J/AJ/121/2159 Basic parameters for 372 A, F & G stars (Gray+, 2001)
The physical basis of luminosity classification in the late A-, F-, and
early G-type stars.
II. Basic parameters of program stars and the role of microturbulence.
Gray R.O., Graham P.W., Hoyt S.R.
<Astron. J. 121, 2159 (2001)>
=2001AJ....121.2159G 2001AJ....121.2159G
ADC_Keywords: Stars, late-type ; Reddening ; Abundances, [Fe/H] ;
Effective temperatures
Keywords: stars: abundances - stars: atmospheres -
stars: fundamental parameters - stars: late-type -
methods: data analysis - methods: numerical
Abstract:
Paper I (Cat. J/AJ/121/2148) of this series presented precise MK
spectral types for 372 late A-, F-, and early G-type stars with the
aim of understanding the nature of luminosity classification on the MK
spectral classification system for this range of spectral types. In
this paper, a multidimensional downhill simplex technique is
introduced to determine the basic parameters of the program stars from
fits of synthetic spectra and fluxes with observed spectra and fluxes
from Strvmgren uvby photometry. This exercise yields useful
calibrations of the MK spectral classification system but, most
importantly, gives insight into the physical nature of luminosity
classification on the MK spectral classification system. In
particular, we find that in this range of spectral types,
microturbulence appears to be at least as important as gravity in
determining the MK luminosity type.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 232 Basic parameters of late A-, F-, and
early G-Type Stars
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See also:
J/AJ/121/2148 : Precise spectral types for 372 A-G stars (Gray+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD The HD (Cat. III/135) number
8- 11 A4 --- HR The HR (Cat. V/50) designation
13- 26 A14 --- Name Star name
28- 31 F4.2 mag E(b-y) The E(b-y) reddening
33- 36 I4 K Teff The effective temperature
38- 41 F4.2 [cm/s2] log(g) Logarithm of the surface gravity
43- 45 F3.1 km/s xi Microturbulent velocity
47- 51 F5.2 [Sun] [M/H] Metallicity determined by the simplex method
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 19-Jun-2001