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| Titel |
New HST observations of Ceres in the search for exospheric emissions |
| VerfasserIn |
Lorenz Roth, Nickolay Ivchenko, Kurt Retherford, Nathaniel Cunningham, Paul Feldman, Joachim Saur, John Spencer, Darrell Strobel |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125036
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| Publikation (Nr.) |
 EGU/EGU2016-4559.pdf |
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| Zusammenfassung |
| In August 2015, we obtained far-ultraviolet observations of Ceres to search for atomic
emissions from an exosphere using the Cosmic Origins Spectrograph (COS) on the Hubble
Space Telescope (HST). We derive brightnesses at the oxygen multiplets at 1304 Å and 1356
Å and relate them to the abundance of atomic oxygen (O). Assuming that O is produced by
photodissociation of H2O, an upper limit for H2O abundance is derived and compared to
previous observations and models. While our results are consistent with a tenuous
sublimated H2O exosphere, they suggest that high H2O production with a rate of 1026
molecules/s as previously inferred was not present during the observation. The
results of our observation provide valuable supplementary information on Ceres’ gas
environment during the high altitude mapping orbit phase of NASA’s Dawn mission. |
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