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J/AJ/134/229  CT1T2 Photometry of red giants in 2 globulars (Hughes+, 2007)

Washington photometry of the red giant branch in NGC 6388. Hughes J., Wallerstein G., Covarrubias R., Hays N. <Astron. J., 134, 229-240 (2007)> =2007AJ....134..229H
ADC_Keywords: Clusters, globular ; Stars, giant ; Photometry, CMT1T2V Keywords: globular clusters: general - globular clusters: individual (47 Tucanae, NGC 6388) Abstract: We present Washington photometry of the giant branches of the relatively metal-rich globular cluster NGC 6388 and compare it with 47 Tuc. By examining the spatial distribution of stellar colors across the red giant branch and using spectroscopic data on several bright giants, we found that NGC 6388's center is affected by differential reddening of at least {DELTA}E(B-V)∼0.1. Most of the width of the red giant branch is caused by that differential reddening. The southeastern outer regions of the cluster seem to be less affected by variable dust extinction, and we find that NGC 6388 is slightly more metal-rich than 47 Tuc, with a distinct asymptotic giant branch. We have put an upper limit on possible variations in [Fe/H] for NGC 6388, finding that it must be less than ∼0.2dex. It is unlikely that such a small range in metallicity could be responsible for the blue horizontal branch and blue tail stars in a cluster with a metallicity similar to the more massive 47 Tuc, which only exhibits a red horizontal branch. Description: We observed NGC 6388 with the CTIO 0.9m telescope, the Tek 2048 No. 3 chip, and Arcon 3.3. This paper uses images obtained on 2003 May 23, because this night had the best seeing over the observing run (∼1.0"). Specifically, we used 21 frames taken with Washington C and Cousins R and I filters, with exposure time ranging from 20 to 900s. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 17 36 17.1 -44 44 06 NGC 6388 = C 1732-447 13 26 45.9 -47 28 37 NGC 5139 = C 1323-472 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 62 17666 Original sample of objects in NGC 6388 table3.dat 62 5473 Sample of objects in 47 Tuc
Byte-by-byte Description of file: table2.dat table3.dat
Bytes Format Units Label Explanations
1- 5 I5 --- Seq Object identification (1) 7- 14 F8.3 pix Xpos X pixel coordinate (2) 16- 23 F8.3 pix Ypos Y pixel coordinate (2) 25- 30 F6.3 mag T1mag Washington T1 magnitude (633nm) 32- 36 F5.3 mag e_T1mag 1σ error in T1mag 38- 43 F6.3 mag C-T1 Washington (C-T1) color index (391-633nm) 45- 49 F5.3 mag e_C-T1 1σ error in C-T1 51- 56 F6.3 mag T1-T2 Washington (T1-T2) color index (633-788nm) 58- 62 F5.3 mag e_T1-T2 1σ error in T1-T2
Note (1): Objects identified as: Cl* NGC 6388 HWC NNNNN in table2, Cl* NGC 5139 HWC NNN in table3 in Simbad Note (2): 1pix=0.396". North is down and east is to the left.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 23-Aug-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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