Bockelee-Morvan, D. und Rinaldi, G. und Erard, S. und Leyrat, C. und Capaccioni, F. und Drossart, P. und Filacchione, G. und Migliorini, A. und Quirico, E. und Mottola, Stefano und Tozzi, G. und Arnold, Gabriele und Biver, N und Combes, M. und Crovisier, J. und Longobardo, A und Blecka, M. und Capria, M. T. (2017) Comet 67P outbursts and quiescent coma at 1.3 au from the Sun: dust properties from Rosetta/VIRTIS-H observations. Monthly Notices of the Royal Astronomical Society, 469, S443-S458. Oxford University Press. doi: 10.1093/mnras/stx1950. ISSN 0035-8711.
PDF
3MB |
Offizielle URL: https://academic.oup.com/mnras/article/469/Suppl_2/S443/4060719
Kurzfassung
We present 2-5 μm spectroscopic observations of the dust coma of 67P/Churyumov-Gerasimenko obtained with the VIRTIS-H instrument onboard Rosetta during two outbursts that occurred on 2015, 13 September 13.6 h ut and 14 September 18.8 h ut at 1.3 au from the Sun. Scattering and thermal properties measured before the outburst are in the mean of values measured for moderately active comets. The colour temperature excess (or superheat factor) can be attributed to submicrometre-sized particles composed of absorbing material or to porous fractal-like aggregates such as those collected by the Rosetta in situ dust instruments. The power-law index of the dust size distribution is in the range 2-3. The sudden increase of infrared emission associated with the outbursts is correlated with a large increase of the colour temperature (from 300 to 630 K) and a change of the dust colour at 2-2.5 μm from red to blue colours, revealing the presence of very small grains (<=100 nm) in the outburst material. In addition, the measured large bolometric albedos (∼0.7) indicate bright grains in the ejecta, which could either be silicatic grains, implying the thermal degradation of the carbonaceous material, or icy grains. The 3 μm absorption band from water ice is not detected in the spectra acquired during the outbursts, whereas signatures of organic compounds near 3.4 μm are observed in emission. The H2O 2.7 μm and CO2 4.3 μm vibrational bands do not show any enhancement during the outbursts.
elib-URL des Eintrags: | https://elib.dlr.de/126090/ | ||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dokumentart: | Zeitschriftenbeitrag | ||||||||||||||||||||||||||||||||||||||
Titel: | Comet 67P outbursts and quiescent coma at 1.3 au from the Sun: dust properties from Rosetta/VIRTIS-H observations | ||||||||||||||||||||||||||||||||||||||
Autoren: |
| ||||||||||||||||||||||||||||||||||||||
Datum: | 2 August 2017 | ||||||||||||||||||||||||||||||||||||||
Erschienen in: | Monthly Notices of the Royal Astronomical Society | ||||||||||||||||||||||||||||||||||||||
Open Access: | Ja | ||||||||||||||||||||||||||||||||||||||
In SCOPUS: | Ja | ||||||||||||||||||||||||||||||||||||||
In ISI Web of Science: | Ja | ||||||||||||||||||||||||||||||||||||||
Band: | 469 | ||||||||||||||||||||||||||||||||||||||
DOI: | 10.1093/mnras/stx1950 | ||||||||||||||||||||||||||||||||||||||
Seitenbereich: | S443-S458 | ||||||||||||||||||||||||||||||||||||||
Verlag: | Oxford University Press | ||||||||||||||||||||||||||||||||||||||
Name der Reihe: | Monthly Notices of the Royal Astronomical Society | ||||||||||||||||||||||||||||||||||||||
ISSN: | 0035-8711 | ||||||||||||||||||||||||||||||||||||||
Stichwörter: | comets: general, comets: individual: 67P/Churyumov-Gerasimenko, infrared: planetary systems | ||||||||||||||||||||||||||||||||||||||
DLR - Schwerpunkt: | Raumfahrt | ||||||||||||||||||||||||||||||||||||||
DLR - Forschungsgebiet: | R EW - Erforschung des Weltraums | ||||||||||||||||||||||||||||||||||||||
Standort: | Berlin-Adlershof | ||||||||||||||||||||||||||||||||||||||
Institute & Einrichtungen: | Institut für Planetenforschung > Leitungsbereich PF Institut für Planetenforschung > Asteroiden und Kometen |
Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags