THE AGES OF THE DISK CLUSTERS NGC-188, M67, AND NGC-752, USING IMPROVED OPACITIES AND CLUSTER MEMBERSHIP DATA

被引:72
作者
DINESCU, DI
DEMARQUE, P
GUENTHER, DB
PINSONNEAULT, MH
机构
[1] YALE UNIV,CTR SOLAR & SPACE RES,NEW HAVEN,CT 06520
[2] ST MARYS UNIV,DEPT PHYS & ASTRON,HALIFAX,NS B3H 3C3,CANADA
[3] OHIO STATE UNIV,DEPT ASTRON,COLUMBUS,OH 43210
关键词
D O I
10.1086/117434
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Theoretical isochrones have been constructed using the OPAL opacities to derive the ages of the open clusters NGC 188, M67, and NGC 752 as well as to estimate the amount of convective overshoot at the convective core edge. We find that - under the assumptions made in the models - no overshoot, or a very small amount (up to 0.1 Hp) is allowed for the best fits. Very good agreement is achieved between models and the main sequence, turnoff, subgiant, and giant branch for the clusters NGC 188 and M67. For NGC 188 and M67 we derive the ages: 6.0-0.5+1.0 Gyr and 4.0±0.5 Gyr, respectively, where the main uncertainty is due to the estimate of the interstellar reddening. The age of NGC 752 is 2.0-0.3+0.5 Gyr if the adopted metallicity is [Fe/H]=-0.27.
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页码:2090 / 2095
页数:6
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