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Discovery of Enhanced Germanium Abundances in Planetary Nebulae with FUSE

N. C. Sterling·H. L. Dinerstein·C. W. Bowers
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Abstract

We report the discovery of Ge III $λ$1088.46 in the planetary nebulae (PNe) SwSt 1, BD+30$^{\rm o}$3639, NGC 3132, and IC 4593, observed with the Far Ultraviolet Spectroscopic Explorer. This is the first astronomical detection of this line and the first measurement of Ge (Z = 32) in PNe. We estimate Ge abundances using S and Fe as reference elements, for a range of assumptions about gas-phase depletions. The results indicate that Ge, which is synthesized in the initial steps of the s-process and therefore can be self-enriched in PNe, is enhanced by factors of > 3-10. The strongest evidence for enrichment is seen for PNe with Wolf-Rayet central stars, which are likely to contain heavily processed material.

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N. C. Sterling, H. L. Dinerstein, C. W. Bowers. 2002-08-28. Discovery of Enhanced Germanium Abundances in Planetary Nebulae with FUSE. https://doi.org/10.1086/344473

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