Search Publications
Observational Constraints on the Lifetime of Cometary H 2O
Cochran, Anita L.; Schleicher, David G.
We used a carefully selected set of observations of five comets along with a vectorial model and the Haser model to explore the lifetimes against photodissociation of H2O and OH in cometary comae. The photometric and long-slit CCD data described in this paper were obtained specifically for this project, while the IUE data are archival. …
Saturn's Upper Atmospheric Hazes Observed by the Hubble Space Telescope
Karkoschka, Erich; Tomasko, Martin G.
We observed Saturn with the Hubble Space Telescope at wavelengths 0.30-0.89 µm for the purpose of determining the distribution of hazes. In the stratosphere, haze optical depths in the ultraviolet are essentially zero for midnorthern latitudes, are small (∼0.2) at low latitudes and mid-southern latitudes, but large (almost unity) above 70° n…
Water Production Rates in Comet P/Halley from IUE Observations of HI Lyman-β
Feldman, Paul D.; Combi, Michael R.
During the 1985-1986 apparition of Comet P/Halley, the International Ultraviolet Explorer (IUE) satellite observed the comet using both the long-wavelength and short-wavelength spectrographs. The combination of a spherical radiative transfer model and the hybrid gas-dynamic/Monte Carlo model for hydrogen coma, which had been used to analyze H Lyma…
Image Deconvolution of Extended Objects: A Comparison of the Inverse Fourier and the Lucy Techniques
Cunningham, C. C.; Anthony, D.
We have investigated the relative effectiveness of two deconvolution techniques in restoring spherically aberrated Hubble Space Telescope (HST) images. These images were restricted to extended objects (such as planets) of high signal-to-noise. Our reason for pursuing these studies was that one of the deconvolution methods, the Lucy iterative techn…