Visible and Near-Infrared Spectrophotometry of Saturn's Rings.

Abstract

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Visible and Near-Infrared Spectrophotometry of Saturn's Rings. Younkin, Robert L. ; Münch, Guido Abstract Measurements of the narrow-band spectral energy distribution of the rings of Saturn have been made at the Mount Wilson Observatory using the 60-in. reflector and the Fastie- Ebert spectrometer. Spectral scans from 0.51 to 1.1 IL were made of a segment of the rings at the western end of the semimajor aXls. The energy distribution was determined at 54 points in this wavelength region. The color sensitivity of the system was determined from scans of a Lyr and the a Lyr energy distribution of Oke. The relative reflectance of the rings was calculated by use of the solar intensity values of Labs and Neckel, converted to solar flux by the ratios of Minnaert. The reflectance of the rings is very nearly constant from 0.78 to 1.05 IL Shortward of this region it falls slowly to 0.60 IL' then more rapidly to a value at 0.51 IL some 0m.45 below the maximum. There is a slight decrease in reflectance (0~~03~0m.0S) from 1.05 to 1.08 IL This is marginally outside of the experimental error. Owen has recently reported a drop in the reflectance of the rings from 1.04 to 1.09 IL' whid~ he identified as due to water ice. This drop was determined on the basis of a drop in the ratio of the intensity of the rings to the intensity of Saturn in this region. Separate measurements at Mount Wilson of the reflectance of Saturn show a continuous strong absorption from 0.97 to 1.04 IL This unfortuitous coincidence yields a large drop in the ratio beyond 1.04 IL which will completely mask any possible ice absorption which by the results above will be only a few percent at most. Publication: The Astronomical Journal Pub Date: February 1966 DOI: 10.1086/110094 Bibcode: 1966AJ.....71R.188Y full text sources ADS |