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J/other/RMxAA/38.129 Stellar Spectral Classification. II. (Stock+, 2002)
Quantitative Stellar Spectral Classification. II. Early Stars. Stock J., Stock M., Garcia J., Sanchez N. <Rev. Mex. Astron. Astrofis., 38, 129 (2002)> =2002RMxAA..38..129S
ADC_Keywords: Stars, early-type ; MK spectral classification ; Magnitudes, absolute ; Equivalent widths Keywords: Stars: Fundamental Parameters Abstract: The method developed by Stock & Stock (1999RMxAA..35..143S) for stars of spectral types A to K to derive absolute magnitudes and intrinsic colors from the equivalent widths of absorption lines in stellar spectra is extended to B-type stars. Spectra of this type of stars for which the Hipparcos catalogue gives parallaxes with an error of less than 20% were observed with the CIDA 1-meter reflector equipped with a Richardson spectrograph with a Thompson 576x384 CCD detector. The dispersion is 1.753Å/pixel using a 600 lines/mm grating in the first order. In order to cover the spectral range 3850Å to 5750Å the grating had to be used in two different positions, with an overlap in the region from 4800Å to 4900Å. A total of 116 stars was observed, but not all with both grating positions. A total of 12 measurable absorption lines were identified in the spectra and their equivalent widths were measured. These were related to the absolute magnitudes derived from the Hipparcos catalogue and to the intrinsic colors (deduced from the MK spectral types) using linear and second order polynomials and two or three lines as independent variables. The best solutions were obtained with polynomials of three lines, reproducing the absolute magnitudes with an average residual of about 0.40 magnitudes and the intrinsic colors with an average residual of 0.016 magnitudes. Description: The following tables contains the 10 best linear and quadratic solutions to calculate the absolute magnitudes and the intrinsic colors, using two or three equivalent widths of some absorption lines. Also, their average residual, the number of used and eliminated stars for each combination are given, as well as the coefficients obtained for the respective terms. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3a.dat 54 10 Linear two-line solutions for the absolute magnitudes using B-spectra table3b.dat 54 10 Linear two-line solutions for the absolute magnitudes using B- and V-spectra table3c.dat 84 10 Quadratic two-line solutions for the absolute magnitudes using B-spectra table3d.dat 84 10 Quadratic two-line solutions for the absolute magnitudes using B- and V-spectra table4a.dat 67 10 Linear three-line solutions for the absolute magnitudes using B-spectra table4b.dat 67 10 Linear three-line solutions for the absolute magnitudes using B-spectra and V-spectra table4c.dat 127 10 Quadratic three-line solutions for the absolute magnitudes using B-spectra table4d.dat 127 10 Quadratic three-line solutions for the absolute magnitudes using B-spectra and V-spectra table6a.dat 54 10 Linear two-line solutions for the intrinsic colors (B-V)0 using B-spectra table6b.dat 54 10 Linear two-line solutions for the intrinsic colors (B-V)0 using B- and V-spectra table6c.dat 84 10 Quadratic two-line solutions for the intrinsic colors (B-V)0 using B-spectra table6d.dat 84 10 Quadratic two-line solutions for the intrinsic colors (B-V)0 using B- and V-spectra table7a.dat 67 10 Linear three-line solutions for the intrinsic colors (B-V)0 using B-spectra table7b.dat 67 10 Linear three-line solutions for the intrinsic colors (B-V)0 using B-spectra and V-spectra table7c.dat 127 10 Quadratic three-line solutions for the intrinsic colors (B-V)0 using B-spectra table7d.dat 127 10 Quadratic three-line solutions for the intrinsic colors (B-V)0 using B-spectra and V-spectra
Byte-by-byte Description of file: table3[ab].dat table6[ab].dat
Bytes Format Units Label Explanations
1- 3 I3 --- L1 Identity of the First line of the combination 4- 6 I3 --- L2 Identity of the Second line of the combination 7- 14 F8.3 mag Rav Average residual of the combination 15- 19 I5 --- Nu Number of used stars for this combination 20- 24 I5 --- Ne Number of eliminated stars for this combination 25- 34 F10.4 --- a00 Coefficient number 1 (1) 35- 44 F10.4 --- a10 Coefficient number 2 (1) 45- 54 F10.4 --- a01 Coefficient number 3 (1)
Note (1): These coefficients are obtained from the polynomial: Mv = a00 + a10*w1 + a01*w2 for tables 3a and 3b (B-V)0 = a00 + a10*w1 + a01*w2 for tables 6a and 6b Where, w1 and w2 are the equivalent widths of the participating lines, and the coefficients aij are listed in the same order in which they appear in the above equation.
Byte-by-byte Description of file: table3[cd].dat table6[cd].dat
Bytes Format Units Label Explanations
1- 3 I3 --- L1 Identity of the First line of the combination 4- 6 I3 --- L2 Identity of the Second line of the combination 7- 14 F8.3 mag Rav Average residual of the combination 15- 19 I5 --- Nu Number of used stars for this combination 20- 24 I5 --- Ne Number of eliminated stars for this combination 25- 34 F10.4 --- a00 Coefficient number 1 (1) 35- 44 F10.4 --- a10 Coefficient number 2 (1) 45- 54 F10.4 --- a01 Coefficient number 3 (1) 55- 64 F10.4 --- a20 Coefficient number 4 (1) 65- 74 F10.4 --- a11 Coefficient number 5 (1) 75- 84 F10.4 --- a02 Coefficient number 6 (1)
Note (1): These coefficients are obtained from the polynomial: Mv = a00 + a10*w1 + a01*w2 + a20*w12 + a11*w1*w2 + a02*w22 for tables 3c and 3d (B-V)0 = a00 + a10*w1 + a01*w2 + a20*w1^2 + a11*w1*w2 + a02*w2^2 for tables 6c and 6d Where, w1 and w2 are the equivalent widths of the participating lines, and the coefficients aij are listed in the same order in which they appear in the above equation.
Byte-by-byte Description of file: table4[ab].dat table7[ab].dat
Bytes Format Units Label Explanations
1- 3 I3 --- L1 Identity of the First line of the combination 4- 6 I3 --- L2 Identity of the Second line of the combination 7- 9 I3 --- L3 Identity of the Third line of the combination 10- 17 F8.3 mag Rav Average residual of the combination 18- 22 I5 --- Nu Number of used stars for this combination 23- 27 I5 --- Ne Number of eliminated stars for this combination 28- 37 F10.4 --- a000 Coefficient number 1 (1) 38- 47 F10.4 --- a100 Coefficient number 2 (1) 48- 57 F10.4 --- a010 Coefficient number 3 (1) 58- 67 F10.4 --- a001 Coefficient number 4 (1)
Note (1): These coefficients are obtained from the polynomial: Mv = a000 + a100*w1 + a010*w2 + a001*w3 for tables 4a and 4b (B-V)0 = a000 + a100*w1 + a010*w2 + a001*w3 for tables 7a and 7b Where, w1, w2 and w3 are the equivalent widths of the participating lines, and the coefficients aijk are listed in the same order in which they appear in the above equation.
Byte-by-byte Description of file: table4[cd].dat table7[cd].dat
Bytes Format Units Label Explanations
1- 3 I3 --- L1 Identity of the First line of the combination 4- 6 I3 --- L2 Identity of the Second line of the combination 7- 9 I3 --- L3 Identity of the Third line of the combination 10- 17 F8.3 mag Rav Average residual of the combination 18- 22 I5 --- Nu Number of used stars for this combination 23- 27 I5 --- Ne Number of eliminated stars for this combination 28- 37 F10.4 --- a000 Coefficient number 1 (1) 38- 47 F10.4 --- a100 Coefficient number 2 (1) 48- 57 F10.4 --- a010 Coefficient number 3 (1) 58- 67 F10.4 --- a001 Coefficient number 4 (1) 68- 77 F10.4 --- a200 Coefficient number 5 (1) 78- 87 F10.4 --- a110 Coefficient number 6 (1) 88- 97 F10.4 --- a101 Coefficient number 7 (1) 98-107 F10.4 --- a020 Coefficient number 8 (1) 108-117 F10.4 --- a011 Coefficient number 9 (1) 118-127 F10.4 --- a002 Coefficient number 10 (1)
Note (1): These coefficients are obtained from the polynomial: Mv = a000 + a100*w1 + a010*w2 + a001*w3 + a200*w12 + a110*w1*w2 + a101*w1*w3 + a020*w22 + a011*w2*w3 + a002*w32 for tables 4c and 4d (B-V)0 = a000 + a100*w1 + a010*w2 + a001*w3 + a200*w12 + a110*w1*w2 + a101*w1*w3 + a020*w22 + a011*w2*w3 + a002*w32 for tables 7c and 7d Where, w1, w2 and w3 are the equivalent widths of the participating lines, and the coefficients aijk are listed in the same order in which they appear in the above equation.
Acknowledgements: Javier Garcia References: Stock & Stock, Paper I 1999RMxAA..35..143S
(End) Patricia Bauer [CDS] 26-Sep-2002
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