Aurora auroras is that an as-yet-undetected body around the dwarf star is throwing off material, as is the case with Jupiter and its moon Io. [[Category:Space plasmas]] [[Category:Arctic geography terminology]] [[Category:Atmospheric optical phenomena]] [[Category:Earth phenomena]] [[Category:Electrical phenomena]] [[Category:Light sources]] [[Category:Plasma physics]] [[Category:Planetary science]] [[Category:Sources of electromagnetic interference]] [[Category:Articles containing video clips]] Aurora An aurora (plural: auroras or aurorae), sometimes referred to as polar lights, northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in the Earth's sky, predominantly seen in the high-latitude regions (around the Arctic and Antarctic). Auroras are produced when the magnetosphere is sufficiently
R Coronae Borealis variable R Coronae Borealis variable An R Coronae Borealis variable (abbreviated RCB, R CrB) is an eruptive variable star that varies in luminosity in two modes, one low amplitude pulsation (a few tenths of a magnitude), and one irregular, unpredictably-sudden fading by 1 to 9 magnitudes. The prototype star R Coronae Borealis was discovered by the English amateur astronomer Edward Pigott in 1795, who first observed the enigmatic fadings of the star. Only about 150 RCB stars are currently known in our Galaxy while up to 1000 were expected, making this class a very rare kind of star. It is increasingly