Aurora elders from watching or interpreting the messages of ancestors they believed were transmitted through an aurora. "[[Bulfinch's Mythology]]" relates that in [[Norse mythology]], the armour of the [[Valkyrie|Valkyrior]] "sheds a strange flickering light, which flashes up over the northern skies, making what Men call the 'aurora borealis', or 'Northern Lights' ". There appears to be no evidence in [[Old Norse literature]] to substantiate this assertion. The first Old Norse account of "norðrljós" is found in the Norwegian chronicle "[[Konungs Skuggsjá]]" from AD 1230. The chronicler has heard about this phenomenon from compatriots returning from [[Greenland]], and he gives three possible
Sigma Coronae Borealis σ CrB is an RS Canum Venaticorum variable. It varies in brightness by 0.05 magnitudes every 1.139789 days, the same as the orbital period. The brightness changes are caused by variations in surface brightness on the stars, effectively giant sunspots. Variable star designations are not given to stars with Bayer designations, but in this case only one component of σ Coronae Borealis is identified as variable, so it has the designation TZ Coronae Borealis. Sigma Coronae Borealis Sigma Coronae Borealis (σ CrB) is a star system in the constellation of Corona Borealis. It is a quintuple star system containing three