Near-infrared observations of the Jovian ring and small satellites

The Jovian ring has been observed at 2.2 microns at a near-maximum opening angle of 3.2 deg and a phase angle of 2.2 deg. The 126,100 +/- 500 km ring radius at maximum brightness obtained is compatible with Voyager data at high phase angles. Circular orbital elements have also been obtained for the two small satellites (Metis and Adrastea) associated with the ring. A combination of these orbits with the Voyager imaging-based measurements of Synnott yields a substantial improvement in mean motion estimates.