On the metallicity and the turnoff age of NGC 188

The model atmospheres of Kurucz (1979) are used to analyze the high- dispersion echelle spectra of seven stars located within the turnoff region of NGC 188. This approach yields Fe/H = -0.12 + or - 0.16 and effective temperatures of the turnoff stars of 5885 + or - 120 K. A turnoff age of 7.7 + or -...

Full description

Saved in:
Bibliographic Details
Published in:The Astronomical journal 1990-09, Vol.100, p.710-718
Main Authors: Hobbs, L. M., Thorburn, J. A., Rodriguez-Bell, Theodore
Format: Article
Language:English
Subjects:
640102 - Astrophysics & Cosmology- Stars & Quasi-Stellar, Radio & X-Ray Sources
ABUNDANCE
AGE ESTIMATION
CHEMICAL COMPOSITION
CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
DIAGRAMS
ELEMENT ABUNDANCE
ELEMENTS
HERTZSPRUNG-RUSSELL DIAGRAM
IRON
LUMINOSITY
MATHEMATICAL MODELS
METALS
OPTICAL PROPERTIES
OSCILLATOR STRENGTHS
PHYSICAL PROPERTIES
STAR CLUSTERS
STAR EVOLUTION
STAR MODELS
TRANSITION ELEMENTS
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The model atmospheres of Kurucz (1979) are used to analyze the high- dispersion echelle spectra of seven stars located within the turnoff region of NGC 188. This approach yields Fe/H = -0.12 + or - 0.16 and effective temperatures of the turnoff stars of 5885 + or - 120 K. A turnoff age of 7.7 + or - 1.4 Gyr is then derived by comparing the deduced upper limit on the turnoff temperatures with the appropriate isochrones in the theoretical H-R diagram. These conclusions are effectively independent of the values assumed for the reddening, the intrinsic colors, and the distances of the cluster stars, with their associated uncertainties. (V.L.)
ISSN:0004-6256
1538-3881
DOI:10.1086/115553