J/A+A/415/145 Radial velocities of 16 stars in NGC 6913 (Boeche+, 2004)
Kinematics and binaries in young stellar aggregates. II. NGC 6913 = M29.
Boeche C., Munari U., Tomasella L., Barbon R.
<Astron. Astrophys. 415, 145 (2004)>
=2004A&A...415..145B 2004A&A...415..145B
ADC_Keywords: Clusters, open ; Stars, early-type ; Binaries, eclipsing ;
Radial velocities
Keywords: stars: binaries: spectroscopic - stars: early type - ISM: bubbles -
open clusters and associations: general -
open clusters and associations: individual (NGC 6913)
Abstract:
Between 1996 and 2003 we obtained 226 high resolution spectra of 16
stars in the field of the young open cluster NGC 6913, to constrain
its main properties and study its internal kinematics. Twelve of the
program stars turned out to be members, one of them probably unbound.
Nine are binaries (one eclipsing and another double lined) and for
seven of them the observations allowed us to derive the orbital
elements. All but two of the nine discovered binaries are cluster
members. In spite of the young age (a few Myr), the cluster already
shows signs that could be interpreted as evidence of dynamical
relaxation and mass segregation. However, they may be also the result
of an unconventional formation scenario. The dynamical (virial) mass
as estimated from the radial velocity dispersion is larger than the
cluster luminous mass, which may be explained by a combination of the
optically thick interstellar cloud that occults part of the cluster,
the unbound state or undetected very wide binary orbit of some of the
members that inflate the velocity dispersion and a high inclination
for the axis of possible cluster angular momentum. All the discovered
binaries are hard enough to survive average close encounters within
the cluster and do not yet show signs of relaxation of the orbital
elements to values typical of field binaries.
Description:
226 epoch radial velocities are provided for 16 stars belonging to the
field of NGC 6913 (Table 4 of the article available in electronic form
only). They have been derived from high resolution Echelle+CCD spectra
secured with the Asiago 1.82 m telescope of the Astronomical
Observatory of Padova between 1996 and 2003. Numbering convention for
the sixteen targets is given in Table 1 of the article, where
cross-identification with the catalogues of Hoag et al.
(1961PUSNO..17..343H 1961PUSNO..17..343H) and Kazlauskas and Jasevicius
(1986VilOB..75...18K 1986VilOB..75...18K) is provided.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 62 16 Star positions (from Simbad)
table4.dat 29 240 Epoch radial velocities of the program stars
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See also:
J/A+A/343/806 : The trapezium system BD+00 1617 (Munari+ 1999)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Sequential number
4- 5 I2 h RAh Right ascension (J2000.0)
7- 8 I2 min RAm Right ascension (J2000.0)
10- 13 F4.1 s RAs Right ascension (J2000.0)
15 A1 --- DE- Declination sign (J2000.0)
16- 17 I2 deg DEd Declination (J2000.0)
19- 20 I2 arcmin DEm Declination (J2000.0)
22- 23 I2 arcsec DEs Declination (J2000.0)
26- 40 A15 --- HIP/TYC HIP or TYC designation
44- 65 A22 --- Name Other name
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Star number as given in the paper
3 A1 --- m_Seq [AB] Multiplicity index on Seq
5- 15 F11.3 d HJD Epoch of observation in heliocentric Julian days
17- 22 F6.1 km/s HRV Heliocentric radial velocity
24- 27 F4.1 km/s e_HRV rms uncertainty on HRV
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Acknowledgements: C. Boeche
References:
Munari et al., Paper I 1999A&A...343..806M 1999A&A...343..806M, Cat. J/A+A/343/806
(End) Patricia Bauer [CDS] 28-Nov-2003