Feller, C. and Fornasier, S. and Hasselmann, P.H. and Barucci, A. and Preusker, F. and Scholten, F. and Jorda, L. and Pommerol, A. and Jost, B. and Poch, O. and El-Maarry, Mohamed Ramy and Thomas, N. and Belskaya, I. and Pajola, M. and Sierks, H. and Barbieri, C. and Lamy, P.L. and Koschny, D. and Rickman, H. and Rodrigo, R. and Agarwal, J. and A’Hearn, M. and Bertaux, J.-L. and Bertini, I. and Boudreault, S. and Cremonese, G. and Da Deppo, V. and Davidsson, B.J.R. and Debei, S. and De Cecco, M. and Deller, J. and Fulle, M. and Giquel, A. and Groussin, O. and Gutierrez, P.J. and Güttler, C. and Hofmann, M. and Hviid, S.F. and Keller, H. and Ip, W.-H. and Knollenberg, J. and Kovacs, G. and Kramm, J.-R. and Kührt, E. and Küppers, M. and Lara, M.L. and Lazzarin, M. and Leyrat, C. and Lopez Moreno, J.J. and Marzari, F. and Masoumzadeh, N. and Mottola, S. and Naletto, G. and Perna, D. and Oklay, N. and Shi, X. and Tubiana, C. and Vincent, J.-B. (2016) Decimetre-scaled spectrophotometric properties of the nucleus of comet 67P/Churyumov–Gerasimenko from OSIRIS observations. Monthly Notices of the Royal Astronomical Society 462 (Suppl), S287-S303. ISSN 0035-8711.
Abstract
We present the results of the photometric and spectrophotometric properties of the 67P/Churyumov–Gerasimenko nucleus derived with the Optical, Spectroscopic and Infrared Remote Imaging System instrument during the closest fly-by over the comet, which took place on 2015 February 14 at a distance of ∼6 km from the surface. Several images covering the 0°–33° phase angle range were acquired, and the spatial resolution achieved was 11 cm pixel−1. The flown-by region is located on the big lobe of the comet, near the borders of the Ash, Apis and Imhotep regions. Our analysis shows that this region features local heterogeneities at the decimetre scale. We observed difference of reflectance up to 40 per cent between bright spots and sombre regions, and spectral slope variations up to 50 per cent. The spectral reddening effect observed globally on the comet surface by Fornasier et al. (2015) is also observed locally on this region, but with a less steep behaviour. We note that numerous metre-sized boulders, which exhibit a smaller opposition effect, also appear spectrally redder than their surroundings. In this region, we found no evidence linking observed bright spots to exposed water-ice-rich material. We fitted our data set using the Hapke 2008 photometric model. The region overflown is globally as dark as the whole nucleus (geometric albedo of 6.8 per cent) and it has a high porosity value in the uppermost layers (86 per cent). These results of the photometric analysis at a decimetre scale indicate that the photometric properties of the flown-by region are similar to those previously found for the whole nucleus.
Metadata
| Item Type: | Article |
|---|---|
| Keyword(s) / Subject(s): | methods: data analysis, space vehicles, space vehicles: instruments, techniques: image processing, techniques: photometric, comets: individual: 67P/Churyumov, Gerasimenko |
| School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
| Depositing User: | Administrator |
| Date Deposited: | 09 Nov 2018 15:05 |
| Last Modified: | 02 Aug 2023 17:46 |
| URI: | https://eprints.bbk.ac.uk/id/eprint/25025 |
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