J/A+A/464/573 VI photometry of 5 open clusters (Carraro+, 2007)
Photometry of the five marginally studied open clusters
Collinder 74, Berkeley 27, Haffner 8, NGC 2509, and VdB-Hagen 4.
Carraro G., Costa E.
<Astron. Astrophys. 464, 573 (2007)>
=2007A&A...464..573C 2007A&A...464..573C
ADC_Keywords: Clusters, open ; Photometry, CCD
Keywords: open clusters and associations: general -
stars: Hertzsprung-Russell (HR) and C-M diagrams
Abstract:
The stellar populations in the outer Galactic disk are a subject of
wide interest nowadays. To contribute to a better picture of this part
of the Galaxy, we have studied the nature of five marginally
investigated star clusters (Collinder 74, Berkeley 27, Haffner 8, NGC
2509, and VdB-Hagen4) by means of accurate CCD photometry in the V and
I passbands. These clusters are in fact located in the third Galactic
quadrant.
We aim to obtain the basic parameters of these objects, which in some
cases are still disputed in the literature. In the case of VdB-Hagen 4
we provide the first estimate of its fundamental parameters, while
for Haffner 8 we present the first CCD photometry.
The analysis is based on the comparison between field star
decontaminated color-magnitude diagrams and stellar models. Particular
care is devoted to the the assessment of the data quality and the
statistical field star decontamination. The Padova library of stellar
isochrones is adopted in this study.
The analysis we carried out allowed us to solve a few inconsistencies
in the literature regarding Haffner 8 and NGC 2509. Collinder 74 is
found to be significantly older than reported before. VdB-Hagen 4 is a
young open cluster located more than 20kpc from the Galactic center.
Such an extreme distance is compatible with the cluster belonging to
the Norma-Cygnus arm.
Objects:
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RA (2000) DE Designation(s) (files)
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06 51 18 +05 46.0 Cl Berkeley 27 = C 0648+058 (table1)
07 23 24 -12 20.0 Cl Haffner 8 = C 0721-122 (table2)
08 00 42 -19 04.0 NGC 2509 = C 0758-189 (table3)
05 48 30 +07 24.0 Cl Collinder 74 = C 0545+073 (table4)
07 37 48 -36 02.0 Cl VdBH 4 = C 0736-359 (table5)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 4632 Photometry of Berkeley 27
table2.dat 65 4746 Photometry of Haffner 8
table3.dat 65 2995 Photometry of NGC 2509
table4.dat 65 2198 Photometry of Collinder 74
table5.dat 65 8353 Photometry of VdB-Hagen 4
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Byte-by-byte Description of file: table?.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq Star sequential number in the cluster
8- 15 F8.3 pix Xpos X position (1)
18- 25 F8.3 pix Ypos Y position (1)
29- 35 F7.4 mag Vmag Johnson V magnitude
40- 45 F6.4 mag e_Vmag Error in V magnitude
49- 55 F7.4 mag Icmag Cousins I magnitude
60- 65 F6.4 mag e_Icmag Error in Ic magnitude
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Note (1): North is up, East to the left. 1 pix = 0.369".
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Acknowledgements:
Giovanni Carraro, giovanni.carraro(at)unipd.it
(End) Giovanni Carraro [Padova, Italy], Patricia Vannier [CDS] 25-Jan-2007