An observation of a mutual event between two satellites of Uranus

Authors: M. G. Hidas (1 and 2), A. A. Christou (3), T. M. Brown (1 and 2) ((1) Las Cumbres Observatory Global Telescope, (2) University of California, Santa Barbara, (3) Armagh Observatory)

(Submitted on 13 Nov 2007)

Abstract: We present observations of the occultation of Umbriel by Oberon on 4 May, 2007. We believe this is the first observed mutual event between satellites of Uranus. Fitting a simple geometric model to the lightcurve, we measure the mid-event time with a precision of 4 seconds. We assume previously measured values for the albedos of the two satellites (Karkoschka 2001), and measure the impact parameter to be 500 +/- 80 km. These measurements are more precise than estimates based on current ephemerides for these satellites. Therefore observations of additional mutual events during the 2007-2008 Uranian equinox will provide improved estimates of their orbital and physical parameters.

Comments: 4 pages, 3 figures, accepted for publication in MNRAS Letters

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0711.2095v1 [astro-ph]

Submission history

From: M\'arton Hidas [view email]

[v1] Tue, 13 Nov 2007 23:43:04 GMT (227kb)

http://arxiv.org/abs/0711.2095