uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Exposed bright features on the comet 67P/Churyumov-Gerasimenko: distribution and evolution
Univ Paris 06, Sorbonne Univ, Univ Paris Diderot,LESIA,CNRS, Sorbonne Paris Cite,PSL Res Univ,Observ Paris, 5 Pl Jules Janssen, F-92195 Meudon, France.
Univ Paris 06, Sorbonne Univ, Univ Paris Diderot,LESIA,CNRS, Sorbonne Paris Cite,PSL Res Univ,Observ Paris, 5 Pl Jules Janssen, F-92195 Meudon, France.
Univ Paris 06, Sorbonne Univ, Univ Paris Diderot,LESIA,CNRS, Sorbonne Paris Cite,PSL Res Univ,Observ Paris, 5 Pl Jules Janssen, F-92195 Meudon, France.
Univ Paris 06, Sorbonne Univ, Univ Paris Diderot,LESIA,CNRS, Sorbonne Paris Cite,PSL Res Univ,Observ Paris, 5 Pl Jules Janssen, F-92195 Meudon, France.
Show others and affiliations
2018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 613, article id A36Article in journal (Refereed) Published
Abstract [en]

Context. Since its arrival at the comet 67P/Churyumov-Gerasimenko in August 2014, the Rosetta spacecraft followed the comet as it went past the perihelion and beyond until September 2016. During this time there were many scientific instruments operating on board Rosetta to study the comet and its evolution in unprecedented detail. In this context, our study focusses on the distribution and evolution of exposed bright features that have been observed by OSIRIS, which is the scientific imaging instrument aboard Rosetta. Aims. We envisage investigating various morphologies of exposed bright features and the mechanisms that triggered their appearance. Methods. We co-registered multi-filter observations of OSIRIS images that are available in reflectance. The Lommel-Seeliger disk function was used to correct for the illumination conditions and the resulting colour cubes were used to perform spectrophotometric analyses on regions of interest. Results. We present a catalogue of 57 exposed bright features observed on the nucleus of the comet, all of which are attributed to the presence of H2O ice on the comet. Furthermore, we categorise these patches under four different morphologies and present geometric albedos for each category. Conclusions. Although the nucleus of 67P/Churyumov-Gerasimenko appears to be dark in general, there are localised H2O ice sources on the comet. Cometary activity escalates towards the perihelion passage and reveals such volatile ices. We propose that isolated H2O ice patches found in smooth terrains in regions, such as Imhotep, Bes, and Hapi, result from frost as an aftermath of the cessation of the diurnal water cycle on the comet as it recedes from perihelion. Upon the comet's return to perihelion, such patches are revealed when sublimation-driven erosion removes the thin dust layers that got deposited earlier. More powerful activity sources such as cometary outbursts are capable of revealing much fresher, less contaminated H2O ice that is preserved with consolidated cometary material, as observed on exposed patches resting on boulders. This is corroborated by our albedo calculations that attribute higher albedos for bright features with formations related to outbursts.

Place, publisher, year, edition, pages
2018. Vol. 613, article id A36
Keywords [en]
comets: individual: 67P/Churyumov-Gerasimenko, techniques: photometric, methods: data analysis
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:uu:diva-357562DOI: 10.1051/0004-6361/201732112ISI: 000433276000005OAI: oai:DiVA.org:uu-357562DiVA, id: diva2:1239943
Funder
Swedish National Space BoardAvailable from: 2018-08-20 Created: 2018-08-20 Last updated: 2018-08-20Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Rickman, Hans

Search in DiVA

By author/editor
Rickman, Hans
By organisation
Observational Astronomy
In the same journal
Astronomy and Astrophysics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 4 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf