J/MNRAS/419/L34 Surface gravity determination in late-type stars (Morel+, 2012)
Assessing the accuracy of the surface gravity determination in late-type stars
with solar-like pulsators.
Morel T., Miglio A.
<Mon. Not. R. Astron. Soc., 419, L34-L38 (2012)>
=2012MNRAS.419L..34M 2012MNRAS.419L..34M
ADC_Keywords: Stars, late-type
Keywords: asteroseismology - stars: fundamental parameters - stars: late-type
Abstract:
The frequency of maximum oscillation power measured in dwarfs and
giants exhibiting solar-like pulsations provides a precise, and
potentially accurate, inference of the stellar surface gravity. An
extensive comparison for about 40 well-studied pulsating stars with
gravities derived using classical methods (ionization balance,
pressure-sensitive spectral features or location with respect to
evolutionary tracks) supports the validity of this technique and
reveals an overall remarkable agreement with mean differences not
exceeding 0.05dex (although with a dispersion of up to ∼0.2dex).
It is argued that interpolation in theoretical isochrones may be the
most precise way of estimating the gravity by traditional means in
nearby dwarfs. Attention is drawn to the usefulness of seismic targets
as benchmarks in the context of large-scale surveys.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables1.dat 93 39 Mean effective temperature, iron content and
mean surface gravities from the four different
methods for the sample stars
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Byte-by-byte Description of file: tables1.dat
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Bytes Format Units Label Explanations
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1 A1 --- lc [ds] Luminosity class: dwarfs (d)
or Subgiants and giants (s)
3- 4 A2 --- --- [HD]
6- 11 I6 --- HD ? HD number
14- 24 A11 --- Name Other name
27- 30 I4 K Teff Effective temperature
32- 34 I3 K e_Teff rms uncertainty on Teff
36- 37 I2 --- o_Teff Number of measurements for Teff
39- 43 F5.2 [Sun] [Fe/H] ? Metallicity
45- 48 F4.2 [Sun] e_[Fe/H] ? rms uncertainty on [Fe/H] (1)
50- 51 I2 --- o_[Fe/H] ? Number of measurements for [Fe/H]
53- 56 F4.2 [cm/s2] logg1 Mean surface gravity for seismic method
58- 61 F4.2 [cm/s2] logg2 ? Mean surface gravity for ionisation method
63- 66 F4.2 [cm/s2] e_logg2 ? rms uncertainty on logg2 (1)
68- 69 I2 --- o_logg2 ? Number of measurements for logg2
71- 74 F4.2 [cm/s2] logg3 ? Mean surface gravity for wings method
76- 79 F4.2 [cm/s2] e_logg3 ? rms uncertainty on logg3 (1)
81 I1 --- o_logg3 ? Number of measurements for logg3
83- 86 F4.2 [cm/s2] logg4 ? Mean surface gravity for isochrone method
88- 91 F4.2 [cm/s2] e_logg4 ? rms uncertainty on logg4 (1)
93 I1 --- o_logg4 ? Number of measurements for logg4
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Note (1): The error bars are the quadratic sum of the standard deviation of the
individual measurements and the typical uncertainty in the parameter
determination (80K for Teff, 0.1dex for [Fe/H], 0.1dex for the ionisation and
isochrone gravities, and 0.15dex for the strong-line gravities).
The typical uncertainty in the seismic logg is 0.03dex (see Section 2).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 01-Jun-2012