model producing the RV.
We studied a sample of main sequence stars with spectral types from G0
to K2 and focused on their temporally averaged properties: the
activity level and a criterion allowing to characterise the amplitude
of the convective blueshift. This criterion is derived from the
dependence of the convective blueshift with the intensity at the
bottom of a large set of selected spectral lines.
Description:
Table 3 lists stars studied in the paper (HARPS data from the ESO
archive), together with informations from various sources and outputs
from our analysis. The number of stars is 167.
Table 4 lists spectral lines used in the papers. It gives their
laboratory wavelength, elements, and number of data sets in which the
line is used. The number of lines is 196.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 60 167 Lists of studied stars
table4.dat 19 196 List spectral lines used
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See also:
J/A+A/487/373 : Spectroscopic parameters of 451 HARPS-GTO stars (Sousa+, 2008)
J/A+A/607/A124 : K-G-F dwarfs stellar granulation variability (Meunier+, 2017)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Star name
12- 13 A2 --- SpType Spectral type from SIMBAD (CDS)
15- 18 F4.2 mag B-V B-V colour index from SIMBAD (CDS)
20- 23 I4 K Teff Effective temperature from
Sousa et al. (2008, Cat. J/A+A/487/373)
25- 29 I5 --- Nsp Number of spectra used in the analysis
31- 37 F7.1 --- TSS Slope of the radial velocity versus line
intensity (1)
39- 43 F5.1 --- e_TSS 1 σ uncertainty on the TSS
45- 50 F6.3 [-] logR'HK Averaged logR'HK index
52- 56 F5.3 [-] e_logR'HK 1 σ uncertainty logR'HK
58- 60 I3 m/s ConvBL Convective blueshift (2)
-------------------------------------------------------------------------------
Note (1): TSS: Slope of the radial velocity versus line intensity, where the
radial velocity and intensity are computed at the bottom of each line,
in m/s/(F/Fc) units. F/Fc represent the relative intensity
(with the continuuml of the spectra normalized to 1)
Note (2): Convective blueshift is derived from the TSS in Section 4.1.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.4 0.1nm Lambda Wavelength (1)
13- 16 A4 --- El Element
19 I1 --- NB Number of data sets in which it is used
-------------------------------------------------------------------------------
Note (1): TiI and FeII wavelengths are from Dravins (2008A&A...492..199D 2008A&A...492..199D),
FeI wavelength are from Nave et al. (1994ApJS...94..221N 1994ApJS...94..221N).
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Acknowledgements:
Nadege Meunier, nadege.meunier(at)univ-grenoble-alpes.fr
References:
Meunier et al., Paper II 2017A&A...607A.124M 2017A&A...607A.124M, Cat. J/A+A/607/A124
(End) Patricia Vannier [CDS] 05-Oct-2016