[Chromospheric Spectrum] Eclipse '99

Slitless spectrum of chromosphere/corona showing hydrogen and helium recombination and collisionally ionized iron emission lines. Click on image to go directly to the spectroscopic results.

The 11 August 1999 total solar eclipse was seen from a small farm complex called Wolfersberg in open fields some 20km ESE of the centre of Munich. It was chosen to be within the 2min band of totality but likely to be relatively unpopulated.

There were intermittent views of the Sun between first and second contact with quite a heavy rainshower which stopped 9min before totality. A large clear patch of sky revealed a perfect view of the Sun just 2min before second contact and it remained clear for at least half an hour after third contact. During totality, the corona could be seen to between 2 and 3 solar radii with the naked eye. It showed a remarkable radial structure. Pink chromospheric emission could be seen around most of the circumference and there were several prominences, in particular a bright one to the south. Mercury and Venus could be seen and the horizon to the south was quite bright. The clear horizon could be seen between the trunks of a band of trees, producing a quite peculiar effect of low illumination. At 3rd contact, a few whisps of iridescent cloud appeared right next to the rapidly brightening Sun with the colours showing more intensely than normally seen when dazzled by the full brightness.

The principal project was to photograph the spectrum of the chromosphere during totality using a transmission grating in front of a moderate telephoto lens. The desire to do this was stimulated by a view of the 1976 eclipse in Australia when I held the same grating up to the eclipsed Sun and was thrilled by the view of the emission line spectrum. The trick now was to get the exposure right! The results of this and other photography are given below.

  1. Chromospheric spectra
  2. Other images

The poster

An Eclipse Poster has been constructed using images and spectra from people at and connected with ESO. The acknowledgments are contained in the poster itself. The main file is in PDF (Adobe Acrobat V3 compatible) and is suitable for printing up to A3 size. It is large (5.2MB)! A smaller jpeg version is available by clicking the thumbnail.

The crew: Trish, Andrew and Emma Fosbury and Roger Wood in the cloud and rain between first and second contact.

crew-1 crew-3
crew-4 crew-5

Last update: 24 August 1999: Mail to rfosbury@eso.org
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