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Panorama of the Aurora 4/2000 above Göttingen

Date:7.4.2000 Time:approx. 0 UT Exposure:2x about 30s
Field:155o x 70o Emulsion:Kodak Royal Gold 1000 Filter:none
Optics:f=17mm, 1/3.5 Place:Gross-Schneen, Göttingen Observer:T. Credner & E. Vorlaufer

© Copyright by the Observers

Shown is a mosaic of two wide angle images giving a 155 degree panorama of the great Aurora display of April 2000. It resembles nicely the overall visual appearance of this event.

At lower altitudes (up to 110km) the usual green light of wavelength 557.7 nm by excited oxygen dominates. Above, in the altitude range of 200 - 400 km, the excited oxygen glows red. This red emission can't occur at lower altitude since the atmospheric density is too high. For the red emmission the oxygen needs quite a long time to stay in the excited state. But in the dense lower atmosphere the oxygen looses this energy already by encounters with other particles before the red emission might occur.