Analysis of the far ultraviolet silicon lines in G dwarf stars

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The structure of the outer stellar regions is investigated for four G type dwarfs observed with the IUE satellite. Line fluxes of the Si II lines at 1817 Å, 1808 A, and 1309 Å and Si III at 1206 Å are used to obtain temperatures and electronic densities. A temperature of 16,000 K is found from the lines at 1817 Å and 1808 Å, 26,000 K from the 1309 A line and 50,000 K from that at 1206 A. Predicted fluxes are compared with the observed ones. The significance of the results is discussed in terms of line formation regions.
© European Southern Observatory. © EDP Sciencies. We are grateful to Drs. M. Penston and A. Heck, VILPSA assistant astronomers, for help during the course of observations and also to the VILPSA team responsible for training and data reduction.
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