Western Australia's superb skies made it possible:

Chromosphere, corona sighted during annular solar eclipse!

Annular eclipses of the Sun can be for more than just the 'special cases' of partial ones that they're so often treated as: Astrophotographers willing to push the envelope could learn that at the eclipse of February 16, 1999, in Western Australia, when almost the full range of phenomena usually associated with total solar eclipses could be recorded with simple photographic equipment. The skies couldn't have been better: A deep blue had greeted the perhaps one thousand eclipse travellers would had converged near the coast of WA, South of the little town of Geraldton, some 400 km North of Perth. This was to be place where the zone of annularity, only 40 km wide, would be particularly well accessible (thanks to a well-maintained highway running up the coast), where the weather prospects were best - and where the ring of remaining sunlight would be slimmer than anywhere else where annularity would make landfall.

While several hundred observers had moved to the center line, hundreds more had met near the village of Greenough where a famous pub, the Hampton Arms Inn, would become the center of the astronomical world for a few hours. From here, close to the Northern limit of the annularity zone, a 'live' Internet broadcast was staged. And several Australian TV stations had set up equipment for real live transmissions (the few minutes of eclipse CNN broadcast around the world actually originated from one of these feeds). There was only one worry: Would the eclipse be annular here at all, or would the fiery ring always stay broken in one place or another?

The two leading eclipse prediction specialists had posted conflicting coordinates for the limit line on their websites and hadn't bothered to reconcile the numbers. By one calculation Greenough would see a complete ring of fire, by the other it would be a borderline case. But why go to the edge at all? It was not just the convenience of the pub in an otherwise very sparsely populated, hot dry landscape: In contrast to total eclipses, where one usually wants to experience as long a totality - and see the elusive corona - as possible, annular eclipses tend to be more interesting near the limits. Various optical phenomena are more pronounced than on the center line, in particular the coming and going of Baily's Beads, when the ragged lunar limb cuts the remaining crescent of the solar photosphere into an ever-changing pattern of 'light pearls'. And we wanted even more...

In order to get both a complete ring for a few seconds (mainly for aesthetic reasons) and to maximize the geometrical effects, we - three German amateurs - moved a few kilometers to the South, deeper into the zone of annularity but still shy of the center line. The first partial phase had already begun, and soon the planets Venus and later Jupiter could be spotted with the naked eye to the upper right of the shrinking crescent of the Sun. Never during partiality and annularity, though, was it possible to look at the Sun directly without a filter: Even the thin ring that finally greeted us, was still way too bright. So all the detailled observations had to be done with optical aid, in my case a 500 mm telephoto lens with a x2 teleextender and a varying number of layers of a solar filter foil: First two layers (for the early partial phases), then only one, when the crescent had become so slim that we were only seeing the limb-darkened outer few arc seconds of the solar disk.

Now Baily's Beads were spectacular in the viewfinder: How the Moon cut into the Sun yet couldn't cover it fully, how the two cusps of the thin solar crescent raced towards each other and finally merged was a breathtaking and very fast spectacle that easily competes with the final moments before a total eclipse begins. For the next seconds, though, things are reversed: The actual annularity is the most boring phase of an annular eclipse (it's just a dazzling bright ring in the sky, so what?) which gets more interesting again when the Moon's limb touches the Sun's the 2nd time and cuts the ring again.. And when it had just done so, with several Baily's Beads left hovering between the newly-formed cusps, I removed the last layer of solar filter as well.

Now it was no longer possible to look into the viewfinder, of course, but the optics were just perfect to capture on film something few observers of annular eclipses ever go for: the chromosphere of the Sun, the bright red layer just above the photosphere. As I snapped away (with 1/1000 of a second exposure at about f/20 on ISO 100 color slide film), an amazing sequence of pictures was recorded, showing the chromosphere and several prominences while Baily's Beads faded and disappeared. Then the chromosphere itself was cut into segments by the advancing lunar limb, and soon most of it was covered as well. The glaring solar crescent just arc minutes away was not nearly bright enough to disturb the view- and there was still more to come: When the Moon had covered the chromosphere it was obvious that there was something else behind it - the inner corona! Who needs total eclipses...

By Daniel Fischer - here are more pictures!