A triple main sequence in the globular cluster NGC 2808

被引：566

作者：

Piotto, G.

Bedin, L. R.

Anderson, J.

King, I. R.

Cassisi, S.

Milone, A. P.

Villanova, S.

Pietrinferni, A.

Renzini, A.

机构：

[1] Univ Padua, Dipartimento Astron, I-35122 Padua, Italy

[2] European So Observ, D-85748 Garching, Germany

[3] Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA

[4] Univ Washington, Dept Astron, Seattle, WA 98195 USA

[5] Osservatorio Astron Collurania, INAF, I-64100 Teramo, Italy

[6] Osserv Astron Padova, INAF, I-35122 Padua, Italy

来源：

ASTROPHYSICAL JOURNAL | 2007年 / 661卷 / 01期

关键词：

globular clusters : individual (NGC 2808); Hertzsprung-Russell diagram;

D O I：

10.1086/518503

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Accurate photometry with HST's ACS shows that the main sequence ( MS) of the globular cluster NGC 2808 splits into three separate branches. The three MS branches may be associated with the complexities of the cluster's horizontal branch and of its abundance distribution. We attribute the MS branches to successive rounds of star formation, with different helium abundances; we discuss possible sources of helium enrichment. Some other massive globulars also appear to have complex populations; we compare them with NGC 2808.

引用

页码：L53 / L56

页数：4

共 29 条

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ANDERSON J, 2006, ACS ISR 2006

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