Dust mass distribution around comet 67P/Churyumov-Gerasimenko determined via parallax measurements using Rosetta's OSIRIS cameras

DOI: 
10.1093/mnras/stx1419
Publication date: 
01/07/2017
Main author: 
Ott, T.
IAA authors: 
Gutiérrez, P. J.;Lara, L. M.;López-Moreno, J. J.
Authors: 
Ott, T.;Drolshagen, E.;Koschny, D.;Güttler, C.;Tubiana, C.;Frattin, E.;Agarwal, J.;Sierks, H.;Bertini, I.;Barbieri, C.;Lamy, P. I.;Rodrigo, R.;Rickman, H.;A'Hearn, M. F.;Barucci, M. A.;Bertaux, J. -L.;Boudreault, S.;Cremonese, G.;Da Deppo, V.;Davidsson, B.;Debei, S.;De Cecco, M.;Deller, J.;Feller, C.;Fornasier, S.;Fulle, M.;Geiger, B.;Gicquel, A.;Groussin, O.;Gutiérrez, P. J.;Hofmann, M.;Hviid, S. F.;Ip, W. -H.;Jorda, L.;Keller, H. U.;Knollenberg, J.;Kovacs, G.;Kramm, J. R.;Kührt, E.;Küppers, M.;Lara, L. M.;Lazzarin, M.;Lin, Z. -Y.;López-Moreno, J. J.;Marzari, F.;Mottola, S.;Naletto, G.;Oklay, N.;Pajola, M.;Shi, X.;Thomas, N.;Vincent, J. -B.;Poppe, B.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Volume: 
469
Pages: 
S276-S284
Abstract: 

The OSIRIS (optical, spectroscopic and infrared remote imaging system) instrument on board the ESA Rosetta spacecraft collected data of 67P/Churyumov-Gerasimenko for over 2 yr. OSIRIS consists of two cameras, a Narrow Angle Camera and a Wide Angle Camera. For specific imaging sequences related to the observation of dust aggregates in 67P's coma, the two cameras were operating simultaneously. The two cameras are mounted 0.7 m apart from each other, as a result this baseline yields a parallax shift of the apparent particle trails on the analysed images directly proportional to their distance. Thanks to such shifts, the distance between observed dust aggregates and the spacecraft was determined. This method works for particles closer than 6000 m to the spacecraft and requires very few assumptions. We found over 250 particles in a suitable distance range with sizes of some centimetres, masses in the range of 10<SUP>-6</SUP>-10<SUP>2</SUP> kg and a mean velocity of about 2.4 m s<SUP>-1</SUP> relative to the nucleus. Furthermore, the spectral slope was analysed showing a decrease in the median spectral slope of the particles with time. The further a particle is from the spacecraft the fainter is its signal. For this reason, this was counterbalanced by a debiasing. Moreover, the dust mass-loss rate of the nucleus could be computed as well as the Afρ of the comet around perihelion. The summed-up dust mass-loss rate for the mass bins 10<SUP>-4</SUP>-10<SUP>2</SUP> kg is almost 8300 kg s<SUP>-1</SUP>.

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037040629&doi=10.1093%2fmnras%2fstx1419&partnerID=40&md5=19fc8bcbcbdec133ba54643c7e45be48
ADS Bibcode: 
2017MNRAS.469S.276O
Keywords: 
techniques: image processing;parallaxes;comets: general;comets: individual: 67P/Churyumov-Gerasimenko