PHOTOMETRY OF THE OUTER HALO GLOBULAR-CLUSTERS NGC 5024 AND NGC 5053

被引:22
作者
HEASLEY, JN
CHRISTIAN, CA
机构
[1] UNIV HAWAII,INST ASTRON,HONOLULU,HI 96822
[2] UNIV CALIF BERKELEY,CTR EUVE ASTROPHYS,EUVE PROJECT,BERKELEY,CA 94720
关键词
D O I
10.1086/115740
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
New CCD photometry of the low-metallicity outer halo globular clusters NGC 5024 and NGC 5053 is used to construct BV color-magnitude diagrams that reach approximately 2 mag fainter than the turnoff in these clusters. A differential comparison of the color-magnitude diagrams with that of M92 indicates all three clusters are identical in age to within the uncertainties of the observations. With the addition of these two clusters, color-magnitude diagrams are now available for more than half of the globular clusters with [Fe/H] < - 2.0, and with the exception of Ruprecht 106, no discernible spread in age among these clusters is detected.
引用
收藏
页码:967 / 979
页数:13
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