J/MNRAS/437/1241 Be 81, NGC 1917 and NGC 2141 BVI photometry (Donati+, 2014)
NGC 1817, NGC 2141 and Berkeley 81: three BOCCE clusters of intermediate age.
Donati P., Beccari G., Bragaglia A., Cignoni M., Tosi M.
<Mon. Not. R. Astron. Soc., 437, 1241-1258 (2014)>
=2014MNRAS.437.1241D 2014MNRAS.437.1241D (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Photometry, UBVRI
Keywords: Hertzsprung-Russell and colour-magnitude diagrams - Galaxy: disc -
open clusters and associations: general -
open clusters and associations: individual: Berkeley 81 -
open clusters and associations: individual: NGC 1817 -
open clusters and associations: individual: NGC 2141 -
Abstract:
In this paper we analyse the evolutionary status of three open
clusters: NGC 1817, NGC 2141 and Berkeley 81. They are all of
intermediate age, two are located in the Galactic anticentre direction
while the third one is located in the Galactic Centre direction. All
of them were observed with Large Binocular Camera at Large Binocular
Telescope using the Bessel B, V and I filters. The cluster parameters
have been obtained using the synthetic colour-magnitude diagram (CMD)
method, i.e. the direct comparison of the observational CMDs with a
library of synthetic CMDs generated with different evolutionary sets
(Padova, FRANEC and FST). This analysis shows that NGC 1817 has
subsolar metallicity, age between 0.8 and 1.2Gyr, reddening E(B-V)
in the range 0.21 and 0.34 and distance modulus (m-M)0 of about
10.9; NGC 2141 is older, with age in the range 1.25 and 1.9Gyr,
E(B-V) between 0.36 and 0.45, (m-M)0 between 11.95 and 12.21 and
subsolar metallicity; Berkeley 81 has metallicity about solar, with
age between 0.75 and 1.0Gyr, has reddening E(B-V)∼0.90 and distance
modulus (m-M)_0∼12.4. Exploiting the large field of view of the
instrument we derive the structure parameters for NGC 2141 and
Berkeley 81 by fitting a King profile to the estimated density
profile. Combining this information with the synthetic CMD technique
we estimate a lower limit for the cluster total mass for these two
systems.
Description:
Analysis of the evolutionary status and structural properties of three
intermediate-old open clusters of the BOCCE project: Berkeley 81,
NGC 1817, and NGC 2141. For each one of them age, distance modulus,
intergalactic reddening, and approximate photometric metallicity are
estimated. For Berkeley 81 and NGC 2141 the density profile is studied
in terms of a King's model. In the case of NGC 2141 the effect of
differential reddening is quantified.
Objects:
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RA (2000) DE Designation(s) (file)
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19 01 43 -00 27 08 Be 81 = Berkeley 81 (be81bvi.dat)
05 12 38 +16 43 49 NGC 1817 = Cl Collinder 60 (n1817bvi.dat)
06 02 58 +10 27 14 NGC 2141 = Cl Collinder 79 (n2141bvi.dat)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
be81bvi.dat 149 113761 BVI Johnson-Cousins photometric catalogue
for Berkeley 81
n1817bvi.dat 149 6210 BVI Johnson-Cousins photometric catalogue
for NGC 1817
n2141bvi.dat 182 12255 BVI Johnson-Cousins photometric catalogue
for NGC 2141
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See also:
J/MNRAS/299/1 : BVI photometry in four open clusters (Sagar+, 1998)
J/A+A/372/879 : JKBV photometry of NGC 2141 (Carraro+, 2001)
J/A+A/426/827 : ubvyHβ photometry in NGC 1817/1807 (Balaguer-Nunez+ 2005)
Byte-by-byte Description of file: be81bvi.dat n1817bvi.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID Identification number within the cluster
9- 10 A2 --- --- [CH]
11 I1 --- Chip [1/4] Instrumental chip identification
14- 22 F9.4 pix Xpos X chip coordinate
24- 32 F9.4 pix Ypos Y chip coordinate
36- 46 F11.7 deg RAdeg Right ascension (J2000.0)
50- 60 F11.7 deg DEdeg Declination (J2000.0)
65- 72 F8.5 arcmin Dist Distance from the cluster's centre
76- 81 F6.3 mag Bmag ?=99.999 Johnson B magnitude
83- 88 F6.3 mag e_Bmag ?=99.999 Error on magnitude B (G1)
91- 96 F6.3 mag Vmag ?=99.999 Johnson V magnitude
(calibrated from B-V colour)
98-103 F6.3 mag e_Vmag ?=99.999 Error on magnitude V (G1)
105-110 F6.3 mag V2mag ?=99.999 Johnson V magnitude
(calibrated from V-I colour)
112-117 F6.3 mag e_V2mag ?=99.999 Error on magnitude V2 (G1)
120-125 F6.3 mag Imag ?=99.999 Cousins I magnitude
127-132 F6.3 mag e_Imag ?=99.999 Error on magnitude I (G1)
136-141 F6.3 --- ch Average χ2 of the PSF fit (G1)
144-149 F6.3 --- sh Sharpness (G1)
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Byte-by-byte Description of file: n2141bvi.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID Identification number
9- 10 A2 --- --- [CH]
11 I1 --- Chip [1/4] Instrumental chip identification
14- 22 F9.4 pix Xpos X chip coordinate
24- 32 F9.4 pix Ypos Y chip coordinate
36- 46 F11.7 deg RAdeg Right ascension (J2000.0)
50- 60 F11.7 deg DEdeg Declination (J2000.0)
65- 72 F8.5 arcmin Dist Distance from the cluster's centre
77- 82 F6.3 mag Bmag ?=99.999 Johnson B magnitude
85- 90 F6.3 mag e_Bmag ?=99.999 Error on magnitude B (G1)
94- 99 F6.3 mag Vmag ?=99.999 Johnson V magnitude
(calibrated from B-V colour)
102-107 F6.3 mag e_Vmag ?=99.999 Error on magnitude V (G1)
110-115 F6.3 mag V2mag ?=99.999 Johnson V magnitude
(calibrated from V-I colour)
118-123 F6.3 mag e_V2mag ?=99.999 Error on magnitude V2 (G1)
127-132 F6.3 mag Imag ?=99.999 Cousins I magnitude
135-140 F6.3 mag e_Imag ?=99.999 Error on magnitude I (G1)
144-149 F6.3 --- ch Average χ2 of the PSF fit (G1)
152-157 F6.3 --- sh Sharpness (G1)
160-166 F7.3 mag dE(B-V) ?=999 Differential reddening
169-174 F6.3 mag Vmagc ?=99.999 V magnitude corrected for differential
reddening
177-182 F6.3 mag B-Vc ?=0 B-V colour index corrected for differential
reddening
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Global notes:
Note (G1): Errors, ch, and sh are the parameters of Daophot II.
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Acknowledgements:
Paolo Donati, paolo.donati4(at)unibo.it
(End) Paolo Donati [INAF-OABO, Italy], Patricia Vannier [CDS] 04-May-2014