Solar occultation observations of Saturn's rings with Cassini UVIS

Abstract

The Ultraviolet Imaging Spectrograph (UVIS) instrument onboard the Cassini spacecraft observed 41 solar occultations by Saturn's rings through its extreme ultraviolet (56–118 nm) spectrographic channel. These solar occultations complement the set of stellar occultations measured by the broadband UVIS High Speed Photometer in the far ultraviolet (110–190 nm). We provide a uniform calibration of all of the UVIS solar occultation data across the full ring system. We have compiled complete catalogs of these occultations as high-level data products delivered to the Planetary Data System (PDS) Ring Moon Systems Node. This manuscript serves as a guide to this dataset and the corresponding high-level data products outlining their value for analysis of Saturn's rings. These products include light curves and optical depth profiles as functions of ring radius. In addition to providing key parameters of interest obtained through each of these occultations, we show that the optical depths of various ring regions derived from solar occultations are consistent with those from stellar occultations. We also demonstrate that fits to self-gravity wake parameters are similar for solar and stellar occultations. Lastly, we identify a variety of potential spectral trends at various ring locations that future investigations may further explore to address key questions pertaining to the properties of Saturn's rings.