2024-03-28T17:20:08Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1462682021-10-27T11:25:12Zcom_10261_97com_10261_4com_10261_44col_10261_350col_10261_297
A mini outburst from the nightside of comet 67P/Churyumov-Gerasimenko observed by the OSIRIS camera on Rosetta
Knollenberg, J.
Rodrigo, R.
Gutiérrez, Pedro J.
Lara, Luisa María
López-Moreno, José Juan
Ministerio de Educación y Ciencia (España)
Comets: general
Methods: numerical
Comets: individual: 67P/Churyumov-Gerasimenko
Context. On 12 March 2015 the OSIRIS WAC camera onboard the ESA Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko observed a small outburst originating from the Imhotep region at the foot of the big lobe of the comet. These measurements are unique since it was the first time that the initial phase of a transient outburst event could be directly observed. Aims. We investigate the evolution of the dust jet in order to derive clues about the outburst source mechanism and the ejected dust particles, in particular the dust mass, dust-to-gas ratio and the particle size distribution. Methods. Analysis of the images and of the observation geometry using comet shape models in combination with gasdynamic modeling of the transient dust jet were the main tools used in this study. Synthetic images were computed for comparison with the observations. Results. Analysis of the geometry revealed that the source region was not illuminated until 1.5 h after the event implying true nightside activity was observed. The outburst lasted for less than one hour and the average dust production rate during the initial four minutes was of the order of 1 kg/s. During this time the outburst dust production rate was approximately constant, no sign for an initial explosion could be detected. For dust grains between 0.01-1 mm a power law size distribution characterized by an index of about 2.6 provides the best fit to the observed radiance profiles. The dust-to-gas ratio of the outburst jet is in the range 0.6-1.8. © 2016 ESO.
The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB; Grant No. 74/10:2), and the ESA Technical Directorate is gratefully acknowledged. H. Rickman was also supported by Grant No. 2011/01/B/ST9/05442 of the Polish National Science Center.
Peer Reviewed
2017-03-07T09:22:33Z
2017-03-07T09:22:33Z
2016
2017-03-07T09:22:33Z
artículo
http://purl.org/coar/resource_type/c_6501
doi: 10.1051/0004-6361/201527744
issn: 1432-0746
Astronomy and Astrophysics 596: A89 (2016)
http://hdl.handle.net/10261/146268
10.1051/0004-6361/201527744
Publisher's version
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open
EDP Sciences