Alternating North‐South Brightness Ratio of Ganymede's Auroral Ovals: Hubble Space Telescope Observations Around the Juno PJ34 Flyby

Saur, Joachim; Duling, Stefan; Wennmacher, Alexandre; Willmes, Clarissa; Roth, Lorenz; Strobel, Darrell F.; Allegrini, Frédéric; Bagenal, Fran; Bolton, Scott J.; Bonfond, Bertrand; Clark, George; Gladstone, Randy; Greathouse, Thomas K.; Grodent, Denis; Hansen, Candice J.; Kurth, William S.; Orton, Glenn S.; Retherford, Kurt D.; Rymer, Abigail M.; Sulaiman, Ali H.

doi:10.1029/2022gl098600

Article (Scientific journals)

Alternating North‐South Brightness Ratio of Ganymede's Auroral Ovals: Hubble Space Telescope Observations Around the Juno PJ34 Flyby

Saur, Joachim; Duling, Stefan; Wennmacher, Alexandre et al.

2022 • In Geophysical Research Letters, 49 (23)

Peer Reviewed verified by ORBi

Permalink
https://hdl.handle.net/2268/297338

DOI
10.1029/2022gl098600

Files (2)Send to Details Statistics Bibliography Similar publications

Files

Full Text

Saur et al. - 2022 - Alternating North-South Brightness Ratio of Ganyme.pdf

Publisher postprint (1.06 MB)

Creative Commons License - Attribution, Non-Commercial

Download

Annexes

2022gl098600-sup-0001-supporting information si-s01.pdf

(73.73 kB)

Download

All documents in ORBi are protected by a user license.

Send to

RIS BibTex APA Chicago Permalink X Linkedin

Details

Keywords :

General Earth and Planetary Sciences; Geophysics; Ganymede; Juno; Jupiter; Hubble Space Telescope; aurora

Abstract :

[en] We report results of Hubble Space Telescope observations from Ganymede's orbitally trailing side which were taken around the flyby of the Juno spacecraft on 7 June 2021. We find that Ganymede's northern and southern auroral ovals alternate in brightness such that the oval facing Jupiter's magnetospheric plasma sheet is brighter than the other one. This suggests that the generator that powers Ganymede's aurora is the momentum of the Jovian plasma sheet north and south of Ganymede's magnetosphere. Magnetic coupling of Ganymede to the plasma sheet above and below the moon causes asymmetric magnetic stresses and electromagnetic energy fluxes ultimately powering the auroral acceleration process. No clear statistically significant timevariability of the auroral emission on short time scales of 100s could be resolved. We show that electron energy fluxes of several tens of mW m−2 are required for its OI 1,356 Å emission making Ganymede a very poor auroral emitter.

Research Center/Unit :

STAR - Space sciences, Technologies and Astrophysics Research - ULiège

Disciplines :

Space science, astronomy & astrophysics

Author, co-author :

Saur, Joachim ; Institute of Geophysics and Meteorology University of Cologne Cologne Germany

Duling, Stefan ; Institute of Geophysics and Meteorology University of Cologne Cologne Germany

Wennmacher, Alexandre ; Institute of Geophysics and Meteorology University of Cologne Cologne Germany

Willmes, Clarissa ; Institute of Geophysics and Meteorology University of Cologne Cologne Germany

Roth, Lorenz ; School of Electrical Engineering KTH, Royal Institute of Technology Stockholm Sweden

Strobel, Darrell F. ; Johns Hopkins University Baltimore MD USA

Allegrini, Frédéric ; Southwest Research Institute San Antonio TX USA ; Department of Physics and Astronomy University of Texas at San Antonio San Antonio TX USA

Bagenal, Fran ; University of Colorado Boulder CO USA

Bolton, Scott J. ; Southwest Research Institute San Antonio TX USA

Bonfond, Bertrand ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)

More authors (10 more)

Language :

English

Title :

Alternating North‐South Brightness Ratio of Ganymede's Auroral Ovals: Hubble Space Telescope Observations Around the Juno PJ34 Flyby

Publication date :

12 December 2022

Journal title :

Geophysical Research Letters

ISSN :

0094-8276

eISSN :

1944-8007

Publisher :

American Geophysical Union (AGU)

Volume :

Issue :

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GL098600

Funders :

F.R.S.-FNRS - Fonds de la Recherche Scientifique

Available on ORBi :

since 14 December 2022

Statistics

Number of views

36 (0 by ULiège)

Number of downloads

40 (0 by ULiège)

More statistics

Scopus citations^®

Scopus citations^®
without self-citations

OpenCitations

OpenAlex citations

Bibliography

Allegrini, F., Bagenal, F., Ebert, R. W., Louarn, P., McComas, D. J., Szalay, J. R., et al. (2022). Plasma observations during the 7 June 2021 Ganymede flyby from the Jovian Auroral Distributions Experiment (JADE) on Juno. Geophysical Research Letters, 49, e2022GL098682. https://doi.org/10.1029/2022GL098682
Bagenal, F., & Delamere, P. A. (2011). Flow of mass and energy in the magnetospheres of Jupiter and Saturn. Journal of Geophysical Research, 116(A5), A05209. https://doi.org/10.1029/2010JA016294
Bhardwaj, A., & Gladstone, G. R. (2000). Auroral emissions of the giant planets. Review of Geophysics, 38(3), 295–353.
Clark, G., Kollmann, P., Mauk, B. H., Paranicas, C., Haggerty, D., Rymer, A., et al. (2022). Energetic charged particle observations during Juno’s close flyby of Ganymede. Geophysical Research Letters, 49, e2022GL098572. https://doi.org/10.1029/2022GL098572
Connerney, J. E. P., Acuna, M. H., Ness, N. F., & Satoh, T. (1998). New models of Jupiter’s magnetic field constrained by the Io flux tube footprint. Journal of Geophysical Research, 103(A6), 11929–11939. https://doi.org/10.1029/97ja03726
Dessler, A. J. (1983). Physics of the Jovian magnetosphere. Cambridge University Press.
Duling, S., Kurth, W. S., Sulaiman, A. H., Mauk, B. H., Bolton, S. J., & Louis, S. (2022). Ganymede MHD model: Magnetospheric context for Juno’s PJ34 flyby. Geophysics Research Letters, 49, e2022GL101688. https://doi.org/10.1029/2022GL101688
Duling, S., Saur, J., & Wicht, J. (2014). Consistent boundary conditions at nonconducting surfaces of planetary bodies: Applications in a new Ganymede MHD model. Journal of Geophysical Research, 119(6), 4412–4440. https://doi.org/10.1002/2013JA019554
Eviatar, A., Strobel, D. F., Wolfven, B. C., Feldman, P., McGrath, M. A., & Williams, D. J. (2001). Excitation of the Ganymede ultraviolet aurora. The Astrophysical Journal, 555(2), 1013–1019. https://doi.org/10.1086/321510
Feldman, P. D., McGrath, M. A., Strobel, D. F., Moos, H. W., Retherford, K. D., & Wolven, B. C. (2000). HST/STIS ultraviolet imaging of polar aurora on Ganymede. The Astrophysical Journal, 555(2), 1085–1090. https://doi.org/10.1086/308889
Grasset, O., Dougherty, M. K., Coustenis, A., Bunce, E. J., Erd, C., Titov, D., et al. (2013). JUpiter ICy moons Explorer (JUICE): An ESA mission to orbit Ganymede and to characterise the Jupiter system. Planetary and Space Science, 78, 1–21. https://doi.org/10.1016/j.pss.2012.12.002
Greathouse, T., Gladstone, R., Molyneux, P., Versteeg, M., Hue, V., Kammer, J., et al. (2022). UVS observations of Ganymede’s aurora during Juno orbits 34 and 35. Geophysic Research Letters, 49, e2022GL099794. https://doi.org/10.1029/2022GL099794
Gustin, J., Grodent, D., Ray, L. C., Bonfond, B., Bunce, E. J., Nichols, J. D., & Ozak, N. (2016). Characteristics of north jovian aurora from STIS FUV spectral images. Icarus, 268, 215–241. https://doi.org/10.1016/j.icarus.2015.12.048
Hall, D. T., Feldman, P. D., McGrath, M. A., & Strobel, D. F. (1998). The far-ultraviolet oxygen airglow of Europa and Ganymede. The Astrophysical Journal, 499(5), 475–481. https://doi.org/10.1086/305604
Jia, X., Walker, R., Kivelson, M., Khurana, K., & Linker, J. (2008). Three-dimensional MHD simulations of Ganymede’s magnetosphere. Journal of Geophysical Research, 113, A06212.
Kivelson, M. G., Khurana, K. K., Walker, R. J., Russell, C. T., Linker, J. A., Southwood, D. J., & Polanskey, C. (1996). A magnetic signature at Io: Initial report from the Galileo magnetometer. Science, 273, 337–340.
Kivelson, M. G., Warnecke, J., Bennett, L., Joy, S., Khurana, K. K., Linker, J. A., et al. (1998). Ganymede’s magnetosphere: Magnetometer overview. Journal of Geophysical Research, 103(E9), 19963–19972. https://doi.org/10.1029/98JE00227
Mauk, B. H., Haggerty, D. K., Paranicas, C., Clark, G., Kollmann, P., Rymer, A. M., et al. (2017). Juno observations of energetic charged particles over Jupiter’s polar regions: Analysis of monodirectional and bidirectional electron beams. Geophysical Research Letters, 44(10), 4410–4418. https://doi.org/10.1002/2016GL072286
McGrath, M. A., Jia, X., Retherford, K. D., Feldman, P. D., Strobel, D. F., & Saur, J. (2013). Aurora on Ganymede. Journal of Geophysical Research, 118(5), 2043–2054. https://doi.org/10.1002/jgra.50122
Musacchio, F., Saur, J., Roth, L., Retherford, K. D., McGrath, M. A., Feldman, P. D., & Strobel, D. F. (2017). Morphology of Ganymede’s FUV auroral ovals. Journal of Geophysical Research, 122(3), 2855–2876. https://doi.org/10.1002/2016JA023220
Neubauer, F. M. (1980). Nonlinear standing Alfvén wave current system at Io: Theory. Journal of Geophysical Research, 85(A3), 1171–1178. https://doi.org/10.1029/ja085ia03p01171
Neubauer, F. M. (1998). The sub-Alfvénic interaction of the Galilean satellites with the Jovian magnetosphere. Journal of Geophysical Research, 103(E9), 19843–19866. https://doi.org/10.1029/97je03370
Retherford, K. D., Moos, H. W., & Strobel, D. F. (2003). Io’s auroral limb glow: Hubble Space Telescope FUV observations. Journal of Geophysical Research, 108(A8), 1333. https://doi.org/10.1029/2002JA009710
Roth, L., Ivchenko, N., Gladstone, G. R., Saur, J., Grodent, D., Bonfond, B., & Retherford, K. D. (2021). A sublimated water atmosphere on Ganymede detected from Hubble Space Telescope observations. Nature Astronomy, 5(10), 1043–1051. https://doi.org/10.1038/s41550-021-01426-9
Roth, L., Saur, J., Retherford, K. D., Feldman, P. D., & Strobel, D. F. (2014). A phenomenological model of Io’s UV aurora based on HST/STIS observations. Icarus, 228, 386–406. https://doi.org/10.1016/j.icarus.2013.10.009
Roth, L., Saur, J., Retherford, K. D., Strobel, D. F., Feldman, P. D., McGrath, M. A., et al. (2016). Europa’s far ultraviolet oxygen aurora from a comprehensive set of HST observations. Journal of Geophysical Research, 121(3), 2143–2170. https://doi.org/10.1002/2015JA022073
Saur, J., Duling, S., Roth, L., Jia, X., Strobel, D. F., Feldman, P. D., et al. (2015). The search for a subsurface ocean in Ganymede with Hubble Space Telescope observations of its auroral ovals. Journal of Geophysical Research, 120(3), 1715–1737. https://doi.org/10.1002/2014JA020778
Saur, J., Grambusch, T., Duling, S., Neubauer, F. M., & Simon, S. (2013). Magnetic energy fluxes in sub-Alfvénic planet star and moon planet interactions. Astronomy & Astrophysics, 552, A119. https://doi.org/10.1051/0004-6361/201118179
Saur, J., Janser, S., Schreiner, A., Clark, G., Mauk, B. H., Kollmann, P., et al. (2018). Wave-particle interaction of Alfvén waves in Jupiter’s magnetosphere: Auroral and magnetospheric particle acceleration. Journal of Geophysical Research, 123(11), 9560–9573. https://doi.org/10.1029/2018JA025948
Saur, J., Willmes, C., Fischer, C., Wennmacher, A., Roth, L., Youngblood, A., & Reiners, A. (2021). Brown dwarfs as ideal candidates for detecting UV aurora outside the Solar System: Hubble Space Telescope observations of 2MASS J1237+6526. Astronomy & Astrophysics, 655, A75. https://doi.org/10.1051/0004-6361/202040230
Bevington, P. R., & Robinson, D. K. (2003). Data reduction and error analysis for the physical sciences. McGraw Hill.
Hall, D. T., Strobel, D. F., Feldman, P. D., McGrath, M. A., & Weaver, H. A. (1995). Detection of an oxygen atmosphere on Jupiter’s moon Europa. Nature, 373(6516), 677–679. https://doi.org/10.1038/373677a0
Kanik, I., Norem, C., Makarov, O., Palle, P. V., Ajello, J., & Shemansky, D. (2003). Absolute emission cross sections of OI (130.4 nm) and OI (135.6 nm). Journal of Geophysical Research, 108(E11), 5126. https://doi.org/10.1029/2000je001423