J/A+A/379/453 CCD BVI photometry of 5 open cluster candidates (Piatti+, 2001)
On the nature of five open cluster candidates projected close to the
Galactic centre
Piatti A.E., Claria J.J.
<Astron. Astrophys. 379, 453 (2001)>
=2001A&A...379..453P 2001A&A...379..453P
ADC_Keywords: Clusters, open ; Photometry, CCD
Keywords: open clusters and associations: individual:
Ruprecht 103, 124, 129, 146, and 166 -
open clusters and associations : general
Abstract:
We present CCD BVI observations obtained for 1759 stars in 4'x4'
regions around the unstudied southern stellar aggregates Ruprecht 103,
124, 129, 146 and 166, which are described as open clusters in several
catalogues. Our analysis shows that none of these stellar groups are
genuine open clusters since no clear main sequences or other
meaningful features can be seen in their colour-magnitude diagrams.
Star counts carried out within and outside the cluster candidate
fields not only support these results but also show that the studied
objects do not appear to be candidate late stages of star cluster
dynamical evolution.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
12 15 54 -58 25.0 Cl Ruprecht 103
17 28 00 -40 46.0 Cl Ruprecht 124
17 47 18 -29 36.0 Cl Ruprecht 129
18 52 36 -21 07.0 Cl Ruprecht 146
13 26 06 -63 25.0 Cl Ruprecht 166
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 70 163 Stars in the field of Ruprecht 103
table3.dat 70 424 Stars in the field of Ruprecht 124
table4.dat 70 55 Stars in the field of Ruprecht 129
table5.dat 70 163 Stars in the field of Ruprecht 146
table6.dat 70 954 Stars in the field of Ruprecht 166
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Byte-by-byte Description of file: table[2-6].dat
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Bytes Format Units Label Explanations
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4- 6 I3 --- ID Star number
8- 14 F7.3 pix Xpix X coordinate (1)
16- 22 F7.3 pix Ypix Y coordinate (1)
24- 29 F6.3 mag Vmag V magnitude
32- 36 F5.3 mag e_Vmag rms uncertainty on Vmag
39- 44 F6.3 mag B-V B-V colour index
47- 51 F5.3 mag e_B-V rms uncertainty on B-V
54- 59 F6.3 mag V-I V-I colour index
62- 66 F5.3 mag e_V-I rms uncertainty on V-I
70 I1 --- o_Vmag Number of measurements
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Note (1): For all fields, 1 pix = 0.45". North is up and East is to the left.
Positions for the centres of the circles drew in Fig. 1:
Object X (pixels) Y(pixels)
-----------------------------------
Ru103 180 240
Ru124 260 285
Ru129 220 265
Ru146 240 300
Ru146 240 300
-----------------------------------
None of these stellar groups are genuine open clusters, so that the
above centres only refers to positions around which the stellar
density is higher than in any other region of the observed fields.
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Acknowledgements: Andres Piatti
(End) Patricia Bauer [CDS] 12-Nov-2001