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J/ApJ/298/544        NGC 121 BR photometry (Stryker+ 1985)

The main-sequence turnoff of the old SMC globular cluster NGC 121 Stryker L.L., Da Costa G.S., Mould J.R. <Astrophys. J. 298, 544 (1985)> =1985ApJ...298..544S (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Clusters, globular ; Photometry, CCD Keywords: clusters: globular - galaxies: Magellanic Clouds - stars: abundances - stars: evolution Abstract: The age of the SMC globular cluster NGC 121 is found from main-sequence isochrone fitting to be 12±2x109yr if a distance modulus that assumes Mv=+0.6 for the field RR Lyrae variables near the cluster is used. If instead (m-M)o = 19.3, then the cluster age is 9±2x109yr. The cluster is known to contain both RR Lyrae variables and a marginal carbon star; comparison with theoretical models indicates no significant inconsistencies in this joint occurrence at either modulus. The color-magnitude diagram for the nearby field also shows a faint, blue main-sequence turnoff and, in contrast to previous Magellanic Cloud field studies, the field lacks any evidence for the existence of a significant intermediate-age component. A new look at the chemical evolution of the Small Magellanic Cloud suggests that, unlike the Galaxy, where the rate of enrichment has been steady after the initial phase, the enrichment in the SMC remained small for a long interval before increasing rapidly sometime in the last 1-2x109yr. Objects: ----------------------------------------- RA (2000) DE Designation(s) ----------------------------------------- 00 26.7 -71 31 NGC 121 ----------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1 40 242 Photometry in NGC 121 table2 42 300 Photometry in field
Byte-by-byte Description of file: table1 table2
Bytes Format Units Label Explanations
1- 3 I3 --- Star Star identification number 5- 8 F4.2 mag B-R B-R color index 10- 14 F5.2 mag Rmag R magnitude 16- 21 F6.2 pix Xpos X position (1) 23- 28 F6.2 pix Ypos Y position (1) 30- 34 F5.2 mag DB-R ? November 18-20 B-R color index difference 36- 40 F5.2 mag DRmag ? November 18-20 R magnitude difference
Note (1): Origin: southwest corner of fig. 1
History: Prepared via OCR at CDS.
(End) Marie-Jose Wagner, Patricia Bauer [CDS] 30-Sep-1996
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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