Voyager Observations of Dust Scattered Starlig

Abstract

There are many different processes contributing to the diffuse ultraviolet radiation field: including heliospheric, Galactic, and extragalactic sources. Unfortunately, there are very few reliable observations of the ultraviolet background (see Murthy and Henry 1995), both due to the faintness of the signal and the need for space-based instrumentation. In this context, there has been a surprising neglect of the Voyager ultraviolet spectrometer (UVS) archives. Comprising more than 17 years of data from the long stretches when the two spacecraft were between their highly successful planetary encounters, these archives contain observations of a wide variety of astrophysical targets in the spectral region between 550 and 1700 Å. In the best cases, limits of about 100 photons cm-2 s-1 sr-1 Å-1 (Murthy, J. et al. 1991) can be set on the diffuse radiation field - sufficient to significantly constrain the various components of the UV background.