An abundance analysis of the symbiotic star CH Cyg

Abstract

The photospheric abundances for the cool component of the symbiotic star CH Cyg were calculated for the first time using high-resolution near-infrared spectra and the method of of standard LTE analysis and atmospheric models. The iron abundance for CH Cyg was found to be solar, [Fe/H] = 0.0+/-0.19. The atmospheric parameters and metallicity for CH Cyg are found to be approximately equal to those for nearby field M7 giants. The calculated [C/H] = -0.15, [N/H] = +0.16, [O/H] = -0.07, and the isotopic ratios of 12C/13C and 16O/17O are close to the mean values for single M giants that have experienced the first dredge-up. A reasonable explanation for the absence of barium star-like chemical peculiarities seems to be the high metallicity of CH Cyg. The emission line technique was explored for estimating CNO ratios in the wind of the giant.

arXiv comment9 pages, 4 figures, 4 tables; accepted for publication in A&A

References in corpus (5)

• The NextGen Model Atmosphere grid: II. Spherically symmetric model atmospheres for giant stars with effective temperatures between 3000 and 6800~K
• Self-similarity and scaling behavior of IR emission from radiatively heated dust: I. Theory
• Oscillator Strengths and Damping Constants for Atomic Lines in the J and H Bands
• Synthetic Spectra and Color-Temperature Relations of M Giants
• The Stellar Parameters and Evolutionary State of the Primary in the d'-Symbiotic System StH\alpha190

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