J/PAZh/37/769 Tycho-2 red giant branch and carbon stars (Gontcharov, 2011)
Red giant branch and carbon stars in the Tycho-2 Catalogue.
Gontcharov G.A.
<Pis'ma Astron. Zh. 37, 769 (2011)>
=2011PAZh...37..769G 2011PAZh...37..769G (SIMBAD/NED BibCode)
=2011AstL...37..707G 2011AstL...37..707G
ADC_Keywords: Proper motions ; Stellar distribution ; Stars, distances ;
Stars, giant
Keywords: Galaxy (Milky Way) - spiral arms - stellar classification -
types of stars - color-magnitude diagram -
open clusters and associations: individual (Gould Belt)
Abstract:
Based on multicolor photometry from the 2MASS and Tycho-2 catalogues,
we have produced a sample of 38368 branch red giants that has less
than 1% of admixtures and is complete within 500 pc of the Sun. The
sample includes 30671 K giants, 7544 M giants,49 C giants, and 104
suspected supergiants or S stars. The photometric distances have been
calculated for K, M, and C stars with an accuracy of 40% together with
reddening and extinction estimates. Tycho-2 proper motions and PCRV
radial velocities are used to analyze the stellar kinematics. The
majority of the selected K and M giants are disk stars with ages of
more than 3Gyr. A small number of K and M giants are extremely young
or, conversely, thick-disk ones. The spatial distribution and
kinematics of the selected C stars force us to consider them as
asymptotic branch giants with masses of more than 2 solar masses and
ages of less than 2Gyr probably associated with the Gould Belt. The
offset of the Sun above the Galactic equator has been found from the
distribution of stars to be 13±2pc, which coincides with the
previously obtained value for the clump red giants.
Description:
Our study showed that the broadband multicolor photometry from the
2MASS and Tycho-2 catalogues is enough to produce a pure (with an
admixture of less than 1%) sample of RGB stars complete within 500pc
of the Sun, to classify the sample stars into types K, M, and C,
suspected supergiants, and S stars, to calculate the interstellar
extinction, and to determine the photometric distances of K, M, and C
stars with an accuracy of 40%.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 106 38368 Branch giants in Tycho-2 catalogue
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
III/231 : The Tycho-2 Spectral Type Catalog (Wright+, 2003)
J/PAZh/34/868 : Red giant clump in the Tycho-2 catalogue (Gontcharov, 2008)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TYC1 TYC1 from Tycho-2 (Cat. I/259) (1)
6- 10 I5 --- TYC2 TYC2 from Tycho-2 (Cat. I/259) (1)
11- 19 F9.4 deg RAdeg Right ascension in decimal degrees (J2000.0)
20- 28 F9.4 deg DEdeg Declination in decimal degrees (J2000.0)
30- 35 I6 --- HIP ? HIP (Cat. I/239) number
36- 44 F9.4 deg GLON Galactic longitude
45- 53 F9.4 deg GLAT Galactic latitude
54- 60 F7.3 mag BTmag [3.790,11.699] Tycho-2 BT magnitude
61- 66 F6.3 mag e_BTmag [0.014,0.158] Error on BTmag
67- 73 F7.3 mag VTmag [2.052,10.477] Tycho-2 VT magnitude
74- 79 F6.3 mag e_VTmag [0.009,0.057] Error on VTmag
80- 86 F7.3 mag VMAG [-1.473,2.890] Absolute magnitude (2)
87- 93 F7.3 mag AVc [-0.402,3.148] Interstellar extinction (2)
94- 98 I5 pc Dist [19,1438] Photometric distance (2)
99-104 F6.3 mag (B-V)0 [1.280,4.196] Dereddened (B-V) (2)
106 A1 --- Class [K,M,I,C] Class (3)
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Note (1): The TYC1 is the GSC region number, TYC2 is the running number
within the region, the TYC component identifier is always 1 for these
stars and is not provided. TYC1 and TYC2 are copied from Tycho-2.
Note (2): Absolute magnitude, interstellar extinction, photometric distance and
dereddened (B-V) are calculated in this paper from photometry for K and M
class and from the 3D extinction model by Gontcharov (2009AstL...35..780G 2009AstL...35..780G)
for C and I class. For I class they can be very uncertain.
Note (3): The stars are separated in this paper into K and M giants, carbon
stars (class C) and I class meaning supergiants and S-stars together.
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Acknowledgements:
George Gontcharov, georgegontcharov(at)yahoo.com
(End) George Gontcharov [Pulkovo Obs.], Patricia Vannier [CDS] 12-Jun-2017