Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/30767
Title: | Comet 67P outbursts and quiescent coma at 1.3 au from the Sun: dust properties from Rosetta/VIRTIS-H observations | Authors: | Bockelée-Morvan, D. RINALDI, GIOVANNA Erard, S. Leyrat, C. CAPACCIONI, FABRIZIO Drossart, P. FILACCHIONE, GIANRICO MIGLIORINI, Alessandra Quirico, E. Mottola, S. Tozzi, G. Arnold, G. Biver, N. Combes, M. Crovisier, J. LONGOBARDO, ANDREA Blecka, M. CAPRIA, MARIA TERESA |
Issue Date: | 2017 | Journal: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | Number: | 469 | Issue: | Suppl_2 | First Page: | S443 | Abstract: | 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 H<SUB>2</SUB>O 2.7 μm and CO<SUB>2</SUB> 4.3 μm vibrational bands do not show any enhancement during the outbursts. | URI: | http://hdl.handle.net/20.500.12386/30767 | URL: | arXiv:1708.00210 https://academic.oup.com/mnras/article/469/Suppl_2/S443/4060719 |
ISSN: | 0035-8711 | DOI: | 10.1093/mnras/stx1950 | Bibcode ADS: | 2017MNRAS.469S.443B | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Bockelee_et_al_2017_1708.00210.pdf | preprint | 5.37 MB | Adobe PDF | View/Open |
stx1950.pdf | Pdf editoriale | 3.38 MB | Adobe PDF | View/Open |
Page view(s)
53
checked on Sep 11, 2024
Download(s)
34
checked on Sep 11, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.