J/A+A/381/446 Astrometric Radial Velocities. III. (Madsen+, 2002)
Astrometric Radial Velocities.
III. Hipparcos Measurements of nearby star clusters and associations.
Madsen S., Dravins D., Lindegren L.
<Astron. Astrophys. 381, 446 (2002)>
=2002A&A...381..446M 2002A&A...381..446M
ADC_Keywords: Associations, stellar ; Clusters, open ; Radial velocities ;
Velocity dispersion ; Parallaxes, spectroscopic
Keywords: methods: data analysis - techniques: radial velocities - astrometry -
stars: distances - stars: kinematics -
open clusters and associations: general
Description:
Astrometrically determined kinematic data are given for nearby
clusters and associations, including astrometric radial velocities and
kinematically improved parallaxes for individual stars. The
astrometric radial velocities are determined independent of
spectroscopy.
Table 1 gives the space velocities and internal velocity dispersions
of the clusters and associations. The electronic Table1 (Table1.dat)
is an extended version of Table 1 in the journal paper, now including
the full covariances of the space velocity components as well as the
space motion in spherical coordinates.
Table 2 gives the astrometric radial velocities and kinematically
improved parallaxes for the individual stars. The electronic Table 2
is an extended version of Table 2 in the journal paper, now including
all clusters and associations studied; results using data from both
the Hipparcos and Tycho-2catalogues, as well as the standard errors
for all deduced quantities. The electronic Table 2 is divided into 10
sub-tables (table1a.dat through table2j.dat), one for each cluster or
association.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 204 11 Kinematic data for 11 clusters and associations
table2a.dat 68 77 77 stars in the Ursa Major cluster
table2b.dat 68 179 179 stars in the Hyades cluster
table2c.dat 68 40 40 stars in the Coma Berenices cluster
table2d.dat 68 60 60 stars in the Pleiades cluster
table2e.dat 68 24 24 stars in the Praesepe cluster
table2f.dat 68 179 179 stars in the Lower Centaurus Crux association
table2g.dat 68 218 218 stars in the Upper Centaurus Lupus association
table2h.dat 68 120 120 stars in the Upper Scorpius association
table2i.dat 68 78 78 stars in the Alpha Persei association
table2j.dat 68 59 59 stars in the 'HIP 98321' association
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- t2 [a-j] indicates which table2 lists the stars
3- 23 A21 --- Name *Name of cluster or association
25- 27 I3 --- Nacc Number of stars accepted in the solution
29- 31 I3 --- Nrej Number of stars rejected in the solution
33- 38 F6.2 km/s v0x *Space velocity component on equatorial X axis
40- 44 F5.2 km/s e_v0x *Standard error in v0x
46- 51 F6.2 km/s v0y *Space velocity component on equatorial Y axis
53- 57 F5.2 km/s e_v0y *Standard error in v0y
59- 64 F6.2 km/s v0z *Space velocity component on equatorial Z axis
66- 70 F5.2 km/s e_v0z *Standard error in v0z
72- 75 F4.2 km/s sigv *Internal velocity dispersion
77- 80 F4.2 km/s e_sigv *Standard error of sigv
82- 86 F5.1 deg RA0deg *Right ascension (J2000) of cluster centroid
88- 92 F5.1 deg DE0deg *Declination (J2000) of cluster centroid
94- 99 F6.2 km/s v0r *Astrometric radial velocity of centroid
101-105 F5.2 km/s e_v0r *Standard error of v0r
107-115 F9.4 km2/s2 cxx *Covariance of (v0x,v0x)
117-125 F9.4 km2/s2 cxy *Covariance of (v0x,v0y)
127-135 F9.4 km2/s2 cxz *Covariance of (v0x,v0z)
137-145 F9.4 km2/s2 cyy *Covariance of (v0y,v0y)
147-155 F9.4 km2/s2 cyz *Covariance of (v0y,v0z)
157-165 F9.4 km2/s2 czz *Covariance of (v0z,v0z)
167-172 F6.2 deg RAcdeg *Right ascension (J2000) of convergence point
174-178 F5.2 deg e_RAcdeg *Standard error of RAc, times cos(DEc)
180-185 F6.2 deg DEcdeg *Declination (J2000) of convergence point
187-191 F5.2 deg e_DEcdeg *Standard error of DEc
193-198 F6.2 km/s v0 *Total space velocity
200-204 F5.2 km/s e_v0 *Standard error of v0
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Note on Name:
Name of the cluster or association, as it is referred to in the journal
paper. The association Scorpius OB2 is the union of the (sub-) associations
Lower Centaurus Crux, Upper Centaurus Lupus, and Upper Scorpius. Its entry
refers to a solution in which the whole complex is considered as a single
association with common space velocity.
Note on v0x, v0y, v0z:
Equatorial (ICRS) components of the space velocity of the cluster centroid,
relative the Solar System barycentre, as obtained in the maximum-likelihood
solution using the Nacc stars for which there is a Hipparcos solution in
Table 2.
Note on e_v0x, e_v0y, e_v0z:
Formal standard errors of the space velocity components, as estimated from
the maximum-likelihood solution. Apart from rounding errors, these values
equal the square roots of cxx, cyy and czz, respectively.
Note on sigv, e_sigv:
The estimated internal velocity dispersion of the cluster, and its
estimated standard error. sigv refers to the standard deviation of each
rectangular component of the (assumed isotropic) dispersion. The dispersion
and its standard error were estimated as described in Appendix A.4 of
Paper II (Lindegren et al., 2000A&A...356.1119L 2000A&A...356.1119L)
Note on RA0deg, DE0deg:
Equatorial coordinates of the adopted cluster centroid. These were obtained
from the unweighted mean rectangular coordinates of the Nacc accepted stars
in the cluster. The adopted coordinates were obtained by rounding to the
nearest 0.1 deg. For the Ursa Major cluster, only the 13 core stars listed
by Soderblom & Mayor (1993, cat. J/AJ/105/226) were used to compute the
centroid.
Note on v0r, e_v0r:
Radial component of the cluster space velocity in the direction
(RA0deg, DE0deg) towards the adopted cluster centroid, and its formal
standard error. v0r is the astrometric radial velocity of the cluster
centroid. e_v0r represents the typical uncertainty in the astrometric radial
velocities of individual stars from the uncertainty of the space velocity
vector. The total uncertainty of the astrometric radial velocities, as
listed in Table 2, includes in addition a contribution from the internal
velocity dispersion.
Note on cxx, cxy, cxz, cyy, cyz, czz:
These are the six non-redundant elements of the 3*3 covariance matrix of
the space velocity vector (v0x,v0y,v0z), as obtained in the
maximum-likelihood solution.
Note on RAcdeg, DEcdeg, v0:
Convergent point in equatorial (ICRS) coordinates, and the total space
velocity, corresponding to the space velocity vector (v0x,v0y,v0z). This
is just an alternative (spherical) specification of the space velocity
vector.
Note on e_RAcdeg, e_DEcdeg, e_v0:
Standard errors of the convergent point coordinates and total velocity.
These were obtained by the normal error propagation formulae, assuming the
given covariance of (v0x,v0y,v0z). The error in right ascension, e_RAcdeg,
is expressed as a true arc, i.e. it includes the factor cos(DEc).
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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 * Hipparcos catalogue number
8- 19 A12 --- Alt * Alternate catalogue number (HD, or other)
21- 26 F6.2 km/s vrH *? Astrometric radial velocity from Hipparcos
28- 32 F5.2 km/s e_vrH *? Standard error in vrH
34- 39 F6.2 km/s vrT *? Astrometric radial velocity from Tycho-2
41- 44 F4.2 km/s e_vrT *? Standard error in vrT
46- 51 F6.2 mas piH *? Kinematically improved parallax from Hipparcos
53- 56 F4.2 mas e_piH *? Standard error in piH
58- 62 F5.2 mas piT *? Kinematically improved parallax from Tycho-2
64- 67 F4.2 mas e_piT *? Standard error in piT
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Note on HIP:
Catalogue number of the star in the Hipparcos Catalogue (ESA 1997, The
Hipparcos and Tycho Catalogues, ESA SP-1200 = Cat. I/239)
Note on Alt:
Alternate identification number for the same star. If only a number is
given, that is the HD number (in the range 1-225300) or of its extension
HDE (range 225301-359083). For stars without an HD/HDE number, the entry is
either the Bonner, Cordoba, or Cape Photographic Durchmusterung (BD, CoD, or
CPD), and when that is lacking, the Melotte number (Mel) for stars in the
Hyades, Pleiades, and Alpha Persei; the entry in The Catalogue of Nearby
Stars (GL; Gliese 1969VeARI..22....1G 1969VeARI..22....1G, Cat. V/35), or its extensions
(GJ; Gliese & Jahreiss 1979A&AS...38..423G 1979A&AS...38..423G, See Cat. V/70);
The Lowell Proper Motion Survey (G; Giclas et al., 1959-78, Cat. I/79 &
I/112); or The Luyten Palomar Survey (LP; Luyten 1963-87). These
identifiers were taken from The Hipparcos Input Catalogue (ESA SP-1136,
1992 = Cat. I/196), in that version that is on the Celestia 2000
CD-ROM (Turon et al., ESA SP-1220, 1998).
Note on vrH, e_vrH:
Estimated astrometric radial velocities and their standard errors obtained
from the kinematic solution using astrometric data from the Hipparcos main
catalogue. These were derived from Eqs.(2) and (3) in the paper, using the
adopted solution in Table 1. The sample of stars producing this astrometric
solution is made up of those with an entry in these columns; stars with a
blank entry were rejected by the programme routines selecting the optimal
sample.
The LaTeX code used in the paper for vrH is $v_r,Hip$, and
that for e_vrH is $ε(v_r,Hip)$.
Note on vrT, e_vrT:
Estimated astrometric radial velocities and their standard errors obtained
from the kinematic solution using astrometric data from the Tycho-2
catalogue. This catalogue includes almost a century of ground-based proper-
motion data, and yields values slightly different from the previous ones.
For the Hyades, the resulting optimal sample of stars was slightly different
from that for the Hipparcos main catalogue (the stars producing the solution
are those with an entry in the respective columns). Solutions with Tycho-2
data were not computed for all clusters.
Note on piH, e_piH:
Kinematically improved parallaxes and their standard errors (in milli-
arcseconds, mas) obtained from the kinematic solution, using astrometric
data from the Hipparcos main catalogue.
The LaTeX code used in the paper for piH is $π_Hip$,
and that for e_piH is $ε(π_Hip)$.
Note on piT, e_piT:
Kinematically improved parallaxes and their standard errors obtained from
the kinematic solution, using astrometric data from the Tycho-2 catalogue.
Analogous to the case for radial velocities, there are slight differences
between the Hipparcos and Tycho-2 solutions. Solutions with Tycho-2 data
were not computed for all clusters.
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Acknowledgements: Soren Madsen
References:
Dravins et al., Paper I 1999A&A...348.1040D 1999A&A...348.1040D
Lindegren et al., Paper II 2000A&A...356.1119L 2000A&A...356.1119L
(End) Patricia Bauer [CDS] 22-Oct-2001