Abundances in the red giants of M13 and M22
- Maryland Univ., College Park (USA) Palomar Observatory, Pasadena, CA (USA)
Abundances of Ca, Na, and Fe are derived for 10 red giant branch stars in the globular clusters M13 and M22, by means of model atmosphere analyses of high-dispersion spectra. It was found that M13 and M22 represent two different types of globular clusters. M13 is similar to M92 and many other globular clusters in that it displays variations in CH and CN band strengths, while showing no variation in either Ca or Fe abundance. The Na abundance was found to vary and its variation correlates with CN band strengths. This suggests that the source of the observed CN band strength variation is the same as that of the Na variation. M22, on the other hand, is similar to Omega Cen, in that it displays variations in Ca, Na, and Fe abundances, and these variations correlate with variations in CH and CN band strengths. These correlations suggest that the cause of the variations in M22 is largely primordial, and that mixing may only make a relatively small contribution to the C and N variations observed. 61 refs.
- OSTI ID:
- 6002602
- Journal Information:
- Astrophysical Journal; (USA), Vol. 367; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
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Related Subjects
GENERAL PHYSICS
RED GIANT STARS
CHEMICAL COMPOSITION
STAR CLUSTERS
CALCIUM
CYANOGEN
ELEMENT ABUNDANCE
IRON
MIXING
SODIUM
STAR MODELS
STELLAR ATMOSPHERES
VARIATIONS
ABUNDANCE
ALKALI METALS
ALKALINE EARTH METALS
ATMOSPHERES
ELEMENTS
GIANT STARS
MATHEMATICAL MODELS
METALS
STARS
TRANSITION ELEMENTS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
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