J/A+AS/146/251 Open clusters absolute proper motions. I. (Baumgardt+, 2000)
Absolute proper motions of open clusters. I. Observational data.
Baumgardt H., Dettbarn C., Wielen R.
<Astron. Astrophys. Suppl. Ser. 146, 251 (2000)>
=2000A&AS..146..251B 2000A&AS..146..251B
ADC_Keywords: Clusters, open ; Proper motions ; Parallaxes, trigonometric
Keywords: Galaxy: open clusters and associations: general - Astrometry -
stars: variables: Cepheids
Abstract:
Mean proper motions and parallaxes of 205 open clusters were
determined from their member stars found in the Hipparcos (I/239)
Catalogue. 360 clusters were searched for possible members, excluding
nearby clusters with distances D<200pc. Members were selected using
ground based information (photometry, radial velocity, proper motion,
distance from the cluster centre) and information provided by
Hipparcos (proper motion, parallax). Altogether 630 certain and 100
possible members were found. A comparison of the Hipparcos parallaxes
with photometric distances of open clusters shows good agreement. The
Hipparcos data confirm or reject the membership of several Cepheids in
the studied clusters.
Description:
File table1 contains the Hipparcos stars in the fields of open
clusters. Listed are members and possible members together with some
non-members that could be found in the 'Database for Galactic Open
Clusters' (BDA). The total number of stars is 1103.
File table2 contains the mean astrometric parameters of the open
clusters, calculated as outlined in section 6 of the paper.
Astrometric solutions could be found for 205 open clusters.
File notes contains notes to some stars and clusters of table1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
objects.dat 55 251 Cluster positions (from Simbad)
table1.dat 49 1103 List of Hipparcos stars in the fields of open
clusters
table2.dat 132 205 Mean astrometric parameters of open clusters
notes.dat 80 192 Individual notes
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/250 : The Tycho Reference Catalogue (Hog+ 1998)
http://obswww.unige.ch/webda/ : Database of Stellar Open Clusters (BDA)
Byte-by-byte Description of file: objects.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Cluster name
10 A1 --- Note [*] indicates a note in file "notes.dat"
11- 12 I2 h RAh Right ascension (J2000.0)
14- 15 I2 min RAm Right ascension (J2000.0)
17- 20 F4.1 s RAs Right ascension (J2000.0)
22 A1 --- DE- Declination sign (J2000.0)
23- 24 I2 deg DEd Declination (J2000.0)
26- 27 I2 arcmin DEm Declination (J2000.0)
29- 30 I2 arcsec DEs ? Declination (J2000.0)
33- 52 A20 ---- SName Name in Simbad if different than those in Name
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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 Cluster Name
14- 19 I6 --- HIP Hipparcos number of star
25- 29 A5 --- BDA Number of star in BDA database
34- 36 A3 --- Minf Membership information (1)
43- 47 F5.1 --- Mprob ? Membership probability (2)
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Note (1): Membership information:
M = Member
PM = Probable Member
NM = Non-Member
* = star is binary and not used to derive the proper motion
Note (2): Membership probability derived by comparing proper motion
of star with cluster proper motion.
A blank field indicates stars in clusters which do not have enough
members to derive membership probabilities
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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- 9 A9 --- Name Cluster Name
10 A1 --- Note [*] indicates a note in file "notes.dat"
11- 12 I2 --- Ntot Total number of stars in Hipparcos
20- 21 I2 --- Nuse Number of stars used to derive astrometric
parameters
29- 33 F5.2 mas Plx Mean cluster parallax (1)
39- 42 F4.2 mas e_Plx Error of parallax
46- 51 F6.2 mas/yr pmRA Mean cluster proper motion in RA (2)
56- 60 F5.2 mas/yr e_pmRA Error of proper motion in RA
64- 69 F6.2 mas/yr pmDE Mean cluster proper motion in DE
74- 78 F5.2 mas/yr e_pmDE Error of proper motion in DE
82- 85 I4 --- Nabs ? Total number of abscissae (3)
93- 94 I2 --- Nrej ? Number of rejected abscissae (3)
101-104 F4.2 --- UWSD ? Unit weight standard deviation (3)
110-114 F5.2 --- Plx:pmRA Correlation coefficient between parallax and
proper motion in right ascension
119-123 F5.2 --- Plx:pmDE Correlation coefficient between parallax and
proper motion in declination
128-132 F5.2 --- pmRA:pmDE Correlation coefficient between the proper
motion components
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Note (1): Solution for clusters with one member taken directly from Hipparcos
Note (2): Proper motion in right ascension multiplied by cosine of declination
Note (3): Empty if cluster solution is taken directly from Hipparcos
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Cluster Name
11- 80 A70 --- Note Text of the note
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Acknowledgements: Holger Baumgardt
(End) Patricia Bauer [CDS] 12-Oct-2000