Magellanic Clouds Cepheids: Thorium Abundances

Yeuncheol Jeong, Alexander V. Yushchenko, Vira F. Gopka, Volodymyr O. Yushchenko, Valery V. Kovtyukh, Svetlana V. Vasil'eva
2018 Journal of Astronomy and Space Sciences  
The analysis of the high-resolution spectra of 31 Magellanic Clouds Cepheid variables enabled the identification of thorium lines. The abundances of thorium were found with spectrum synthesis method. The calculated thorium abundances exhibit correlations with the abundances of other chemical elements and atmospheric parameters of the program stars. These correlations are similar for both Clouds. The correlations of iron abundances of thorium, europium, neodymium, and yttrium relative to the
more » ... relative to the pulsational periods are different in the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), namely the correlations are negative for LMC and positive or close to zero for SMC. One of the possible explanations can be the higher activity of nucleosynthesis in SMC with respect to LMC in the recent several hundred million years.
doi:10.5140/JASS.2017.35.1.19 doaj:1964978ac7c943729a83d6806c59f6c1 fatcat:zhknwa62cfarrblgrmzwr72l44