A total solar eclipse is perhaps the most wonderful sight Nature affords to us here on Earth. Very few people get the opportunity to see this remarkable phenomenon in a lifetime since the band on the Earth's surface within which a total eclipse is visible is usually so narrow that it rarely passes through highly populated areas like cities or large towns. The August 11, 1999 eclipse, the last of the Second Millennium, was an extraordinary exception - the path of totality passed right through some of the most densely populated areas of the world, including Europe, the middle East and the Indian subcontinent.

The 1999 eclipse was a great challenge to Bulgarian scientists. In November 1997 the Executive Council of the Bulgarian Academy of Sciences (BAS) appointed a national council to coordinate the many scientific research projects expected to be conducted during the eclipse in the path of totality through Bulgaria. In the event, with very favourable weather conditions, highly successful observations and measurements were carried out by several research institutes in Bulgaria, including the Institute of Astronomy, the Solar-Terrestrial Influences Laboratory, the Institute of Electronics, the Geophysical Institute, and the National Institute of Meteorology and Hydrology, all within the Bulgarian Academy of Sciences, the Department of Physics at the Sofia University and the Bulgarian National Astronomical Observatories. The proposed scientific programme met with general approval and support of the international scientific community, proof of which is the fact that Bulgarian scientists were joined by teams from the United Kingdom, Russia, Poland, Romania, United States, Ukraine, Greece, Japan and several other countries. A particularly ambitious experiment was carried on board a military aircraft which flew along the path of totality over Bulgarian territory, so extending the duration of totality significantly.

Here is a list of some of the chief scientific experiments conducted in Bulgaria during the eclipse:

• Obtaining series of coronal and prominence images and spectra with a variety of exposures using photographic film;
• obtaining coronal images through polarization filters;
• Obtaining series of coronal spectrograms covering a variety of spectral ranges;
• Obtaining spectral and colorimetric data about atmosphere irradiance;
• Exploring the status of the terrestrial ozone layer and ionosphere;
• Performing biological and medical observations and experiments.

These experiments were planned by Bulgarian scientists but as it turned out scientists from other countries were also interested in doing similar things so that there was a lot of complementarity.

The most appropriate location for the experiments was only decided after a careful enquiry into past meteorological conditions stretching back over a hundred years. In the end it was decided to set up observation sites in the region of the small town of Shabla on the Black Sea coast, located almost exactly along the middle of the totality track. Shabla had the highest probability of cloudless conditions for mid-August. It also offered reasonably good communications facilities which were needed for preparations before the eclipse and electrical power supply.

In the event, August 11 turned out to be an ideal day for eclipse observing from Shabla. Those gathered there were rewarded with a spectacular view in weather conditions that can only be described as near-perfect – cloudless, windless, and a highly transparent atmosphere. This was indeed lucky as there was a violent thunderstorm just a few hours later that threatened to dampen the spirits of the scientists who were transported to the nearby city of Albena for some excellent entertainment to celebrate the occasion put on by the local organising committee. As was learned after the event, observers in Bulgaria and Romania were among the few in Europe who had such a favourable weather – anywhere west of Romania along the totality track was dogged by total or near-total cloud cover.

Help and support for participating scientists were generously given by the BAS Board, the Bulgarian Ministry of Defence, MobilTel JSC, and the Optela Ltd. Company. National observatories in Bulgaria were also involved in the eclipse preparations and observations, notably those at Haskovo, Dimitrovgrad, Smolian, and Stara Zagora. This added a great deal to the success of the experiments carried out. It was especially gratifying that so many young people in Bulgaria played a significant role in the eclipse experiments and observations. Children and students from a large number of local schools and colleges were involved in getting some highly impressive results and images.

To commemorate the successful observations carried out during the 1999 eclipse, scientific and local organising committees were appointed to set up an International Conference entitled "First Results of 1999 Total Eclipse Observations" which was held on September 11-15, 2000 in Varna, approximately one year after the eclipse. The scientific committee consisted of scientists with international reputation and included Prof. Vladimir Dermendjiev and Academician Dimitar Mishev (Bulgaria), Prof. Ken Phillips (United Kingdom), Prof. B. Rompolt (Poland), Dr. P. Rudawy (Poland), Prof. I. S. Kim (Russia), Prof. R. Gulyaev (Russia), Prof. V. Rusin (Slovak Republic), Prof. M. Rybanski (Slovak Republic) and Prof. A. Okten (Turkey). Some fifty people expressed an interest in participating in the conference, including 17 from outside Bulgaria. The conference programme included 9 plenary sessions, 4 scientific sessions and one poster session. World recognized astrophysicists were among the plenary session chairmen. The entire conference was conducted in English, which was quite a challenge for nearly all participants who came from several European, non-English-speaking countries, but everyone managed extremely well. The scientific contributions were often illustrated by highly spectacular images of the corona and prominences during eclipse totality, some of which, taken by some young astronomers from Haskovo in Bulgaria, were on display during the conference. They provoked a lot of discussion among the participants.

The Conference was well covered by the media, including Bulgarian national television, local cable television stations, radio and a number of national and local newspapers – their reporters interviewed a number of conference participants. The District Governor for the Varna District, Prof. Dr. Nikolai Pantev, honoured the Conference by giving the opening speech. The whole Conference was financially supported by the BAS Board and the Evrika Foundation, which is a non-governmental body encouraging scientific creativity in young people in Bulgaria.

Only a few months after the Conference was held, Prof. Dr Vladimir Dermendjiev who was the leading light of the Conference organisation and chair of the Scientific Organising Committee, tragically died to the immense shock to his colleagues and friends worldwide. The world of astronomy lost a truly great scientist and organizer as well as a devoted and sensitive human being. He was the Secretary of the National Council for Research Coordination for the 1999 eclipse and provided enormous amounts of help during the eclipse to the many scientists present. These Proceedings of the "First Results of 1999 Total Eclipse Observations" are dedicated to his memory by his grateful colleagues who participated in the conference. It is a fitting tribute to this very great man who touched the lives of so many in his career that was so sadly cut short.

The Proceedings of the conference have been published thanks to the generous financial and other support of the BAS Executive Council and of the Academic Publishing House “Prof. Marin Drinov”. Nearly all the papers presented during the Conference are included here, the only papers missing being those not submitted by authors for a variety of reasons. They have been internally refereed and slight changes made (e.g. to the English) here and there. A wide variety of topics are addressed, including the following:

• The eclipsed Sun’s Corona;
• Prominences;
• Terrestrial atmospheric Responses during the Eclipse;
• Biological and Other Effects during the Eclipse.

Each part of the Proceedings begins with the invited papers in the order of their presentation.

The editors are grateful to everyone who contributed to the preparation and publishing of the Proceedings of the International Conference "First Results of 1999 Total Eclipse Observations" and especially to Dr Vichko Tsanev for the huge amount of work involved in the preparation of manuscripts for the publisher. They believe that these Proceedings will be considered a significant step in our understanding of the solar atmosphere, the interaction of the Sun with the Earth, and the many and various effects total eclipses have on the Earth, its atmosphere and its lifeforms.

Dimitar Mishev
Kenneth J. H. Phillips

Sofia, September 2001