Saturn Auroral Images and Movies from Cassini UVIS

Cassini’s Ultraviolet Imaging Spectrograph (UVIS) has completed five
<br />years of study of Saturn’s atmosphere and auroras. Two long slit spectral channels are
<br />used to obtain EUV data from 56.3-118.2 nm and FUV data from 111.5-191.3 nm. 64
<br />spatial pixels along each slit are combined with slit motion to construct spectral images of
<br />Saturn. Auroral emissions are seen from electron-excited molecular and atomic hydrogen.
<br />In 2008-2009 UVIS obtained data with the spacecraft well out of Saturn’s ring plane,
<br />permitting UVIS to obtain a number of short movies of the rotating auroral structures.
<br />In some movies a cusp-like feature is present near noon inside the oval. One movie from
<br />2008 day 201 shows parallel linear features on the day side almost at right angles to
<br />the main auroral oval that appear, then lengthen, separate in the middle, and then fade
<br />away. The same movie also shows one bright "polar flare" inside the oval. A few of
<br />the most recent images were obtained at sufficiently close range that 2 spacecraft slews
<br />were needed to completely cover the oval. These images provide almost 100 pixels of
<br />information across the oval and clearly show multiple arcs of emission on the main oval
<br />and scattered emissions inside the oval. We will discuss these features, their locations, and
<br />possible interpretations. We also report on a search for an Enceladus auroral footprint
<br />on Saturn.