Periodicity of Auroras

Saturn’s equinoctial auroras

[1] We present the first images of Saturn’s conjugate equinoctial auroras, obtained in early 2009 using the Hubble Space Telescope. We show that the radius of the northern auroral oval is 1.5 smaller than the southern, indicating that Saturn’s polar ionospheric magnetic field, measured for the first time in the ionosphere, is 17% larger in the north than the south. Despite this, the total emitt...

Inferences concerning Auroras.

shown in the seventh column of the table is little affected by differences in the limiting brightness. This divergence indicates that, as compared with both Kapteyn and Mount Wilson, their results are not homogeneous; and noting, further, that the numerous and careful guages of the Herschels which extend to the 14th magnitude give a galactic condensation agreeing closely with Kapteyn (Herschel ...

Determining the Skeletons of the Auroras

The auroral emissions observed in the high-latitude regions encircling the magnetic poles are a key element in studying plasmaphysical processes in the near-Earth space, the magnetosphere. The Finnish Meteorological Institute operates five digital all-sky cameras, which routinely monitor the auroral emissions in Northern Finland, Sweden, and Svalbard; each camera records an image of the full sk...

Juno‐UVS approach observations of Jupiter's auroras

Juno ultraviolet spectrograph (UVS) observations of Jupiter's aurora obtained during approach are presented. Prior to the bow shock crossing on 24 June 2016, the Juno approach provided a rare opportunity to correlate local solar wind conditions with Jovian auroral emissions. Some of Jupiter's auroral emissions are expected to be controlled or modified by local solar wind conditions. Here we com...

Periodicity and Almost-periodicity