References of "PRANGE, R"
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See detailMultispectral simultaneous diagnosis of Saturn's aurorae throughout a planetary rotation
Lamy, L.; Prangé, R.; Pryor, W. et al

in Journal of Geophysical Research. Space Physics (2013), 118

From 27 to 28 January 2009, the Cassini spacecraft remotely acquired combined observations of Saturn's southern aurorae at radio, ultraviolet, and infrared wavelengths, while monitoring ion injections in ... [more ▼]

From 27 to 28 January 2009, the Cassini spacecraft remotely acquired combined observations of Saturn's southern aurorae at radio, ultraviolet, and infrared wavelengths, while monitoring ion injections in the middle magnetosphere from energetic neutral atoms. Simultaneous measurements included the sampling of a full planetary rotation, a relevant timescale to investigate auroral emissions driven by processes internal to the magnetosphere. In addition, this interval coincidentally matched a powerful substorm-like event in the magnetotail, which induced an overall dawnside intensification of the magnetospheric and auroral activity. We comparatively analyze this unique set of measurements to reach a comprehensive view of kronian auroral processes over the investigated timescale. We identify three source regions for the atmospheric aurorae, including a main oval associated with the bulk of Saturn Kilometric Radiation (SKR), together with polar and equatorward emissions. These observations reveal the coexistence of corotational and subcorototational dynamics of emissions associated with the main auroral oval. Precisely, we show that the atmospheric main oval hosts short-lived subcorotating isolated features together with a bright, longitudinally extended, corotating region locked at the southern SKR phase. We assign the substorm-like event to a regular, internally driven, nightside ion injection possibly triggered by a plasmoid ejection. We also investigate the total auroral energy budget, from the power input to the atmosphere, characterized by precipitating electrons up to 20 keV, to its dissipation through the various radiating processes. Finally, through simulations, we confirm the search-light nature of the SKR rotational modulation and we show that SKR arcs relate to isolated auroral spots. We characterize which radio sources are visible from the spacecraft and we estimate the fraction of visible southern power to a few percent. The resulting findings are discussed in the frame of pending questions as the persistence of a corotating field-aligned current system within a subcorotating magnetospheric cold plasma, the occurrence of plasmoid activity, and the comparison of auroral fluxes radiated at different wavelengths. [less ▲]

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See detailMulti‐spectral simultaneous observations of Saturn's aurorae in Jan. 2009
Lamy, L.; Prange, R.; Gustin, Jacques ULg et al

Conference (2012)

Detailed reference viewed: 9 (3 ULg)
See detailSaturn's radio, UV and IR aurorae observed simultaneously by Cassini
Lamy, L.; Prangé, R.; Gustin, Jacques ULg et al

in European Planetary Science Congress 2010 (2010, September 01)

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Detailed reference viewed: 4 (1 ULg)
See detailHST STIS Observations of Saturn's Auroral Variations Concurrent with the Cassini Solar Wind Campaign in Jan. 2004
Clarke, J. T.; Gérard, Jean-Claude ULg; Grodent, Denis ULg et al

Conference (2004, May 17)

Saturn's magnetosphere is often referred to as "intermediate between the cases of the Earth and Jupiter". Due to very limited measurements of Saturn's magnetosphere and auroral activity, however, it has ... [more ▼]

Saturn's magnetosphere is often referred to as "intermediate between the cases of the Earth and Jupiter". Due to very limited measurements of Saturn's magnetosphere and auroral activity, however, it has never been clear in detail what this statement means. A recent campaign of HST STIS UV imaging of Saturn's aurora has been carried out over 8-30 Jan. 2004 concurrent with measurements of the approaching solar wind by Cassini. This imaging set is much more comprehensive than any earlier observations of Saturn's aurora, obtained at a time when Saturn's southern auroral oval is completely visible due to the large apparent tilt of Saturn. The data provide the opportunity to determine the mean distribution of the auroral emissions, the degree of corotation of any bright regions, any variations with local time of the emissions, the latitudinal motions of the main oval with time and location, and other parameters. In addition, each of these can be compared with the approaching solar wind conditions and Saturn's kilometric radiation (SKR) intensity from Cassini measurements. Quick looks at the data from HST and Cassini demonstrate that the measurements have been made successfully, and the coverage includes dramatic variations in Saturn's auroral activity as well as at least two solar wind shocks passing Cassini. This presentation will concentrate on the measured properties of Saturn's aurora in the context of comparisons with the magnetospheres of the Earth and Jupiter. [less ▲]

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Peer Reviewed
See detailHubble Space Telescope far-ultraviolet imaging of Jupiter during the impacts of Comet Shoemaker-Levy 9
Clarke, J. T.; Prange, R.; Ballester, G. E. et al

in Highlights of Astronomy, Vol. 10 (1995)

Detailed reference viewed: 14 (4 ULg)
See detailUltraviolet observations of the Saturnian north aurora and polar haze distribution with the HST-FOC
Gérard, Jean-Claude ULg; Dols, V.; Grodent, Denis ULg et al

in NASA STI/Recon Technical Report N (1995), 96

Near simultaneous observations of the Saturnian H2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the Hubble Space Telescope ... [more ▼]

Near simultaneous observations of the Saturnian H2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the Hubble Space Telescope. The auroral observations cover a complete rotation of the planet and, when co-added, reveal the presence of an auroral emission near 80 deg N with a peak brightness of about 150 kR of total H2 emission. The maximum optical depth of the polar haze layer is found to be located approximately 5 deg equatorward of the auroral emission zone. The haze particles are presumably formed by hydrocarbon aerosols initiated by H2+ auroral production. In this case, the observed haze optical depth requires an efficiency of aerosol formation of about 6 percent, indicating that auroral production of hydrocarbon aerosols is a viable source of high-latitude haze. [less ▲]

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See detailSIMULTANEOUS OBSERVATIONS OF THE SATURNIAN AURORA AND POLAR HAZE WITH THE HST/FOC
Gérard, Jean-Claude ULg; DOLS, V.; Grodent, Denis ULg et al

in Geophysical Research Letters (1995), 22(20), 2685-2688

Near simultaneous observations of the Saturnian H-2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the post-COSTAR Hubble ... [more ▼]

Near simultaneous observations of the Saturnian H-2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the post-COSTAR Hubble Space Telescope. The auroral observations cover a complete rotation of the planet and, when co-added, they reveal the presence of an auroral emission near 80 degrees N with a brightness of about 150 kR of total H-2 emission. The maximum vertical optical depth at 210 nm is found to be located similar to 5 degrees equatorward of the auroral emission zone. The haze particles are presumably formed by hydrocarbon aerosols initiated by H-2(+) auroral production. In this case, the 3 x 10(10) W of H-2 emission observed with the FOG, combined with the deduced haze optical depth requires an efficiency of aerosol formation of about 7%. This result indicates that auroral production of hydrocarbon aerosols is a viable source of high-latitude haze. [less ▲]

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See detailA REMARKABLE AURORAL EVENT ON JUPITER OBSERVED IN THE ULTRAVIOLET WITH THE HUBBLE-SPACE-TELESCOPE
Gérard, Jean-Claude ULg; Grodent, Denis ULg; Prangé, R. et al

in Science (1994), 266(5191), 1675-1678

Two sets of ultraviolet images of the Jovian north aurora were obtained with the Faint Object Camera on board the Hubble Space Telescope. The first series shows an intense discrete are in near corotation ... [more ▼]

Two sets of ultraviolet images of the Jovian north aurora were obtained with the Faint Object Camera on board the Hubble Space Telescope. The first series shows an intense discrete are in near corotation with the planet. The maximum apparent molecular hydrogen emission rate corresponds to an electron precipitation of similar to 1 watt per square meter, which is about 30,000 times larger than the solar heating by extreme ultraviolet radiation. Such a particle heating rate of the auroral upper atmosphere of Jupiter should cause a large transient temperature increase and generate strong thermospheric winds. Twenty hours after initial observation, the discrete are had decreased in brightness by more than one order of magnitude. The time scale and magnitude of the change in the ultraviolet aurora leads us to suggest that the discrete Jovian auroral precipitation is related to large-scale variations in the current system, as is the case for Earth's discrete aurorae. [less ▲]

Detailed reference viewed: 24 (11 ULg)
See detailHST-FOC observations of a remarkable UV auroral event on Jupiter
Gérard, Jean-Claude ULg; Grodent, Denis ULg; Prangé, R. et al

in NASA STI/Recon Technical Report N (1994), 95

Two sets of UV (ultraviolet) images of the Jovian north aurora were obtained with the Faint Object Camera (FOC) on Hubble. The first series shows a very intense discrete arc in corotation with the planet ... [more ▼]

Two sets of UV (ultraviolet) images of the Jovian north aurora were obtained with the Faint Object Camera (FOC) on Hubble. The first series shows a very intense discrete arc in corotation with the planet. The maximum apparent H2 emission rate corresponds to an electron precipitation of approximately 1/sq Wm, a very large flux in comparison with the solar EUV (extreme ultraviolet) heating. The hugh particle heating rate of the auroral upper atmosphere of Jupiter is expected to cause a large transient temperature increase and generate strong thermospheric winds. Twenty hours later, the discrete arc had considerably decreased in brightness. The timescale and magnitude of the change in the UV aurora strongly suggests that the discrete Jovian auroral precipitation is related to large scale current system variations as are the Earth's discrete aurorae. [less ▲]

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Peer Reviewed
See detailUltraviolet imaging of the Jovian aurora with the Hubble Space Telescope
Dols, V.; Gérard, Jean-Claude ULg; Paresce, F. et al

in Geophysical Research Letters (1992), 19

We present here for the first time a Lyman-alpha image of the north polar region of Jupiter obtained with the Faint Object Camera on board the Hubble Space Telescope a few hours after the encounter of the ... [more ▼]

We present here for the first time a Lyman-alpha image of the north polar region of Jupiter obtained with the Faint Object Camera on board the Hubble Space Telescope a few hours after the encounter of the ULYSSES spacecraft with Jupiter. The presence of high latitude regions of enhanced emission is clearly observed. A comparison with the location of the 'UVS oval', the Io (L = 6) and high-latitude field-line footprints shows that the best agreement is obtained with the L not less than 15 footprint and the UVS oval which are close to each other for the particular longitudinal sector observed. These two L-shells correspond to two possible sources of precipitation: particles originating respectively from the region of the plasma torus of Io in a distorted magnetic field or particles from the distant magnetosphere by analogy with the terrestrial aurora. [less ▲]

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See detailFar ultraviolet imaging of Jupiter's northern polar regions with the FOC
Gérard, Jean-Claude ULg; Dols, V.; Paresce, F. et al

in Science with the Hubble Space Telescope (1992)

Detailed reference viewed: 14 (3 ULg)
Peer Reviewed
See detailStudy of the neutral and ionized Io tori
Prangé, R.; Vidal-Madjar, A.; Gérard, Jean-Claude ULg

in The Messenger (1987)

Images of Io were obtained with the 2.2-m telescope at La Silla in the imaging code coupled with a CCD detector. The strong emission from Io's continuum was significantly decreased through the use of an ... [more ▼]

Images of Io were obtained with the 2.2-m telescope at La Silla in the imaging code coupled with a CCD detector. The strong emission from Io's continuum was significantly decreased through the use of an occulting mask in the telescope focal plane. It was found that a spectral resolution of 5 A or better was desirable. [less ▲]

Detailed reference viewed: 10 (2 ULg)