Daily Image
09-12-2021
Colloquium: Aurorae – the faintest and the brightest: from Ganymede to Brown Dwarfs
| Submitter: | Joachim Saur |
| Description: | Aurorae are, both, beautiful and highly diagnostics phenomena about planets and dwarfs. They are effectively the only means to probe the space plasma environment around planetary bodies by remote sensing with observations at wavelengths ranging from X-ray to the radio. The image here shows Jupiter's infrared aurorae observed by the Juno spacecraft. In this talk, I review the current knowledge about aurorae on planets, moons, and dwarfs. Next to Earth, I will focus on the latest discoveries of NASA’s Juno spacecraft on the mighty aurorae of Jupiter and the 5 orders of magnitude dimmer aurora of Jupiter’s moon Ganymede. We then transfer this knowledge to extrasolar planets and brown dwarfs. We show that brown dwarfs are ideal objects to search for aurora outside the solar system, particularly in the UV, with an expected brightness easily more than 6 orders of magnitude larger than the one of Jupiter. Based on HST observations, we present tentative evidence for auroral UV emission from T-dwarf 2MASS J1237+6526. Remote sensing of aurorae outside the solar system paves the way for the emerging field of extrasolar space plasma physics. |
| Copyright: | CC-BY-SA (Credit: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM) |
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