Comparison of IUE and HST diagnostics of the Jovian Aurorae

R. Prangé, S. Maurice, Walter M Harris, D. Rego, T. Livengood

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Analysis of international ultraviolet explorer (IUE) and Voyager ultraviolet spectrometer (UVS) spectra of the Jovian auroral emission indicates that the Jovian auroral brightness is modulated in longitude (brighter near 180° in the north and 20° in the south) and that there is a color ratio asymmetry associated with this brightening. The purpose of this study is to investigate the origin of this apparent asymmetry. To that end, we use a series of six typical images of the north auroral region taken in the H 2 Lyman bands with the faint object camera (FOC) aboard the Hubble space telescope (HST) and which cover a full Jovian rotation. Although the images do not display any strong brightening near 180°, once we have simulated the signal IUE would see through its aperture, we find the characteristic longitudinal modulation. We attribute most of this modulation to a combination of viewing geometry effects near the east and west ansae of the auroral oval (already taken into account in previous studies) and of the spatial degradation of the source by the IUE instrument function (never considered so far), and we suggest qualitatively that these effects may also affect the color ratio asymmetry. Nevertheless, part of the asymmetry seems to be due to an intrinsic modulation associated with a bright feature crossing the polar cap along the 160° meridian (transpolar emission) and present in most of the images. We then use a series of FOC images taken during an atypically strong auroral event, and we show that the same effects can again account for the anomalous brightness variations observed simultaneously with IUE.

Original languageEnglish (US)
Article number96JE03304
Pages (from-to)9289-9301
Number of pages13
JournalJournal of Geophysical Research: Space Physics
Volume102
Issue numberE4
StatePublished - 1997
Externally publishedYes

Fingerprint

Space telescopes
IUE
aurora
Hubble Space Telescope
asymmetry
faint object camera
Modulation
Ultraviolet instruments
Luminance
Cameras
modulation
Ultraviolet spectrometers
Color
brightness
ultraviolet spectrometers
color
polar caps
longitude
Degradation
spectrometer

Keywords

  • Ablation depth
  • Flat-top laser beam profile
  • Gaussian laser beam profile
  • High efficiency
  • Instrumentation
  • Ion source
  • IR MALDI-MS
  • Isotope ratios
  • Isotope separation
  • Mass spectrometry
  • Quadrupole
  • Thermal ionization
  • UV MALDI-MS

ASJC Scopus subject areas

  • Oceanography
  • Astronomy and Astrophysics
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Geophysics
  • Geochemistry and Petrology

Cite this

Prangé, R., Maurice, S., Harris, W. M., Rego, D., & Livengood, T. (1997). Comparison of IUE and HST diagnostics of the Jovian Aurorae. Journal of Geophysical Research: Space Physics, 102(E4), 9289-9301. [96JE03304].

Comparison of IUE and HST diagnostics of the Jovian Aurorae. / Prangé, R.; Maurice, S.; Harris, Walter M; Rego, D.; Livengood, T.

In: Journal of Geophysical Research: Space Physics, Vol. 102, No. E4, 96JE03304, 1997, p. 9289-9301.

Research output: Contribution to journalArticle

Prangé, R, Maurice, S, Harris, WM, Rego, D & Livengood, T 1997, 'Comparison of IUE and HST diagnostics of the Jovian Aurorae', Journal of Geophysical Research: Space Physics, vol. 102, no. E4, 96JE03304, pp. 9289-9301.
Prangé R, Maurice S, Harris WM, Rego D, Livengood T. Comparison of IUE and HST diagnostics of the Jovian Aurorae. Journal of Geophysical Research: Space Physics. 1997;102(E4):9289-9301. 96JE03304.
Prangé, R. ; Maurice, S. ; Harris, Walter M ; Rego, D. ; Livengood, T. / Comparison of IUE and HST diagnostics of the Jovian Aurorae. In: Journal of Geophysical Research: Space Physics. 1997 ; Vol. 102, No. E4. pp. 9289-9301.
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