Authors: Scharringhausen Britt R., Nicholson Philip D., Brandl Bernhard, Hayward Thomas L., Dekany Richard G., Troy Mitchell, and Bloemhof Eric E.
Year: 2003
Title: Adaptive optics observations of small moons of saturn*
Journal: Icarus
Volume: 162
Number: 2
Pages: 385-390
Keywords: Saturn, small, planetology, observation, position, CCD, data
Abstract: We report near-infrared observations of Prometheus and Janus taken on 9 and 13 November 2000 (UT) with the Palomar Adaptive Optics System on the 5-m Hale telescope at Palomar Observatory. Dione, Rhea, and Tethys were used as guide ``stars'' for the adaptive optics system, and, though they were outside the isoplanatic patch of the region of interest, they allowed significant correction of the atmospheric turbulence. Prometheus, which is usually impossible to observe from the ground due to scattered light from the A ring, was imaged at superior conjunction with Saturn. At the time of the observations, the rings of Saturn were blocked by the southern limb of the planet while the moon passed just 0.35'' below the planet's south pole. A K filter, in a methane absorption band, was used to suppress light from the disk of the planet, and template subtraction removed much of the scattered light from the A ring. Prometheus was found to be 21.9 +/- 0.1° of mean longitude behind the position predicted by Voyager-era ephemerides, consistent with the orbital lag discovered during the 1995 ring-plane crossing.
%F: AA(Department of Astronomy, Cornell University, 14583, Ithaca, NY, USA), AB(Department of Astronomy, Cornell University, 14583, Ithaca, NY, USA), AC(Department of Astronomy, Cornell University, 14583, Ithaca, NY, USA), AD(Gemini Observatory, Casilla 603,, La Serena, Chile), AE(California Institute of Technology, 91109, Pasadena, CA, USA), AF(Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109, Pasadena, CA, USA), AG(Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, 91109, Pasadena, CA, USA)
Bibliogaphic Code: 2003Icar..162..385S
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