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

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.; ... (2017). Dust mass distribution around comet 67P/Churyumov–Gerasimenko determined via parallax measurements using Rosetta's OSIRIS cameras. Monthly notices of the Royal Astronomical Society, 469(Suppl_2), S276-S284. Oxford University Press 10.1093/mnras/stx1419

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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 10⁻⁶–10² kg and a mean velocity of about 2.4 m s⁻¹ 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 Af ρ of the comet around perihelion. The summed-up dust mass-loss rate for the mass bins 10⁻⁴–10² kg is almost 8300 kg s⁻¹.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences

UniBE Contributor:

Thomas, Nicolas

Subjects:

500 Science > 520 Astronomy
600 Technology > 620 Engineering

ISSN:

0035-8711

Publisher:

Oxford University Press

Language:

English

Submitter:

Dora Ursula Zimmerer

Date Deposited:

06 Apr 2018 15:37

Last Modified:

06 Apr 2018 15:37

Publisher DOI:

10.1093/mnras/stx1419

BORIS DOI:

10.7892/boris.107569

URI:

https://boris.unibe.ch/id/eprint/107569

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