J/A+A/381/65 BVI photometry of NGC 2099 (Nilakshi+, 2002)
A comprehensive study of the rich open star cluster NGC 2099 based on
deep BVI CCD observations
Nilakshi N., Sagar R.
<Astron. Astrophys. 381, 65 (2002)>
=2002A&A...381...65N 2002A&A...381...65N
ADC_Keywords: Clusters, open ; Photometry, CCD
Keywords: open clusters and associations: individual: NGC 2099 -
stars: HR diagram - evolution - formation
Abstract:
The CCD observations of the rich open star cluster NGC 2099 and its
surrounding field region have been carried out up to a limiting
magnitude of V∼22mag in B, V and I passbands for the first time. A
total of ∼12000 stars have been observed in the area of about 24'x24'
in the cluster region, as well as ∼2180 stars in the ∼ 12'x12' area of
the field region located ∼45' away from the cluster center. The
cluster parameters determined by fitting the convective core overshoot
isochrones in the V, (B-V) and V, (V-I) diagrams are
E(B-V)=0.30±0.40mag, distance=1360±100pc, age=400Myr and
metallicity Z=0.008.
Objects:
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RA (2000) DE Designation(s)
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05 52 17.6 +32 32 40 NGC 2099
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 74 14103 Relative positions and BVI magnitudes in NGC 2099
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- Region [CF] Cluster (C) or Field (F) region
3- 8 I6 --- Star Sequential star number
12- 18 F7.2 pix Xpos X position (1)
21- 27 F7.2 pix Ypos Y position (1)
30- 34 F5.2 mag Vmag V magnitude
37- 41 F5.2 mag B-V ? B-V colour index
44- 48 F5.2 mag V-I ? V-I colour index
52- 55 F4.2 mag e_Imag ? DAOPHOT error in I passband
59- 62 F4.2 mag e_Vmag DAOPHOT error in V passband
66- 69 F4.2 mag e_Bmag ? DAOPHOT error in B passband
73- 74 A2 --- Memb Membership proper motion (KM) and
photometric (PM) membership
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Note (1): The X and Y coordinates are accurate up to 0.5 pixel.
The coordinates of the cluster center are
RA = 05h 52m 17.6s, DE = +32° 32' 40"
X values increase towards West while Y values increase towards south.
One pixel along X and Y corresponds to 0.74 arcsec. Entire field
corresponds to about 24 arcmin along X-axis and about 34 arcmin along
Y axis.
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Acknowledgements: Ram Sagar
(End) Patricia Bauer [CDS] 23-Nov-2001