J/PASP/110/1172 NGC 7789 radial velocities (Gim+, 1998)
The open cluster NGC 7789. I. Radial velocities for giant stars.
Gim M., Hesser J.E., McClure R.D., Stetson P.B.
<Publ. Astron. Soc. Pac. 110, 1172 (1998)>
=1998PASP..110.1172G 1998PASP..110.1172G
ADC_Keywords: Clusters, open ; Radial velocities ; Stars, variable
Keywords: galaxy: open clusters and associations: individual: NGC 7789 -
stars: binaries: spectroscopic - techniques: radial velocities
Abstract:
A total of 597 radial velocity observations for 112 stars in the
∼1.6Gyr old open cluster NGC 7789 have been obtained since 1979 with
the radial velocity spectrometer at the Dominion Astrophysical
Observatory. The mean cluster radial velocity is -54.9±0.12km/s and
the dispersion is 0.86km/s, from 50 constant velocity stars selected
as members from this radial velocity study and the 1981 proper motion
study of McNamara & Solomon (1981A&AS...43..337M 1981A&AS...43..337M). Twenty-five stars
(32%) among 78 members are possible radial velocity variable stars,
but no orbits are determined because of the sparse sampling. Seventeen
stars are radial velocity nonmembers, while the membership estimates
of six stars are uncertain. There is a hint that the observed velocity
dispersion falls off at large radius: this may be due to the inclusion
of long-period binaries preferentially in the central area of the
cluster. The known radial velocity variables also seem to be more
concentrated toward the center than members with constant velocity.
Although this is significant at only the 85% level, when combined with
the similar result of Raboud & Mermilliod (1994A&A...289..121R 1994A&A...289..121R) for
three other clusters, the data strongly support the conclusion that
mass segregation is being detected.
Objects:
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RA (2000) DE Designation(s)
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23 57 00 +56 42 54 NGC 7789 = C 2354+564 = OCl 269.0
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 30 592 Radial velocity spectrometer observational data
table3.dat 70 124 Radial velocity results in NGC 7789
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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- 5 A5 --- Name Star name (1)
7- 17 F11.3 d HJD ? Heliocentric Julian date
19- 24 F6.2 km/s RV ? Radial velocity
26- 29 F4.2 km/s e_RV ? rms uncertainty on RV
30 A1 --- n_RV [ab] Note (2)
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Note (1): K: Kuestner, 1923VeUSB..18.....K 1923VeUSB..18.....K
M: McNamara & Solomon, 1981A&AS...43..337M 1981A&AS...43..337M
(Cl* NGC 7789 M NNNN in Simbad)
Note (2): a: Unused because errors are greater than 1.0km/s
b: Unused because the quality was deemed to be dubious
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Kuestner (1923) or McNamara & Solomon
identification number
7- 11 A5 --- M McNamara & Solomon (1981A&AS...43..337M 1981A&AS...43..337M)
identification number
13- 16 I4 --- G ? Gim (1998) identification number
18- 23 F6.3 mag Vmag ? V magnitude
25- 29 F5.3 mag V-I ? V-I colour index
31- 36 F6.2 km/s RV ? Radial velocity
38- 39 I2 10-2km/s e_RV ? rms uncertainty on RV (internal error)
41- 42 I2 --- o_RV ? Number of observations used in the
statistical analysis
44- 50 F7.2 d Days ? Number of days between first and last
observations
52- 56 F5.2 --- E/I ? External over internal errors ratio
58- 62 F5.3 --- P(chi2) ? Probability that velocity variations are due
to random observational errors
64- 65 I2 --- Mempm ? Membership probability by proper motion
(McNamara & Solomon, 1981A&AS...43..337M 1981A&AS...43..337M)
67 A1 --- MemRV [YN] Membership by radial velocity
(Scott et al., 1995AJ....109.1706S 1995AJ....109.1706S)
69- 70 A2 --- Mem Membership adopted in this study (1)
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Note (1): MC: members with constant velocity
MV: members with variable velocity
M: members with one or no velocity data
NM: nonmembers
U: stars with uncertain membership
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History: From PASP electronic version
References:
Kustner, 1923, Veroeff. Univ. Sternw. Bonn, 18
Gim, 1998, M.Sc. thesis, Univ. Victoria
McNamara & Solomon, 1981A&AS...43..337M 1981A&AS...43..337M
(End) James Marcout, Patricia Bauer [CDS] 08-Dec-1998