Comets are relics of the early solar system – conglomerates of ice and dust that have been preserved at cryogenic temperatures with minimal processing. Emission from <b>volatiles</b> - H2O, CO, CO2 – and their fragments is readily observed from the ultraviolet to the infrared. The presence of metal vapors around comets is historically associated with extreme heating, such as for sungrazing comets or impacts on Jupiter. We located emissions from atomic nickel and iron in spectra of comet Hyakutake’s close-approach to Earth in 1996. The identifications are confirmed by comparisons to spectral measurements of a nickel-bearing plasma and a newly developed solar fluorescence model. Using these methods, we recover a non-solar Ni/Fe ratio, begging the question: where did the nickel and iron come from? Temperatures at one to several astronomical units are not sufficient for direct sublimation, and the Ni/Fe abundance suggests a source separate from the bulk composition. I will summarize the fortunate series of events that led us to this work, and motivate organometallics as the possible progenitors of these metal atoms in cometary comae.

Hints at heavy organometallics in cometary comae: The surprising appearance of atomic nickel and iron

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.