Open AccessWhat Does It Mean to be a “Depleted” Comet? High Spectral Resolution Observations of the Prototypical Depleted Comet 21P/Giacobini–Zinner from the McDonald Observatory
Author(s) -
A. L. Cochran,
Tyler Nelson,
Adam McKay
Publication year - 2020
Publication title -
the planetary science journal
Language(s) - English
Resource type - Journals
ISSN - 2632-3338
DOI - 10.3847/psj/abb471
Subject(s) - comet , spectrograph , observatory , physics , astronomy , spectral resolution , comet tail , telescope , astrophysics , spectral line , plasma , nuclear physics , solar wind
We present high spectral resolution optical observations of comet 21P/Giacobini–Zinner from six nights in 2018. The observations were obtained with the Tull Coudé Spectrograph on the 2.7 m Harlan J. Smith Telescope of the McDonald Observatory. This comet’s spectrum shows strong depletions in C 2 , C 3 , CH, and NH 2 relative to CN. We explore what it means for a comet to be depleted and show that all of the species are present in the spectrum at similar relative line intensities within a a molecular band compared with a typical comet. The depletions represent a much lower abundance of the species studied.