EDP Sciences
Free Access
Volume 441, Number 1, October I 2005
Page(s) 379 - 389
Section Planets and planetary systems
DOI https://doi.org/10.1051/0004-6361:20053100

A&A 441, 379-389 (2005)
DOI: 10.1051/0004-6361:20053100

Imaging Saturn's rings with CAMIRAS: thermal inertia of B and C rings

C. Ferrari1, P. Galdemard1, P. O. Lagage1, E. Pantin1 and C. Quoirin2

1  Laboratoire AIM, Unité Mixte de Recherche No. 7158 CEA-CNRS-Université Paris 7, France
    e-mail: cferrari@cea.fr,galdemard@cea.fr,lagage@cea.fr,epantin@cea.fr
2  Université Paris 6 - Pierre et Marie Curie, France

(Received 21 March 2005 / Accepted 11 May 2005)

Thermal inertias $\Gamma$ of Saturn's B and C ring particles have been derived from infrared observations using the CAMIRAS camera mounted on the Canada-France-Hawaii Telescope. They are respectively $\Gamma_{\rm B}=5^{+18}_{-2}$  ${\rm J \,m^{-2}\, K^{-1} \,s^{-1/2}}$ and $\Gamma_{\rm C}=6^{+12}_{-4}$ ${\rm J \,m^{-2}\, K^{-1} \,s^{-1/2}}$. Such low values might be characteristic of a frosty and porous regolith fractured by cracks or of very porous particle aggregates. Particles have to be slowly spinning to explain the observed ring temperatures. A large azimuthal asymmetry with an amplitude about 1 K is detected on the West ansa of the B ring. It cannot be explained by a model that considers the ring as a slab of low thermal inertia rapidly warming up to the sunlight after its eclipse into the planetary shadow.

Key words: planetary rings -- infrared: solar system -- conduction -- radiation mechanism: thermal

SIMBAD Objects

© ESO 2005

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.