LOCATION AND MAGNETOSPHERIC MAPPING OF SATURN'S MID-LATITUDE INFRARED AURORAL OVAL

Journal Article · Sun Oct 10 04:00:00 EDT 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/722/1/L85· OSTI ID:21452753

Stallard, Tom; Melin, Henrik; Cowley, Stanley W. H. ^[1]; Miller, Steve ^[2]

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1. Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)
2. Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

Previous observations of Saturn's infrared aurorae have shown that a mid-latitude aurora exists significantly equatorward of the main auroral oval. Here, we present new results using data from four separate observing runs in 1998, 2003, 2008, and 2010. When combined, these provide a view of the mid-latitude aurora under a considerable range of viewing conditions, allowing the first calculation of the latitudinal position of this aurora to be made. This has shown that the mid-latitude aurora is located at the magnetic footprint of the region within the magnetosphere where the initial breakdown in corotation occurs, between 3 R {sub S} and the orbit of Enceladus ({approx}3.95 R {sub S}). We also confirm that this aurora is a continuous stable feature over a period of more than a decade and that an oval morphology is likely. When combined, these results indicate that the mid-latitude auroral oval is formed by currents driven by the breakdown process within the magnetosphere, in turn caused by mass loading from the torus of Enceladus, analogous with the volcanic moon Io's dominant role in the formation of Jupiter's main auroral oval.

• OSTI ID: 21452753
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 722; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AURORAE
AURORAL OVAL
JUPITER PLANET
MAGNETIC FIELDS
PLANETS
SATURN PLANET