J/A+A/485/95 Velocities of F-G-K stars in Blanco 1 (Mermilliod+, 2008)
Membership, binarity, and rotation of F-G-K stars in the open cluster Blanco 1.
Mermilliod J.-C., Platais I., James D.J., Grenon M., Cargile P.A.
<Astron. Astrophys. 485, 95 (2008)>
=2008A&A...485...95M 2008A&A...485...95M
ADC_Keywords: Clusters, open ; Stars, dwarfs ; Photometry, UBVRI ;
Proper motions ; Radial velocities
Keywords: Galaxy: open clusters and associations: general -
Galaxy: open clusters and associations: individual: Zeta Scl -
techniques: radial velocities - techniques: photometric
Abstract:
The nearby open cluster Blanco 1 is of considerable astrophysical
interest for formation and evolution studies of open clusters because
it is the third highest Galactic latitude cluster known. It has been
observed often, but so far no definitive and comprehensive membership
determination is readily available.
An observing programme was carried out to study the stellar population
of Blanco 1, and especially the membership and binary frequency of the
F5-K0 dwarfs.
We obtained radial-velocities with the CORAVEL spectrograph in the
field of Blanco 1 for a sample of 148 F-G-K candidate stars in the
magnitude range 10<V<14. New proper motions and UBVI CCD
photometric data from two extensive surveys were obtained
independently and are used to establish reliable cluster membership
assignments in concert with radial-velocity data.
The membership of 68 stars is confirmed on the basis of proper motion,
radial velocity, and photometric criteria. Fourteen spectroscopic- and
suspected binaries (2 SB2s, 9 SB1s, 3SB?) have been discovered among
the confirmed members. Thirteen additional stars are located above the
main sequence or close to the binary ridge, with radial velocities and
proper motions supporting their membership. These are probable
binaries with wide separations. Nine binaries (7 SB1 and 2 SB2) were
detected among the field stars. The spectroscopic binary frequency
among members is 20% (14/68); however, the overall binary rate reaches
40% (27/68) if one includes the photometric binaries.
The cluster mean heliocentric radial velocity is +5.53±0.11km/s
based on the most reliable 49 members.
The Vsini distribution is similar to that of the Pleiades, confirming
the age similarities between the two clusters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 117 148 Mean radial velocities and general information
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See also:
J/A+AS/121/213 : BV photometry of Blanco 1 stars (Panagi+, 1997)
J/A+A/399/919 : X-ray Luminosities in Blanco 1 (Pillitteri+, 2003)
J/A+A/421/175 : XMM sources in Blanco 1 (Pillitteri+, 2004)
J/MNRAS/364/272 : Elemental abundances in Blanco 1 (Ford+, 2005)
J/A+A/471/499 : Low-mass stars and brown dwarfs in Blanco 1 (Moraux+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- WEBDA Star designation (WEBDA) in Blanco 1
6- 8 I3 --- SA140 ? Star number from SA 140
10- 12 I3 --- ZS ? Number from de Epstein & Epstein
(1985AJ.....90.1211D 1985AJ.....90.1211D) (1)
14- 15 I2 h RAh Right ascension (J2000, Ep=J2005.71)
17- 18 I2 min RAm Right ascension (J2000, Ep=J2005.71)
20- 24 F5.2 s RAs Right ascension (J2000, Ep=J2005.71)
26 A1 --- DE- Declination sign (J2000, Ep=J2005.71)
27- 28 I2 deg DEd Declination (J2000, Ep=J2005.71)
30- 31 I2 arcmin DEm Declination (J2000, Ep=J2005.71)
33- 36 F4.1 arcsec DEs Declination (J2000, Ep=J2005.71)
38- 42 F5.2 mag Vmag V magnitude
44- 47 F4.2 mag B-V ? B-V colour index
49- 53 F5.2 mag U-B ? U-B colour index
55- 58 F4.2 mag V-I ? V-I colour index
60- 65 F6.2 km/s RV Mean radial velocity
67- 71 F5.2 km/s e_RV Error on the radial velocity
73- 74 I2 --- o_Vmag Number of measurements
76- 79 I4 d Dt ? Time interval spent by the observations
81- 85 F5.3 --- prVar ? Probability of variability P(chi2)
87- 90 F4.1 km/s Vsini Projected rotational velocity
92- 95 F4.1 km/s e_Vsini Error on the rotational velocity
97-101 F5.1 mas/yr pmRA Proper motion in Right Ascension
103-107 F5.1 mas/yr pmDE Proper motion in Declination
109-110 I2 % Mm Astrometric membership probability
112-117 A6 --- Notes Membership, or duplicity
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Note (1): Cl* Blanco 1 ZS NNNa in Simbad
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Acknowledgements:
Jean-Claude Mermilliod, Jean-Claude.Mermilliod(at)obs.unige.ch
(End) Patricia Vannier [CDS] 29-Apr-2008