J/AJ/119/1793 NGC 6144 BVI photometry (Neely+, 2000)
CCD photometry of the galactic globular cluster NGC 6144.
Neely R.K., Sarajedini A., Martins D.H.
<Astron. J. 119, 1793 (2000)>
=2000AJ....119.1793N 2000AJ....119.1793N
ADC_Keywords: Clusters, globular ; Photometry, CCD
Keywords: globular clusters: general - stars: AGB and post-AGB -
techniques: photometric
Abstract:
We present CCD photometry in the BVI-filter passbands for the Galactic
globular cluster NGC 6144. This cluster is located in the direction of
the ρ Ophiuchi dust cloud, approximately 30 northwest of the
bright star α Scorpii (Antares). Our color-magnitude diagrams
(CMDs) of NGC 6144 extend from above the tip of the first-ascent red
giant branch (RGB) to ∼3mag below the horizontal branch (HB). The
morphology of the HB is predominantly blueward of the RR Lyrae
instability strip, while the RGB is relatively steep, signifying a
low-to-intermediate metal abundance. Our CMD also reveals the presence
of three candidate post-asymptotic giant branch stars. We find
VHB=16.30±0.07; coupling the measured RGB color at the level of the
HB with a polynomial describing the shape of the RGB, we have utilized
the simultaneous reddening and metallicity method of Sarajedini to
estimate a metallicity of [Fe/H]=-1.81±0.12 (on the Zinn & West,
1984ApJS...55...45Z 1984ApJS...55...45Z, scale) and a mean reddening of
E(B-V)=0.41±0.02. In addition to this mean level, our observations
reveal that the reddening has a spatially variable component generally
increasing from north to south consistent with the expected density
variations in the ρ Ophiuchi dust cloud.
Objects:
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RA (2000) DE Designation(s)
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16 27 14.1 -26 01 29 NGC 6144
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 38 10 NGC 6144 photometry
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- NSM [1/1216] Star number
Cl* NGC 6144 NSM NNNN in Simbad
6- 12 F7.2 pix xpos X position (1)
14- 20 F7.2 pix ypos Y position (1)
22- 26 F5.2 mag Vmag V magnitude
28- 32 F5.2 mag B-V B-V colour index
34- 38 F5.2 mag V-I V-I colour index
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Note (1): North is up, and east is to the left. 1 pix = 0.396"
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Table 2 : PAGB STARS
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Star Vmag (B-V)0 (V-I)_0) NB NV NI
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PAGB 1 11.85±0.02 0.13±0.03 0.25±0.01 5 5 5
PAGB 2 16.74±0.03 -0.32±0.05 -0.23±0.04 3 5 5
PAGB 3 19.30±0.13 -0.34±0.17 -0.23±0.18 5 3 4
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History:
From AJ electronic version
(End) Patricia Bauer [CDS] 15-Jan-2001