Annular Eclipse in Panama
8 April 2005

by Mike Simmons

For those of us who couldn't afford to be on one of the ships meeting the Moon's shadow for a view of totality in the south Pacific, the annular phase of this rare hybrid eclipse (both total and annular) was our only option. I led 21 eclipse hopefuls to Panama on a tour organized by US-based Astronomy Vacations. This was supposed to be the dry season in Panama but the warm ocean condition known as El Nino had been bringing plenty of clouds and rain to our observing site near Panama's Pacific coast. We stayed at a beach resort 90 minutes drive south of the capital city of Panama and just 30 minutes from our planned observing site. This site and a backup site in the event of poor weather were chosen and prepared by members of the Association of Panamanian Amateur Astronomers. But the clouds and rain we experienced during our first few days in Panama did not bode well for seeing the eclipse from anywhere in the region.

The magnitude of the annular eclipse we hoped to see would be more than 99%, leaving a very thin ring of sunlight around the Moon at mid-eclipse. An annular eclipse of this magnitude is rare and no one was certain what to expect. Would the ring of sunlight around the Moon's silhouette be a bright white ring as seen in lower magnitude annular eclipses when the Moon's diameter is very much less than the Sun's? Or would we see the red light of the chromosphere, the region of gases just above the Sun's visible "surface" but too faint to see under normal circumstances? Talk of Bailey's beads - points of light shining through lunar valleys along the Moon's edge - dominated our conversations.
Poor weather and last-minute maneuvering are all part of eclipse chasing and we were prepared and hoping for the best. That optimism was rewarded when the morning of the eclipse brought the first patches of blue sky we had seen. The glimpse of the Sun seemed to melt away the gloominess of the previous night's forecast. I visited a town near our observing site in the morning and learned more about the local weather conditions from our Panamanian hosts. We were all cautiously optimistic. Returning to our hotel I found the conditions highly variable along the highway, leaving the possibility of patchy, moving clouds and a last-minute dash to clear sky as the eclipse progressed. We decided to stick with the primary observing site but to retain the option of moving if weather prospects elsewhere looked more promising.

Two buses took our group to the observing site, a small airport that had been closed for the afternoon for the benefit of eclipse observers. The Panamanians' preparations were flawless and there was ample space for everyone. The first bus arrived well before the eclipse to allow those with equipment to set up before first contact when the Moon begins its slide across the Sun. The weather seemed promising but the second bus that brought visual observers to the site just before first contact reported driving through a rainstorm on the way!
Photographers start their sequences in bad weather early in the eclipse.
First contact was visible through thin high clouds - the long-anticipated eclipse had begun! Optimism and excitement increased as the eclipse progressed. Photographers were getting their first eclipse images although they had to recalculate exposures for their critical shots to account for the light lost in the thin clouds. We could see that the variable clouds would never clear completely but it seemed the Sun might slip into the thinnest area of clouds for the critical central phase - the 16 seconds when the Moon's silhouette would be entirely within the Sun's disk. For locals who had planned for years, and visitors who had traveled from around the world, the clouds movement now meant the difference between success and failure. Mere seconds before second contact - the beginning of the central annular phase - the Sun brightened as the clouds thinned, allowing the clearest view yet. A cheer from the crowd announced second contact as the tips of the spreading arc of light at the Sun's edge connected to form a complete ring. The Moon's motion across the Sun was easily visible and beads that formed disappeared quickly. I used Leica 10x42 binoculars with Baader filter material and was able to see the red light of the chromosphere in the smallest beads. The photographers around me were too intent on their programs during this very short eclipse to see such details. Their efforts were rewarded with some fabulous images and video, though, some of which was viewed by everyone just moments later.
Photographers beginning capturing the eclipse in still and video images.
The end of the eclipse occurred just minutes before sunset but a distant thunderstorm spread across the horizon and obscured the Sun well before then. Some photographers were disappointed to miss the end of their sequences but for most of us the later stages of the eclipse were a time to relax. We packed up our equipment and headed back to the hotel for a celebratory dinner followed by eclipse video viewing. The next day we boarded buses for the return to the airport and our flights home to the US, Germany, the Netherlands and Japan. The trip had been a success not only for the eclipse but also in bringing people from around the world together as friends. The talk that morning was not about the previous day's eclipse but plans for the next one in 2006. I expect to see some old friends and make new ones in the Moon's shadow again next year.
Two photographers planning to capture the entire eclipse.

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