Abundances of Elements in Stars and Nebulae (The Manganese Star 53 Tauri)

摘要

The chemical composition of the Manganese star 53 Tauri was studied with the aid of data secured with the coude spectrograph of the 120-inch reflector at the Lick Observatory. Transition probabilities required for the problem are obtained from laboratory sources whenever possible, but some are obtained by the calibration of stellar data. The temperature of the star, deduced from ionization equilibrium, is near 11,000K-a value in good agreement with that found from spectral energy scans by Jugaku and Sargent. The electron pressure in the atmosphere, deduced from the total intensities of hydrogen lines, appears to lie in the neighborhood of 500 dynes sq cm. Several striking abundance anomalies are found; they cannot be explained by deviations from local thermodynamic equilibrium. Manganese seems to be the most abundant metal in the star, but gallium appears to show the greatest enhancement of abudance over the 'normal' value. Strontium, yttrium, and zirconium are also enhanced in abudnace, whilst magnesium, and calcium seems to be depleted. (Author)