J/A+AS/93/293 Astrometry of globular clusters (47 Tuc) (Tucholke 1992)
Astrometry of globular clusters. I. Relative proper motions for stars in 47 Tuc.
Tucholke H.J.
<Astron. Astrophys. Suppl. Ser. 93, 293 (1992)>
=1992A&AS...93..293T 1992A&AS...93..293T
ADC_Keywords: Clusters, globular ; Positional data ; Proper motions ;
Keywords: clusters: globular: 47 Tuc
Abstract:
The study determines relative proper motions for stars brighter than
17.0mag in a 1.5x1.5° field centered on the globular cluster 47
Tuc (NGC 104). Proper motion and membership probabilities are
tabulated for 3076 stars within 32 arcmin of the cluster center. A
proper motion of 47 Tuc relative to the SMC is derived, which relies
on the assumption that the mean proper motion of field stars is the
same as that in the nearby field of NGC 362, and on the detection of
SMC stars in that field. The resulting space motion confirms the
membership of 47 Tuc in the rapidly rotating, flattened, metal-rich
disk subgroup of the galactic cluster system. Relative proper motions
for stars centered on the globular cluster NGC 362 are determined. NGC
362 is found to exhibit a highly eccentric orbit, typical for a member
of the halo subgroup of the galactic globular cluster system. The
perigalactic distance of NGC 362 is very small (less than about 1kpc).
Description;
The plate material consists in 14 plates observed between 1895 and
1987; the plates were digitized at the Munster Astronomical Institute
(accuracy∼0.7µm). The astrometry reduction uses the Perth-70
catalog (Hog & von der Heide 1976, I/62)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 103 3076 Stars within 45' of 47 Tuc centre
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/3076] Running number
6- 7 A2 --- r_ID [35DE- ] Source of identifier (1)
8- 12 I5 --- ID [15/8756]? Identifier in source r_ID
13 A1 --- u_ID Uncertainty flag (:) for ID
15- 19 F5.2 mag Bmag [11.4/18.8]? Magnitude in B (±0.25mag)
20 A1 --- u_Bmag Uncertainty flag on Bmag
22- 26 F5.2 mag B-R [-0.33/4.7]? Color index (±0.40mag)
27 A1 --- u_B-R Uncertainty flag on B-R
29- 35 F7.1 pix Xpos [-2470/2447] Relative position to adopted
cluster centre (1pix=0.7695arcsec)
37- 43 F7.1 pix Ypos [-2496/2444] Relative position to adopted
cluster centre (1pix=0.7695arcsec)
45- 50 F6.1 mas/yr pmRA Proper motion in RA (µαcos(δ))
52- 54 F3.1 mas/yr e_pmRA Error on pmRA
56- 61 F6.1 mas/yr pmDE Proper motion in Dec (µδ)
63- 65 F3.1 mas/yr e_pmDE Error on pmDE
67 I1 --- N1 Number of first-epoch plates
68 I1 --- N2 Number of second-epoch plates
70- 73 F4.1 % Pr [0/99] Membership probability
75 I1 h RAh Right Ascension B1950 (hours)
(Epoch 1985.5, Perth-70-System, ±0.4")
77- 78 I2 min RAm Right Ascension B1950 (minutes)
80- 85 F6.3 s RAs Right Ascension 1950 (seconds)
87 A1 --- DE- Declination B1950B (sign)
(Epoch 1985.5, Perth-70-System, ±0.4")
88- 89 I2 deg DEd Declination B1950 (degrees)
91- 92 I2 arcmin DEm Declination B1950 (minutes)
94- 98 F5.2 arcsec DEs Declination B1950 (seconds)
100-103 A4 --- Var Variable name (from Table 7)
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Note (1): the origin of the identifier is:
(no prefix) = Lee 1977A&AS...27..381L 1977A&AS...27..381L, <Cl* NGC 104 Lee NNNN> in Simbad
3 = Fig. 3 in Hesser & Hartwick 1977ApJS...33..361H 1977ApJS...33..361H,
<Cl* NGC 104 HH NNNN> in Simbad
5 = Fig. 5 in Hesser & Hartwick 1977ApJS...33..361H 1977ApJS...33..361H,
<Cl* NGC 104 HH NNNN> in Simbad
D = Chun & Freeman 1978AJ.....83..376C 1978AJ.....83..376C, ring "D",
<Cl* NGC 104 Chun D NNN> in Simbad
E = Chun & Freeman 1978AJ.....83..376C 1978AJ.....83..376C, ring "E",
<Cl* NGC 104 Chun E NNNN> in Simbad
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History:
* 09-Apr-1993: Table received from the author
* 23-Feb-2015: Standardized this ReadMe; the variable name (column "Var")
was added.
(End) Francois Ochsenbein [CDS] 09-Apr-1993