Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
See detailAuroral Signature of the Interaction of Comet Shoemaker-Levy 9 with the Jovian Magnetosphere
Prangé; Emerich, C.; Rego, D. et al

in Bulletin of the American Astronomical Society (1994, June 01)

Not Available

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailAuroral signatures of flow bursts released during magnetotail reconnection at Jupiter
Radioti, Aikaterini ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

in Journal of Geophysical Research. Space Physics (2010), 115

Recent studies based on Hubble Space Telescope (HST) data reported the presence of transient polar dawn spots in the Jovian auroral region and interpreted them as signatures of internally driven magnetic ... [more ▼]

Recent studies based on Hubble Space Telescope (HST) data reported the presence of transient polar dawn spots in the Jovian auroral region and interpreted them as signatures of internally driven magnetic reconnection in the Jovian magnetotail. Even though an association of the polar dawn spots with the reconnection process has been suggested, it has not been yet investigated which part of the process and what mechanism powers these auroral emissions. In the present study, we examine the scenario that the auroral spots are triggered by the inward moving flow bursts released during magnetic reconnection at Jupiter. We base our analysis on a model adapted from the terrestrial case, according to which moving plasma flow burst is coupled with the ionosphere by field-aligned currents, giving rise to auroral emissions. We estimate the upward field-aligned current at the flank of the flow bursts, using in-situ magnetic field measurements and we derive the auroral emitted power. We statistically study the observed emitted power of the polar dawn spots, based on HST data from 1998 to 2007, and we compare it with the emitted power derived according to the proposed scenario. Apart from the emitted power, other properties of the polar dawn spots such as their location, periodicity, duty cycle and multiplicity suggest that they are associated with the inward moving flow bursts released during magnetic reconnection in Jupiter's tail. [less ▲]

Detailed reference viewed: 31 (3 ULg)
See detailAuroral signatures of injections in the magnetosphere of Saturn
Radioti, Aikaterini ULg; Roussos, E.; Grodent, Denis ULg et al

Poster (2011, July 11)

Detailed reference viewed: 24 (14 ULg)
Full Text
Peer Reviewed
See detailAuroral signatures of multiple magnetopause reconnection at Saturn
Radioti, Aikaterini ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

in Geophysical Research Letters (2013)

Detailed reference viewed: 16 (5 ULg)
See detailAuroral signatures of reconnection at Saturn and comparison with Earth
Radioti, Aikaterini ULg

Conference (2014, July)

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailAn auroral source of hot oxygen in the geocorona
Shematovich, V. I.; Bisikalo, D. V.; Gérard, Jean-Claude ULg

in Geophysical Research Letters (2005), 32

The high-energy proton-hydrogen (H[SUP]+[/SUP]/H) beam associated with proton auroral precipitation transfers momentum in elastic and inelastic collisions with ambient thermal atomic oxygen in the high ... [more ▼]

The high-energy proton-hydrogen (H[SUP]+[/SUP]/H) beam associated with proton auroral precipitation transfers momentum in elastic and inelastic collisions with ambient thermal atomic oxygen in the high latitude thermosphere. This process provides a localized novel source of hot oxygen atoms in addition to exothermic photochemistry, charge exchange and momentum transfer from O[SUP]+[/SUP] ion precipitation and charge exchange with accelerated ionospheric O[SUP]+[/SUP] ions. We suggest that this source contributes to the population of the hot oxygen geocorona and to the flux of escaping oxygen atoms. For an incident proton energy flux of 1 mW m[SUP]-2[/SUP] and a mean energy E[SUB]mean[/SUB] ~ 5 keV, we calculate a density of hot oxygen atoms with energy above 1 eV of 2.0 × 10[SUP]3[/SUP] cm[SUP]-3[/SUP] and a mean kinetic energy of about 3.5 eV at 700 km. The total upward flux of hot oxygen atoms with energies higher 1 eV is estimated as 3.5 × 10[SUP]8[/SUP] cm[SUP]-2[/SUP] s[SUP]-1[/SUP]. [less ▲]

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailAuroral streamers and magnetic flux closure
Hubert, Benoît ULg; Kauristie, K.; Amm, O. et al

in Geophysical Research Letters (2007), 34(15),

On 7 December 2000 at 2200 UT an auroral streamer was observed to develop above Scandinavia with the IMAGE-FUV global imagers. The ionospheric equivalent current deduced from the MIRACLE-IMAGE ... [more ▼]

On 7 December 2000 at 2200 UT an auroral streamer was observed to develop above Scandinavia with the IMAGE-FUV global imagers. The ionospheric equivalent current deduced from the MIRACLE-IMAGE Scandinavian ground-based network of magnetometers is typical of a substorm-time streamer. Observations of the proton aurora using the SI12 imager onboard the IMAGE satellite are combined with measurements of the ionospheric convection obtained by the SuperDARN radar network to compute the dayside merging and nightside flux closure rates. On the basis of this and other similar events, it is found that auroral streamers appear during the period of most intense flux closure in the magnetotail, most often shortly after substorm onset. The ionospheric convection velocity, as measured by SuperDARN, appears to be reduced in the vicinity of the streamer, suggesting de-coupling of magnetospheric and ionospheric plasma flows in the region of enhanced ionospheric conductance. [less ▲]

Detailed reference viewed: 15 (0 ULg)
See detailAuroral ultraviolet emissions
Gérard, Jean-Claude ULg

in Physics and chemistry of atmospheres (1975)

Detailed reference viewed: 3 (1 ULg)
Full Text
Peer Reviewed
See detailL'Aurore des fanzineux
Capart, Philippe; Dejasse, Erwin ULg; Paques, Frédéric ULg

in Art&Fact (2012), 31

Detailed reference viewed: 25 (9 ULg)
See detailLes aurores boréales sur les planètes géantes. La « crise énergétique des planètes géantes »
Grodent, Denis ULg

Conference given outside the academic context (2011)

Les planètes géantes comme Jupiter et Saturne ont en commun une masse importante, l’absence de surface, une atmosphère dominée par l’hydrogène moléculaire et l’hélium ainsi qu'une grande variété ... [more ▼]

Les planètes géantes comme Jupiter et Saturne ont en commun une masse importante, l’absence de surface, une atmosphère dominée par l’hydrogène moléculaire et l’hélium ainsi qu'une grande variété d’hydrocarbures. Leur rotation rapide est à l'origine d'un champ magnétique particulièrement intense qui permet de transférer de grandes quantités d'énergie de la planète vers les particules ionisées qui les entourent. Cet échange s'effectue via des courants électriques extrêmement intenses qui, en interagissant avec l'atmosphère, provoquent des émissions aurorales. Nous décrirons des processus de précipitation d’électrons énergétiques dans l'atmosphère de Jupiter et nous nous intéresserons aux spectaculaires aurores polaires qui leur sont associées. Ces dernières seront illustrées par des images et animations obtenues dans l’ultraviolet à l’aide du Télescope Spatial Hubble. Nous montrerons comment les précipitations aurorales contrôlent dans une large mesure la température de la haute atmosphère de ces planètes et permettent de résoudre la « crise énergétique » des planètes géantes. [less ▲]

Detailed reference viewed: 13 (1 ULg)
See detailLes aurores dans le système solaire
Grodent, Denis ULg

Conference given outside the academic context (2002)

Detailed reference viewed: 3 (1 ULg)
See detailLes aurores de Jupiter et Saturne : la crise énergétique des planètes géantes
Grodent, Denis ULg

Conference given outside the academic context (2011)

Detailed reference viewed: 4 (0 ULg)
See detailAurores sur les planètes géantes
Bonfond, Bertrand ULg

Scientific conference (2011, December 08)

Depuis les premières détections d'émissions aurorales par les sondes Voyager à la fin des années 70, nos connaissances des aurores de Jupiter et de Saturne ont considérablement progressé. Je présenterai ... [more ▼]

Depuis les premières détections d'émissions aurorales par les sondes Voyager à la fin des années 70, nos connaissances des aurores de Jupiter et de Saturne ont considérablement progressé. Je présenterai ici quelques uns des derniers résultats obtenus à l'aide du télescope spatial Hubble et de la sonde Cassini en orbite autour de Saturne. Ces images acquises dans le domaine ultraviolet révèlent une complexité que l'on commence seulement à appréhender. Assemblées en séquences, elles dévoilent une dynamique surprenante. Flashs, pulsations, expansions, contractions, apparitions, disparitions, fusions, séparations et mouvements relatifs de structures étendues sur des dizaines de milliers de kilomètres ou localisés sur quelques centaines de kilomètres : la diversité des comportements que nous observons est le témoignage de la richesse des processus en œuvre dans les magnétosphères de Jupiter et Saturne. Lunes exotiques, volcans et geysers colossaux, champs magnétiques gigantesques et rotations planétaires rapides sont les ingrédients de ce surprenant laboratoire de physique des plasmas. [less ▲]

Detailed reference viewed: 19 (7 ULg)
See detailAurores, les lumières atmosphériques
Nazé, Yaël ULg

Article for general public (2009)

Not Available

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailAuschwitz – ein Symbol?
Pontzen, Alexandra ULg

in Literaturkritik.de (2009)

Detailed reference viewed: 18 (1 ULg)