Observations by Daniel Fischer
Here’s the answer to a question that has come up several times on this and other lists since the Great Australian Annular eclipse one month ago: Was it possible to see and photograph the chromosphere?
It was! And it was surprisingly easy. Some preliminary images can be seen now at
http://www.astro.uni-bonn.de/~dfischer/aus99/first.html
First three filtered pictures of the ring phase itself, followed by another three taken without any filter. The outstandingly clear sky conditions of Greenough helped a lot, of course, but I’m still amazed how little scattered light from the photosphere is present.
The chromosphere is brilliant, some – minor – prominences can be seen and even a hint of the inner corona (which is much more evident in the original slides). All this minutes after annularity, with a brilliant and steadily growing photospheric crescent close-by.
And the pictures were taken with the most primitive of optics: a 500 mm telephoto lens (bought for $ 50.- at a German astronomy market) with an old teleextender (bought for another $ 50.- in Perth, days before the eclipse).
So far I’ve seen one other similarly successful attempt to get the chromosphere from the Feb. 99 eclipse – and there even a video camera had been used (http://www.astromag.co.uk/eclipse.html). The observing site was different, so different parts of the chromosphere were sampled.
By the way: Without knowing about previous successes of getting the chromosphere during annular eclipses (with even wider rings and under adverse sky conditions), I surely wouldn’t have tried. Thanks to Freddy Dorst for leading the way at an eclipse in Peru some years back!
Daniel Fischer, Germany