An observation of a mutual event between two satellites of Uranus
Abstract
We present observations of the occultation of Umbriel by Oberon on 2007 May 4. We believe this is the first observed mutual event between satellites of Uranus. Fitting a simple geometric model to the light curve, we measure the mid-event time with a precision of 4 s. We assume previously measured values for the albedos of the two satellites, 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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2008
- DOI:
- 10.1111/j.1745-3933.2007.00418.x
- arXiv:
- arXiv:0711.2095
- Bibcode:
- 2008MNRAS.384L..38H
- Keywords:
-
- occultations;
- planets and satellites: individual: Umbriel;
- planets and satellites: individual: Oberon;
- Astrophysics
- E-Print:
- 4 pages, 3 figures, accepted for publication in MNRAS Letters