Metal abundances of red clump stars in open clusters.: I.: NGC 68191

被引：165

作者：

Bragaglia, A

Carretta, E

Gratton, RG

Tosi, M

Bonanno, G

Bruno, P

Calì, A

Claudi, R

Cosentino, R

Desidera, S

Farisato, G

Rebeschini, M

Scuderi, S

机构：

[1] Osservatorio Astron Bologna, I-40127 Bologna, Italy

[2] Osservatorio Astron Padova, I-35122 Padua, Italy

[3] Univ Catania, Osservatorio Astrofis Catania, I-95125 Catania, Italy

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

来源：

ASTRONOMICAL JOURNAL | 2001年 / 121卷 / 01期

关键词：

open clusters and associations : individual (NGC 6819); stars : abundances; stars : fundamental parameters; techniques : spectroscopic;

D O I：

10.1086/318042

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present an analysis of high-dispersion spectra (R similar to 40,000) of three red clump stars in the old open cluster NGC 6819. The spectra were obtained with SARG, the high-dispersion spectrograph of the Telescopio Nazionale Galileo. The spectra were analyzed using both equivalent widths measured with an automatic procedure and comparisons with synthetic spectra. NGC 6819 is found to be slightly metal-rich ([Fe/H] = +0.09 +/- 0.03, internal error); there are no previous high-resolution studies to compare. Most element-to-element abundance ratios are close to solar; we find a slight excess of Si and a significant Na overabundance. Our spectra can also be used to derive the interstellar reddening toward the cluster by comparing the observed colors with those expected from line excitation : we derive E(B-V) = 0.14 +/- 0.04, in agreement with the most recent estimate for this cluster.

引用

页码：327 / 336

页数：10

共 21 条

[11] The initial mass function of low-mass stars and brown dwarfs in young clusters [J].