Diurnal variation of dust and gas production in comet 67P/Churyumov-Gerasimenko at the inbound equinox as seen by OSIRIS and VIRTIS-M on board Rosetta
Barucci, M. A.
Capria, M. T.
Da Deppo, V.
De Cecco, M.
De Sanctis, M. C.
Gutiérrez, P. J.
Keller, H. U.
La Forgia, F.
Lamy, P. L.
Lara, L. M.
Levasseur-Regourd, A. C.
López-Moreno, J. J.
AffiliationUniv Arizona, Lunar & Planetary Lab
MetadataShow full item record
PublisherEDP SCIENCES S A
CitationTubiana, Rinaldi, Güttler, Snodgrass, Shi, Hu, . . . Bockelée-Morvan. (2019). Diurnal variation of dust and gas production in comet 67P/Churyumov-Gerasimenko at the inbound equinox as seen by OSIRIS and VIRTIS-M on board Rosetta. Astronomy & Astrophysics, 630, A23.
JournalASTRONOMY & ASTROPHYSICS
RightsCopyright © C. Tubiana et al. 2019. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractContext. On 27 April 2015, when comet 67P/Churyumov-Gerasimenko was at 1.76 au from the Sun and moving toward perihelion, the OSIRIS and VIRTIS-M instruments on board the Rosetta spacecraft simultaneously observed the evolving dust and gas coma during a complete rotation of the comet. Aims. We aim to characterize the spatial distribution of dust, H2O, and CO2 gas in the inner coma. To do this, we performed a quantitative analysis of the release of dust and gas and compared the observed H2O production rate with the rate we calculated using a thermophysical model. Methods. For this study we selected OSIRIS WAC images at 612 nm (dust) and VIRTIS-M image cubes at 612 nm, 2700 nm (H2O emission band), and 4200 nm (CO2 emission band). We measured the average signal in a circular annulus to study the spatial variation around the comet, and in a sector of the annulus to study temporal variation in the sunward direction with comet rotation, both at a fixed distance of 3.1 km from the comet center. Results. The spatial correlation between dust and water, both coming from the sunlit side of the comet, shows that water is the main driver of dust activity in this time period. The spatial distribution of CO2 is not correlated with water and dust. There is no strong temporal correlation between the dust brightness and water production rate as the comet rotates. The dust brightness shows a peak at 0 degrees subsolar longitude, which is not pronounced in the water production. At the same epoch, there is also a maximum in CO2 production. An excess of measured water production with respect to the value calculated using a simple thermophysical model is observed when the head lobe and regions of the southern hemisphere with strong seasonal variations are illuminated (subsolar longitude 270 degrees-50 degrees). A drastic decrease in dust production when the water production (both measured and from the model) displays a maximum occurs when typical northern consolidated regions are illuminated and the southern hemisphere regions with strong seasonal variations are instead in shadow (subsolar longitude 50 degrees-90 degrees). Possible explanations of these observations are presented and discussed.
NoteOpen access journal
VersionFinal published version
SponsorsGermany (DLR)Helmholtz AssociationGerman Aerospace Centre (DLR); France (CNES)Centre National D'etudes Spatiales; Italy (ASI)Italian Space Agency; Spain (MEC)Ministry of Education and Science, Spain; Sweden (SNSB); ESA Technical Directorate; ASIItalian Space Agency; Observatoire de Meudon - CNES; DLRHelmholtz AssociationGerman Aerospace Centre (DLR); Italian Space Agency (ASI, Italy) [I/024/12/1]; Centre National d'Etudes Spatiales (CNES, France)Centre National D'etudes Spatiales; DLR (Germany)Helmholtz AssociationGerman Aerospace Centre (DLR); NASA (USA) Rosetta Program; Science and Technology Facilities Council (UK)Science & Technology Facilities Council (STFC)