Abstract
We report on a unique dusk-brightening event within Saturn's aurorae. Measurements of the H+3 infrared aurora using the CSHELL instrument on NASA's Infrared Telescope Facility (IRTF), made in 2005 December, show an auroral intensity structure unlike anything previously detected. The aurora has a significantly brighter dusk sector over three Earth nights, a period in excess of 5 Saturnian days, suggesting a consistent source for this emission, stable in position within the magnetosphere. However, unlike previously detected dawn-brightening events, the overall auroral brightness remains low and the ion wind structure appears unaffected. Using the location of magnetopause crossings as a proxy for the solar wind pressure, the solar wind appears to be exceptionally rarefied. This leads us to conclude that the dusk-brightening event is strongly linked with the unusual solar wind conditions at the time of the observations.
Original language | English |
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Pages (from-to) | L203-L206 |
Number of pages | 4 |
Journal | Astrophysical Journal Letters |
Volume | 673 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Feb 2008 |
Externally published | Yes |
Keywords
- atmospheric effects
- infrared : solar system
- planets and satellites : individual (Saturn)