J/A+A/442/229 RR Lyr: kinematics, orbits and z-distribution (Maintz+, 2005)
RR Lyrae stars: kinematics, orbits and z-distribution.
Maintz G., De Boer K.S.
<Astron. Astrophys., 442, 229-237 (2005)>
=2005A&A...442..229M 2005A&A...442..229M
ADC_Keywords: Stars, variable ; Space velocities
Keywords: astrometry - stars: kinematics - stars: variables: RR Lyr -
Galaxy: halo - Galaxy: structure
Abstract:
RR Lyrae stars in the Milky Way are good tracers to study the
kinematic behaviour and spatial distribution of older stellar
populations. A recently established well documented sample of 217
RR Lyr stars with V<12.5mag, for which accurate distances and radial
velocities as well as proper motions from the Hipparcos and Tycho-2
catalogues are available, has been used to reinvestigate these
structural parameters. The kinematic parameters allowed to calculate
the orbits of the stars. Nearly 1/3 of the stars of our sample have
orbits staying near the Milky Way plane.
Description:
The RR Lyrs used for the present investigation are taken from the well
documented sample established by Maintz (2005, Cat. J/A+A/442/381).
For the present investigation we restricted ourselves to those RR Lyrs
from her list which were observed in the Hipparcos mission (see The
Hipparcos and Tycho Catalogues, ESA 1997, Cat. I/239, and the Tycho
2 catalogue, Hog et al. 2000, Cat. I/259).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 89 217 Positions, velocities (given in the Galactic
euclidic system XYZUVW and Θ, Φ) and
orbital data (Ra, Rp, zmax, normalised z-extent,
and eccentricity) of the stars of our sample
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
J/A+A/442/381 : Precise positions of RR Lyrae with Vmax>12.5 (Maintz, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Name of the variable (GCVS)
11- 15 F5.2 kpc X Galactic position X
17- 21 F5.2 kpc Y Galactic position Y
23- 27 F5.2 kpc Z Galactic position Z
29- 34 F6.1 km/s Uvel U velocity
36- 41 F6.1 km/s Vvel V velocity
43- 48 F6.1 km/s Wvel W velocity
50- 55 F6.1 km/s Phi Velocity towards the galactic centre
57- 62 F6.1 km/s Theta Orbital velocity projected to the galactic plane
64- 68 F5.2 kpc Ra Apo-galactic distance
70- 73 F4.2 kpc Rp Peri-galactic distance
75- 79 F5.2 kpc zmax Maximum z-distance reached
81- 84 F4.2 --- nze Normalised z-extent (zmax/R(zmax))
86- 89 F4.2 --- ecc Eccentricity of the orbit
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 28-Jul-2006