deutsch english español language

The Chromosphere at the third contact of the Solar Eclipse 8/99

Date:11.08.1999 Time:9:32 UT Exposure:1/125s
Field of View:0.32o x 0.46o Emulsion:Kodachrome 64 Filter:none
Instrument:f=1000mm, 1/10 Place:Altroff, France Observer:T. Credner

© Copyright by the observers

At the beginning and end of totality of a solar eclipse (the so called second and third contacts) the solar chromosphere becomes visible. The name comes from its colorful appearance and the different colored emission lines in its spectrum. The main optical emission is the red H-alpha line of ionized hydrogen (656 nm). The thickness of this atmospheric layer is about 12000 km. However, a lot of turbulences occur which give this layer a non uniform appearance. So called spicules give a small ripple of the chromosphere, whereas the larger prominences can loft the ionized gas high above the usual level.

A. Unsöld, Physik der Sternatmosphären, Springer Verlag