J/AJ/112/1489 Spectroscopic survey for binaries in NGC 5053 (Yan+ 1996)
A spectroscopic survey for binary stars in the globular cluster NGC 5053.
Yan L., Cohen J.G.
<Astron. J. 112, 1489 (1996)>
=1996AJ....112.1489Y 1996AJ....112.1489Y
ADC_Keywords: Clusters, globular ; Binaries, spectroscopic ; Radial velocities
Abstract:
We carried our a radial velocity survey for spectroscopic binaries in
the low-density globular cluster NGC 5053. Our sample contains a total
of 77 cluster member giant and subgiant stars with visual magnitudes
of 14.5-18.6. Of These 77 stars, 66 stars have on average of 3-4
measurements with a total of 236 velocities. A typical velocity error
per measurement is 13km/s. The stars in our sample are spatially
distributed from the cluster center out to 10arcmin in radius (4.5
core radii). Among theses 66 stars with multiple velocity
measurements, we discovered 6 spectroscopic binary candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2a 62 248 Relative radial velocities of stars in NGC 5053
(individual data)
table2b 78 77 Relative radial velocities of stars in NGC 5053
(average data)
table2.tex 234 469 TeX version of table 2
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Byte-by-byte Description of file: table2a
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Bytes Format Units Label Explanations
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1- 5 A5 --- Star Star identification name
7- 8 I2 h RAh Right ascension (1950)
10- 11 I2 min RAm Right ascension (1950)
13- 18 F6.3 s RAs Right ascension (1950)
19 A1 --- DE- Declination sign
20- 21 I2 deg DEd Declination (1950)
23- 24 I2 arcmin DEm Declination (1950)
26- 31 F6.3 arcsec DEs Declination (1950)
33- 37 F5.1 arcsec Dist Radial distance from the cluster
39- 50 F12.4 d HJD Heliocentric Julian date of observation
52- 56 F5.1 km/s HRV Heliocentric radial velocity
58- 61 F4.1 km/s e_HRV rms uncertainty on HRV
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Byte-by-byte Description of file: table2b
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Bytes Format Units Label Explanations
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1- 5 A5 --- Star Star identification name
7- 8 I2 h RAh Right ascension (1950)
10- 11 I2 min RAm Right ascension (1950)
13- 18 F6.3 s RAs Right ascension (1950)
19 A1 --- DE- Declination sign
20- 21 I2 deg DEd Declination (1950)
23- 24 I2 arcmin DEm Declination (1950)
26- 31 F6.3 arcsec DEs Declination (1950)
33- 37 F5.1 arcsec Dist Radial distance from the cluster
39- 40 I2 --- o_VR Number of observations
42- 46 F5.1 km/s VR Weighted mean radial velocity (1)
48- 51 F4.1 km/s e_VR External velocity error in a single
measurement estimated from the dispersion
about the mean
53- 60 F8.3 --- chi2 ? Radial velocity variability over the
timespan of three years
62- 67 F6.4 --- P(<chi2) ? Probability (2)
69- 73 F5.2 mag V0mag Deredenned V magnitude (3)
75- 78 F4.2 mag (B-V)0 ? Deredenned B-V colour index (3)
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Note (1): When o_VR=1, only one measurement
Note (2): To evaluate the significance of the variations represented by chi2,
we calculated the probability P(<chi2) of having a chi2 at least
this large purely due to chance fluctuations with a Gamma function
Q(0.5ν, 0.5chi2), here ν is the number of the degree of
freedom. Reasonable limits of chi2 probability for identifying
significant variations are 0.01-0.001.
Note (3): Photmetry for stars beginning by S is from
Sandage et al. (1977AJ.....82..389S 1977AJ.....82..389S)
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Acknowledgements: Lin Yan
(End) Patricia Bauer [CDS] 17-Nov-1997