EDP Sciences
Free access
Volume 365, Number 2, January II 2001
Page(s) 214 - 221
Section The solar system
DOI http://dx.doi.org/10.1051/0004-6361:20000183

A&A 365, 214-221 (2001)
DOI: 10.1051/0004-6361:20000183

Detection of arcs in Saturn's F ring during the 1995 Sun ring-plane crossing

S. Charnoz1 , A. Brahic1 , C. Ferrari1 , I. Grenier1 , F. Roddier2 and P. Thébault3 .

1  Équipe Gamma-Gravitation, Service d'Astrophysique, CEA/Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France
2  Institute for Astronomy, University of Hawai, 2680 Woodlawn Drive, Honolulu, Hawai 96822, Hawai
3  DESPA, Observatoire de Paris, 92195 Meudon Cedex Principal, France

(Received 24 July 2000 / Accepted 19 October 2000 )

Observations of the November 1995 Sun crossing of the Saturn's ring-plane made with the 3.6 m CFH telescope, using the UHAO adaptive optics system, are presented here. We report the detection of four arcs located in the vicinity of the F ring. They can be seen one day later in HST images. The combination of both data sets gives accurate determinations of their orbits. Semi-major axes range from 140 020 km to 140 080 km, with a mean of $140 060 \pm 60$ km. This is about 150 km smaller than previous estimates of the F ring radius from Voyager 1 and 2 data, but close to the orbit of another arc observed at the same epoch in HST images.

Key words: planets: individual: Saturn

Offprint request: S. Charnoz, charnoz@discovery.saclay.cea.fr

© ESO 2001