J/PAZh/38/776 Complete sample of OB stars within 350pc (Gontcharov, 2012)
Spatial distribution and kinematics of OB Stars.
Gontcharov G.A.
<Pis'ma Astron. Zh. 38, 776 (2012)>
=2012PAZh...38..776G 2012PAZh...38..776G (SIMBAD/NED BibCode)
=2012AstL...38..694G 2012AstL...38..694G
ADC_Keywords: Stars, nearby ; Stellar distribution ; Stars, distances ;
Stars, O ; Stars, B-type
Keywords: Star counts - distribution of stars - Hertzsprung-Russell diagram -
main sequence - early types (O and B) - stellar kinematics -
Galactic solar neighborhood -
open clusters and associations: individual (Gould Belt)
Abstract:
The sample of 37485 suspected OB stars selected by Gontcharov
(2008AstL...34....7G 2008AstL...34....7G) from the Tycho-2 catalogue has been cleaned of
the stars that are not of spectral types OV-A0V. For this purpose, the
apparent magnitude VT from Tycho-2, the absolute magnitude MVT
calibrated as a function of the dereddened color index (BT-VT)0, the
interstellar extinction AVT calculated from the 3D analytical model by
Gontcharov (2009AstL...35..780G 2009AstL...35..780G) as a function of the Galactic
coordinates, and the photometric distance Rph calculated as a function
of VT, MVT, and AVT have been reconciled in an iterative process.
The 20514 stars that passed the iterations have (BT-VT)0<0 and
MVT>-5 and are considered as a sample of OV-A0V stars complete
within 350 pc of the Sun. Based on the theoretical relation between
the dereddened color and age of the stars, the derived sample has been
divided into three subsamples: (BT-VT)0< -0.2,
-0.2<(BT-VT)0< -0.1, and -0.1<(BT-VT)0<0, younger than 100,
100-200, and 200-400 Myr, respectively. The spatial distribution of
all 20514 stars and the kinematics analyzed for more than 1500 stars
with radial velocities from the PCRV and RAVE catalogues are different
for the subsamples, showing smooth rotations, shears, and deformations
of the layer of gas producing stars with the formation of the Gould
Belt, the Great Tunnel, the Local Bubble, and other structures within
the last 200 Myr. The detected temporal variations of the velocity
dispersions, solar motion components, Ogorodnikov-Milne model
parameters, and Oort constants are significant, agree with the results
of other authors, and show that it is meaningless to calculate the
kinematic parameters for samples of stars with uncertain ages or with
a wide range of ages.
Description:
Catalog of 20514 OB stars from Tycho-2 catalogue.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ob2012.dat 94 20514 OB stars from 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)
I/311 : Hipparcos, new Reduction of the Raw data (van Leeuwen, 2007)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
III/252 : Pulkovo radial velocities for 35493 HIP stars (Gontcharov 2006)
Byte-by-byte Description of file: ob2012.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TYC1 TYC1 from TYC (1)
6- 10 I5 --- TYC2 TYC2 from TYC (1)
12- 16 F5.2 mag VTMAG [-4.99,1.32] Absolute magnitude VT (2)
18- 21 I4 pc Dist [17,7486] Photometric distance (3)
23- 27 I5 pc X X rectangular galactic coordinate (4)
29- 33 I5 pc Y Y rectangular galactic coordinate (4)
35- 39 I5 pc Z Z rectangular galactic coordinate (4)
41- 44 F4.2 mag AVe [0.02,1.53] Extinction in the equatorial
layer (5)
46- 49 F4.2 mag AVg [0.00,1.37] Extinction in the Gould belt (5)
51- 54 F4.2 mag AV [0.03,1.74] Total interstellar extinction (5)
56- 60 F5.2 mag (BT-VT)0 [-0.42,0.00] Dereddened (BT-VT) (6)
62- 65 F4.2 mag E(BT-VT) [0.01,0.59] Color Excess E(BT-VT) (7)
67- 69 I3 Myr Age [82,420] Approximate age (8)
71- 76 I6 -- HIP ? HIP (Cat. I/239) number
78- 85 F8.4 deg RAdeg Right ascension in decimal degrees (J2000.0)
87- 94 F8.4 deg DEdeg Declination in decimal degrees (J2000.0)
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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 VT calculated in this paper.
Note (3): Photometric distance calculated in this paper.
Note (4): Rectangular galactic coordinates X to the galactic centre, Y to
the direction of galactic rotation and Z to the northern galactic pole
calculated in this paper.
Note (5): Interstellar extinction AV is the sum of the ones in the equatorial
layer and in the Gould belt calculated from 2012AstL...38...87G 2012AstL...38...87G.
Note (6): Dereddened (BT-VT) calculated in this paper.
Note (7): Color index E(BT-VT) calculated in this paper.
Note (8): Approximate age calculated from Gontcharov, 2012AstL...38..771G 2012AstL...38..771G.
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Acknowledgements:
George Gontcharov, georgegontcharov(at)yahoo.com
(End) George Gontcharov [Pulkovo Obs.], Patricia Vannier [CDS] 05-Jan-2016