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J/A+A/331/81        Hyades membership (Perryman+ 1998)

The Hyades: distance, structure, dynamics, and age Perryman M.A.C., Brown A.G.A., Lebreton Y., Gomez A., Turon C., Cayrel de Strobel G., Mermilliod J.C., Robichon N., Kovalevsky J., Crifo F. <Astron. Astrophys. 331, 81 (1998)> =1998A&A...331...81P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Radial velocities ; Stars, distances ; Parallaxes, trigonometric Keywords: astrometry - parallaxes - HR Diagram - Hyades - distance scale Abstract: We use absolute trigonometric parallaxes from the Hipparcos Catalogue (Cat. I/239) to determine individual distances to members of the Hyades cluster, from which the 3-dimensional structure of the cluster can be derived. Inertially-referenced proper motions are used to rediscuss distance determinations based on convergent-point analyses. A combination of parallaxes and proper motions from Hipparcos, and radial velocities from ground-based observations, are used to determine the position and velocity components of candidate members with respect to the cluster centre, providing new information on cluster membership: 13 new candidate members within 20pc of the cluster centre have been identified. Farther from the cluster centre there is a gradual merging between certain cluster members and field stars, both spatially and kinematically. Within the cluster, the kinematical structure is fully consistent with parallel space motion of the component stars with an internal velocity dispersion of about 0.3km/s. The spatial structure and mass segregation are consistent with N-body simulation results, without the need to invoke expansion, contraction, rotation, or other significant perturbations of the cluster. The quality of the individual distance determinations permits the cluster zero-age main sequence to be accurately modelled. The helium abundance for the cluster is determined to be Y=0.26±0.02 which, combined with isochrone modelling including convective overshooting, yields a cluster age of 625±50Myr. The distance to the observed centre of mass (a concept meaningful only in the restricted context of the cluster members contained in the Hipparcos Catalogue) is 46.34±0.27pc, corresponding to a distance modulus m-M=3.33±0.01mag for the objects within 10pc of the cluster centre (roughly corresponding to the tidal radius). This distance modulus is close to, but significantly better determined than, that derived from recent high-precision radial velocity studies, somewhat larger than that indicated by recent ground-based trigonometric parallax determinations, and smaller than those found from recent studies of the cluster convergent point. These discrepancies are investigated and explained. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 107 282 Data on the membership of the Hyades for the 282 stars in the sample of Perryman et al.
See also: I/239 : The Hipparcos and Tycho Catalogues (ESA 1997) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 5 I5 --- HIP Hipparcos Catalogue (HIP, Cat. I/239) number 7- 9 I3 --- vB ? van Bueren number (1952BAN....11..385V) 10 A1 --- n_vB [n] n: new candidate proposed in this paper 12 I1 --- MembvB [0/1]? Membership according to van Bueren (1) 14- 16 I3 --- vA ? van Altena number (1969AJ.....74....2V) 17 A1 --- n_vA [n] n: new candidate proposed in this paper 19 I1 --- MembvA [0/1]? Membership according to van Altena (1) 21- 23 I3 --- Han ? Hanson number (1975, Cat. J/AJ/80/379) 24 A1 --- n_Han [n] n: new candidate proposed in this paper 26 I1 --- MembHan [0/1]? Membership according to Hanson (1) 28- 31 I4 --- Pel ? Pels et al. (1975A&A....43..423P) (Leiden) number, van Bueren stars have the vB number + 1000 32 A1 --- n_Pel [n] n: new candidate proposed in this paper 34 I1 --- MembPel [0/1]? Membership according to Pels et al. (1) 36- 38 I3 --- Grif ? Sequential number in Table4 of Griffin et al. (1988AJ.....96..172G) 39 A1 --- n_Grif [n] n: new candidate proposed in this paper 41 I1 --- MembGrif [0/1]? Membership according to Griffin et al. (1) 43- 45 I3 --- Scha ? Schwan number (1991A&A...243..386S) 46 A1 --- n_Scha [n] n: new candidate proposed in this paper 48 I1 --- MembScha [0/1]? Membership according to Schwan (1) 50- 56 F7.2 mas plx Hipparcos parallax (milliarcsec=mas) 58- 63 F6.2 mas e_plx Hipparcos parallax standard error 65- 71 F7.2 km/s RV ? Radial velocity 72 A1 --- u_RV [?] Uncertainty flag on RV 73 A1 --- n_RV [#] # indicates SB/RV with undetermined gamma velocity 74- 77 F4.2 km/s e_RV ? Error in radial velocity 80- 81 I2 --- r_RV ? Source of radial velocity (2) 83- 84 A2 --- Note [SB RV] SB: spectroscopic binary, RV: radial velocity (possibly) variable 86 A1 --- Note2 [HIM] Historical status flag (3) 88- 90 A3 --- Note3 [CGOVX S/] Double/Multiple Systems flag (4) 92- 97 F6.1 pc Dist Distance from the cluster centre defined by the 134 stars within r<10 pc (see Table 3) 99-105 F7.2 --- Stat Kinematic statistic (5) 107 A1 --- Memb [0/1?] Final membership assigned in this paper `?' indicates possible new members unclassifiable due to unknown radial velocities
Note (1): Data on the membership of the Hyades for the 282 stars in our sample, listed by various authors. Membership or non-membership inferred by the relevant authors are indicated by `1' or `0' in the corresponding column respectively (see paper for details). Note (2): Sources of radial velocities: (0) Radial velocity unknown; (1) Griffin et al., 1988AJ.....96..172G 1985AJ.....90..609G 1981AJ.....86..588G 1978AJ.....83.1114G 1977AJ.....82..176G 1982A&A...106..221G (2) Hipparcos Input Catalogue, Cat. I/196 (mainly from R.E. Wilson, 1953, Cat. III/21) (3) Weighted mean of ref. 2 (39.6±1.2) and Kraft, 1965ApJ...142..681K (38.4±1.5) (4) Kraft, 1965ApJ...142..681K (37.4±0.4 and 36.5±0.5) Cheriguene, 1971A&A....13..447C (37.3±0.7) (5) McClure, 1982ApJ...254..606M (6) Torres et al., 1997ApJ...474..256T (7) Mayor & Mazeh, 1987A&A...171..157M (8) Kraft, 1965ApJ...142..681K (9) Margoni et al., 1992A&AS...93..545M (10) Lucy & Sweeney, 1971AJ.....76..544L (11) Abt & Levy, 1985ApJS...59..229A (12) Griffin, 1971MNRAS.155....1G (13) Andersen & Nordstrom, 1983A&A...122...23A (14) Morse et al., 1991AJ....101.1495M (15) Detweiler et al., 1984AJ.....89.1038D (16) Weighted mean of data from Palmer et al., 1968RGOB..135..385P and Stillwell, 1948PDAO....7..337S (17) Tomkin et al., 1995AJ....109..780T (18) Heintz, 1981ApJS...46..247H (19) Abt, 1965ApJS...11..429A (20) Fekel, 1980PASP...92..785F (21) Perraud, 1962JO.....45..361P (22) Fouts & Sandage, 1986AJ.....91.1189F, Cat. III/144 (star G83-18) (23) Strassmeier et al., 1988A&AS...72..291S, See Cat. V/76 (24) New Coravel observations provided by J.C. Mermilliod (25) Woolley et al., 1971ROAn...14....1W (26) Hanson & Vasilevskis, 1983AJ.....88..844H (27) Evans, 1978BICDS..15..121E (28) Orbit recomputed by Mermilliod with period=490±1d (from Batten) Note (3): Star was previously known, or classified by Hipparcos, to have resolved components (from Field H56, Cat. I/239); this may overlap with the flag in the next column, but may also indicate visual or wide binary (see paper for details) H : determined multiple by Hipparcos, previously unknown I : system previously identified as multiple in HIC I/196 (annex1) M : miscellaneous (system identified after publication of HIC) Note (4): C, G, O, V, or X = relevant part of the Hipparcos Double and Multiple Systems Annex, from Field H59 (Cat. I/239), C: solutions for the components G: acceleration or higher order terms O: orbital solutions V: variability-induced movers (apparent motion arises from variability) X: stochastic solution (probably astrometric binaries with short period) supplemented by S = suspected binary in Hipparcos Catalogue, from Field H61, Cat. I/239, (see paper for details) Note (5): A value of 14.16 corresponding to 3σ, see paper for details.
Acknowledgements: Anthony Brown
(End) Patricia Bauer [CDS] 24-Jul-1997
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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