FUV Observations of the Inner Coma of 46P/Wirtanen

Far-ultraviolet observations of comets yield information about the energetic processes that dissociate the sublimated gases from their primitive surfaces. Understanding which emission processes are dominant, their effects on the observed cometary spectrum, and how to properly invert the spectrum bac...

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Main Authors: John W. Noonan, Walter M. Harris, Steven Bromley, Davide Farnocchia, Jian-Yang Li, Kathleen E. Mandt, Joel Wm. Parker, Kumar Venkataramani, Dennis Bodewits
Format: Article
Language:English
Published: IOP Publishing 2021-01-01
Series:The Planetary Science Journal
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Online Access:https://doi.org/10.3847/PSJ/abd038
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author John W. Noonan
Walter M. Harris
Steven Bromley
Davide Farnocchia
Jian-Yang Li
Kathleen E. Mandt
Joel Wm. Parker
Kumar Venkataramani
Dennis Bodewits
author_facet John W. Noonan
Walter M. Harris
Steven Bromley
Davide Farnocchia
Jian-Yang Li
Kathleen E. Mandt
Joel Wm. Parker
Kumar Venkataramani
Dennis Bodewits
author_sort John W. Noonan
collection DOAJ
description Far-ultraviolet observations of comets yield information about the energetic processes that dissociate the sublimated gases from their primitive surfaces. Understanding which emission processes are dominant, their effects on the observed cometary spectrum, and how to properly invert the spectrum back to the composition of the presumably pristine surface ices of a comet nuclei are all critical components for proper interpretation and analysis of comets. The close approach of comet 46P/Wirtanen in 2018–2019 provided a unique opportunity to study the innermost parts of a cometary coma with the Hubble Space Telescope Cosmic Origins Spectrograph, rarely accessible with remote observations, at length scales (hundreds of kilometers) and wavelengths (900–1430 Å) previously probed only by the European Space Agency’s Rosetta spacecraft. Our observations show a complex picture for the inner coma; atomic production rates for H and O that show water is the dominant source of both, an abundance of atomic sulfur that is difficult to explain with the lifetimes of common sulfur parent molecules, and a density distribution that is poorly fit with both Haser and vectorial models.
format Article
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issn 2632-3338
language English
publishDate 2021-01-01
publisher IOP Publishing
record_format Article
series The Planetary Science Journal
spelling doaj-art-6042cd85229f4d9ba081effd0acaa0322025-08-20T02:12:20ZengIOP PublishingThe Planetary Science Journal2632-33382021-01-0121810.3847/PSJ/abd038FUV Observations of the Inner Coma of 46P/WirtanenJohn W. Noonan0https://orcid.org/0000-0003-2152-6987Walter M. Harris1https://orcid.org/0000-0002-8378-4503Steven Bromley2https://orcid.org/0000-0003-2110-8152Davide Farnocchia3https://orcid.org/0000-0003-0774-884XJian-Yang Li4https://orcid.org/0000-0003-3841-9977Kathleen E. Mandt5https://orcid.org/0000-0001-8397-3315Joel Wm. Parker6https://orcid.org/0000-0002-3672-0603Kumar Venkataramani7https://orcid.org/0000-0003-3321-1472Dennis Bodewits8https://orcid.org/0000-0002-2668-7248Lunar and Planetary Laboratory, University of Arizona , 1629 E University Boulevard, Tucson, AZ 85721-0092, USA ; noonan@lpl.arizona.eduLunar and Planetary Laboratory, University of Arizona , 1629 E University Boulevard, Tucson, AZ 85721-0092, USA ; noonan@lpl.arizona.eduPhysics Department, Leach Science Center, Auburn University , Auburn, AL 36882, USAJet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USAPlanetary Science Institute , 1700 E. Ft. Lowell Road, Suite 106, Tucson, AZ 85719, USAJohns Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Road, Laurel, MD 20723, USAPlanetary Science Directorate, Southwest Research Institute , Suite 300, 1050 Walnut Street, Boulder, CO 80302, USAPhysics Department, Leach Science Center, Auburn University , Auburn, AL 36882, USAPhysics Department, Leach Science Center, Auburn University , Auburn, AL 36882, USAFar-ultraviolet observations of comets yield information about the energetic processes that dissociate the sublimated gases from their primitive surfaces. Understanding which emission processes are dominant, their effects on the observed cometary spectrum, and how to properly invert the spectrum back to the composition of the presumably pristine surface ices of a comet nuclei are all critical components for proper interpretation and analysis of comets. The close approach of comet 46P/Wirtanen in 2018–2019 provided a unique opportunity to study the innermost parts of a cometary coma with the Hubble Space Telescope Cosmic Origins Spectrograph, rarely accessible with remote observations, at length scales (hundreds of kilometers) and wavelengths (900–1430 Å) previously probed only by the European Space Agency’s Rosetta spacecraft. Our observations show a complex picture for the inner coma; atomic production rates for H and O that show water is the dominant source of both, an abundance of atomic sulfur that is difficult to explain with the lifetimes of common sulfur parent molecules, and a density distribution that is poorly fit with both Haser and vectorial models.https://doi.org/10.3847/PSJ/abd038Short period cometsAtomic spectroscopyUltraviolet astronomy
spellingShingle John W. Noonan
Walter M. Harris
Steven Bromley
Davide Farnocchia
Jian-Yang Li
Kathleen E. Mandt
Joel Wm. Parker
Kumar Venkataramani
Dennis Bodewits
FUV Observations of the Inner Coma of 46P/Wirtanen
The Planetary Science Journal
Short period comets
Atomic spectroscopy
Ultraviolet astronomy
title FUV Observations of the Inner Coma of 46P/Wirtanen
title_full FUV Observations of the Inner Coma of 46P/Wirtanen
title_fullStr FUV Observations of the Inner Coma of 46P/Wirtanen
title_full_unstemmed FUV Observations of the Inner Coma of 46P/Wirtanen
title_short FUV Observations of the Inner Coma of 46P/Wirtanen
title_sort fuv observations of the inner coma of 46p wirtanen
topic Short period comets
Atomic spectroscopy
Ultraviolet astronomy
url https://doi.org/10.3847/PSJ/abd038
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