Dusk-brightening event in Saturn's H3+ aurora

Tom Stallard; Steve Miller; Makenzie Lystrup; Nicholas Achilleos; Chris Arridge; Michele Dougherty

doi:10.1086/527545

Dusk-brightening event in Saturn's H3+ aurora

Tom Stallard^*, Steve Miller, Makenzie Lystrup, Nicholas Achilleos, Chris Arridge, Michele Dougherty

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

8 Citations (Scopus)

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
Pages (from-to)	L203-L206
Number of pages	4
Journal	Astrophysical Journal Letters
Volume	673
Issue number	2
DOIs	https://doi.org/10.1086/527545
Publication status	Published - 1 Feb 2008
Externally published	Yes

Keywords

atmospheric effects
infrared : solar system
planets and satellites : individual (Saturn)

Access to Document

10.1086/527545

Cite this

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title = "Dusk-brightening event in Saturn's H3+ aurora",

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.",

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author = "Tom Stallard and Steve Miller and Makenzie Lystrup and Nicholas Achilleos and Chris Arridge and Michele Dougherty",

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TY - JOUR

T1 - Dusk-brightening event in Saturn's H3+ aurora

AU - Stallard, Tom

AU - Miller, Steve

AU - Lystrup, Makenzie

AU - Achilleos, Nicholas

AU - Arridge, Chris

AU - Dougherty, Michele

PY - 2008/2/1

Y1 - 2008/2/1

N2 - 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.

AB - 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.

KW - atmospheric effects

KW - infrared : solar system

KW - planets and satellites : individual (Saturn)

U2 - 10.1086/527545

DO - 10.1086/527545

M3 - Article

SN - 2041-8205

VL - 673

SP - L203-L206

JO - Astrophysical Journal Letters

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