J/A+A/243/386 Hyades members distances (Schwan 1991)
The distance and main sequence of the Hyades cluster based on 145 stars with
highly accurate proper motions obtained from work on the catalogues FK5 and PPM.
Schwan H.
<Astron. Astrophys. 243, 386 (1991)>
=1991A&A...243..386S 1991A&A...243..386S (SIMBAD/NED BibCode)
ADC_Keywords: Proper motions ; Space velocities ; Stars, distances ;
Clusters, open
Keywords: open clusters - Hyades distance - Hyades main sequence - CM diagram
Description:
Distances for 145 Hyades members in an extended region of the Hyades
cluster were derived on the basis of new, highly accurate proper
motions obtained from work on the catalogues FK5 and PPM. The cluster
membership on the stars has been discussed and a few new candidates
are proposed. From a selected subset of our sample we have obtained
the convergence point α=6h30.7m±1.7m=97deg41'±25',
δ=5deg59'±11'. Combining this point with the mean cluster
radial velocity of 39.1km/s by Detweiler et al. (1984AJ.....89.1038D 1984AJ.....89.1038D)
one find the galactic space velocity
(U, V, W)=(-42.02, -20.12, -1.04)km/s. The galactic coordinates of the
centre of our sample are (X, Y, Z)=(-44.3, +0.5, -18.2)pc. The
distance of this centre from the Sun is 47.9±0.8pc corresponding to
a modulus m-M=3.40±0.04mag. Individual distance moduli, coordinates
and velocity residuals per star are given. The Hyades main sequence
has been constructed in the range B-V<1.2mag and it is presented
analytically as well as by tabular values. The dispersion
σ(Mv)=0.14mag of the absolute magnitudes about the main
sequence indicates its high internal accuracy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 92 181 Basic data
table2 101 181 Essential data used as membership criterion
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See also:
J/AJ/80/379 : Hyades cluster (Hanson+, 1975)
J/MNRAS/257/257 : Proper motions in the Hyades (Reid 1992)
Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1 I1 --- Member [1/4] Membership flag (1)
3- 5 I3 --- Seq Sequential number
7- 12 I6 --- No Star number in the catalogue (2)
14- 16 A3 --- vB van Bueren (1952BAN....11..385V 1952BAN....11..385V) number (3)
18- 25 A8 --- BD BD number
27- 32 I6 --- HD ? HD number (cat. III/135)
34 I1 h RAh Right ascension (B1950)
36- 37 I2 min RAm Right ascension (B1950)
39- 40 I2 s RAs Right ascension (B1950)
41 A1 --- DE- Declination sign
42- 43 I2 deg DEd Declination (B1950)
45- 46 I2 arcmin DEm Declination (B1950)
48- 51 I4 10-4arcsec/yr pmRA Proper motion in right ascension
53- 54 I2 10-4arcsec/yr e_pmRA rms uncertainty on pmRA
56- 60 I5 10-4arcsec/yr pmDE Proper motion in declination
62- 63 I2 10-4arcsec/yr e_pmDE rms uncertainty on pmDE
65- 69 F5.1 km/s RV ? Radial velocity
71 A1 --- r_RV [GW] References for radial velocity (4)
73- 77 F5.2 mag Vmag V magnitude
79- 82 F4.2 mag B-V B-V colour index
84 A1 --- r_B-V [M+] B-V references (5)
86- 89 F4.2 mag Mv Absolute V magnitude
91- 92 I2 --- w_Mv ? Weight for those stars which were used
in the determination of the convergence
point.
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Note (1): The membership code is as follows:
1: Stars adopted as Hyades members
2: Possible Hyades members
3: Probable non-members
4: van Bueren stars which have been rejected as Hyades members
Note (2): Numbers smaller than 4000 are from the Basic FK5 I/149 or
from the FK4 Sup I/143
Numbers from 4000 to 10000 are N30 I/80 numbers increased by 4000
Numbers exceeding 10000 are the numbers used in the PPM I/146 catalog.
Note (3): Numbers are given from table 2a and 2b in that paper, and
letters "c" or "d" denote stars in table 2c and 2d, respectively.
Note (4): the references are noted
G: Griffin 1988AJ.....96..172G 1988AJ.....96..172G
W: General catalogue of stellar Radial Velocities, III/21
Note (5): the origin is noted
M: from Mermilliod, otherwise from the SIMBAD data base
+: when a reference was found on possible membership
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1 I1 --- Member [1/4] Membership flag (1)
3- 8 I6 --- No Star number in the catalogue as in table1
10- 13 F4.1 pc r Distance
15- 18 F4.2 mag m-M Distance modulus
20- 24 F5.1 pc X-Xc Residual X coordinate (2)
25 A1 --- n_X-Xc [*] *: discordant value
26- 30 F5.1 pc Y-Yc Residual Y coordinate (2)
31 A1 --- n_Y-Yc [*] *: discordant value
32- 36 F5.1 pc Z-Zc Residual Z coordinate (2)
37 A1 --- n_Z-Zc [*] *: discordant value
39- 43 F5.2 km/s U-Uc Residual U velocity (2)
45- 49 F5.2 km/s V-Vc Residual V velocity (2)
51- 55 F5.2 km/s W-Wc Residual W velocity (2)
57- 62 F6.2 deg d-Teta Angle between the star's proper motion and
the direction of the convergence point
63 A1 --- n_d-Teta [*] *: discordant value
65- 69 F5.2 0.01arcsec/yr My-Tau Velocity component perpendicular to the
direction to the convergence point in
angular measure
72- 75 F4.2 0.01arcsec/yr e_My-Tau rms uncertainty on My-Tau
77- 81 F5.2 km/s V-Tau Velocity component perpendicular to the
direction to the convergence point in
linear measure
84- 87 F4.2 km/s e_V-Tau rms uncertainty on V-Tau
89- 93 F5.1 km/s d-Vr ? Difference between the observed and
expected radial velocity
94 A1 --- n_d-Vr [*] *: discordant value
96-100 F5.2 mag d-Mv Difference between the observed and
expected magnitude
101 A1 --- n_d-Mv [*] *: discordant value
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Note (1): The membership code is as follows:
1: Stars adopted as Hyades members
2: Possible Hyades members
3: Probable non-members
4: van Bueren stars which have been rejected as Hyades members
Note (2): Data with respect to the cluster center (see Table 2b)
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Table 2a: Mean values for our sample
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Ro (m-M)o Xo Yo Zo Uo Vo Wo
pc mag pc pc pc km/s km/s km/s
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49.5 3.47 -46.2 +0.3 -17.7 -42.06 -20.05 -0.98
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Table 2b: The centre of the Hyades cluster
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Rc (m-M)c Xc Yc Zc Uc Vc Wc
pc mag pc pc pc km/s km/s km/s
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47.9 3.40 -44.3 +0.5 -18.2 -42.02 -20.12 -1.04
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Acknowledgements: Heiner Schwan
(End) Patricia Bauer [CDS] 12-Nov-1996