J/PAZh/34/21 New spectral types for Tycho2 stars (Tsvetkov+, 2008)
Inaccuracies in the spectral classification of stars from the Tycho-2 Spectral
Type Catalogue.
Tsvetkov A.S., Popov A.V., Smirnov A.A.
<Pis'ma Astron. Zh. 34, 21 (2008)>
=2008PAZh...34...21T 2008PAZh...34...21T
=2008AstL...34...17T 2008AstL...34...17T
ADC_Keywords: Stars, nearby ; Spectral types ; MK spectral classification;
Parallaxes, spectroscopic; Parallaxes, trigonometric ;
Magnitudes, absolute
Keywords: stars - properties - classification - fundamental astronomy -
astrometry - spectral classification - Tycho-2, Hipparcos
Abstract:
We compare the spectroscopic and trigonometric parallaxes of common
stars from the Tycho-2 Spectral Type and Hipparcos Catalogues. This
comparison has revealed that the distance estimations for the
overwhelming majority of stars by both methods yield very similar
results. However, there is a small fraction of stars for which the
distance estimates differences.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 61 Tabulated B-V color indices and absolute magnitudes
M for stars of various spectra and of luminosity
classes I, III and V
table2.dat 57 164 Stars with |δlogr|>1, their corrected
spectral types, and the logarithms of their
distances obtained by the spectroscopic
parallax method
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
III/231 : The Tycho-2 Spectral Type Catalog (Wright+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- SpClass Spectral class
5- 10 F6.3 mag MAG-1 Absolute magnitude for Luminosity class I
13- 18 F6.3 mag (B-V)1 B-V index for Luminosity class I
21- 26 F6.3 mag MAG-3 Absolute magnitude for Luminosity class III
29- 34 F6.3 mag (B-V)3 B-V index for Luminosity class III
37- 42 F6.3 mag MAG-5 Absolute magnitude for Luminosity class V
45- 50 F6.3 mag (B-V)5 B-V index for Luminosity class V
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP HIP (Cat. I/239) number
8- 11 F4.2 [pc] logRt Logarithm of the distance derived from the
trigonometric parallax
13- 17 F5.2 [pc] logRs Logarithm of the distance derived from the
spectroscopic parallax
19- 23 F5.2 mag BT-VT B-V colour index from the Tycho-2 Spectral
Types Catalogue (Cat. III/231)
25- 29 F5.2 mag VTmag Apparent magnitude from the Tycho-2 Spectral
Type Catalogue (Cat. III/231)
31- 36 A6 --- SpType Spectral type from the Tycho-2 Spectral Type
Catalogue (Cat. III/231)
38 A1 --- Type [VHDMCNB] Star type (1)
40- 49 A10 --- SpType1 New (presumed) spectral type
51- 52 A2 --- n_SpType1 [sSlL ] Note on SpType1 (2)
54- 57 F4.2 [pc] logR1 ? Logarithm of the distance calculated from
SpType1
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Note (1): Star type as follows:
V = variable star
H = high-proper-motion star
D = double star
M = multiple star
C = star observed against the background of a cluster
N = carbon star
B = star erroneously identified with Barnard's star
Note (2): Note on new spectral type as follows:
S = spectral type and luminosity class from the SIMBAD database were used
s = only the spectral type from the SIMBAD data base was used
(the luminosity class is unavailable or ignored)
L = luminosity class III was assigned
l = luminosity class V was assigned
sL = combination of the s and L flags
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(End) Veta Avedisova [INASAN], Patricia Vannier [CDS] 09-Apr-2008