Leonids 1998: Observational Results!

Sino-Dutch Leonid Expedition 1998

General Information on the Expedition

1. Pictures of the expedition
2. Basic visual data (grand totals)
3. First announcement
4. Official Press Release
5. Acknowledgements to our Sponsors
6. Preparations for the expedition

(Last updated: 98-12-31)

1. Pictures of the Expedition

The expedition has arrived at the Beijing Airport and is waiting for transport to the Beijing Astronomical Observatory (BAO).
We just met Mr. Jhu Zin who is arranging transport while this picture is made.

Hans Betlem and Casper ter Kuile inspected the expedition cargo when it was stocked by U-Freight outside the international airport Beijing.

The members of the Sino-Dutch Leonid Expedition 1998 pose in front of the entrance of the Beijing Astronomical Observatory (BAO) at the beginning of the expedition.
From left to right are: Peter Bus, Pavel Spurny, Carl Johannink, Annemarie Zoete, Romke Schievink, Robert Haas, Marc de Lignie, Michelle van Rossum, Alex Scholten, Klaas Jobse, Jaap van 't Leven, Olga van Mil, Arnold Tukkers, Jos Nijland and Hans Betlem.

During our two-day site-seeing we visited the well known "Forbidden City".
Seen from left to right on the back are Koen Miskotte, Carl Johannink and Marc de Lignie.

The expeditionmembers pose in the forbidden city during their site-seeing trip in Beijing at the beginning of the expedition.
From left to right are: Olga van Mil, Klaas Jobse, Arnold Tukkers, Carl Johannink, Alex Scholten, Michelle van Rossum, Annemarie Zoete, Marco Langbroek, Jos Nijland, Peter Bus and Romke Schievink.

Lunch at a local restaurant between our visits to the Forbidden City and the Lama Temple.
Counterclockwise around the table are: Peter Bus (seen at back), Romke Schievink, Arnold Tukkers, Marco Langbroek, Carl Johannink, Alex Scholten, Annemarie Zoete, Pavel Spurny and Klaas Jobse.

The Lama Temple.

Carl Johannink in front of the Temple of Heaven.

A stop at one of the gift shops.

Carl Johannink (left) and Marc de Lignie (right) walking on the famous great wall during our two-day site-seeing tour in and around Beijing.

Casper ter Kuile (Left) and Carl Johannink (right) pose on the Great Wall.

Marco Langbroek (left) and Pavel Spurny (right) walking on the Great Wall.

Lunch at a local restaurant after our visit to the Great Wall and before our visit to the Ming Tomben.

At the end of our two day site-seeing tour we were invited by our Chinese counterpart for diner at the Beijing Duck restaurant.
This picture shows expedition members using the well known Chinese "sticks".

The members of the Sino-Dutch Leonid Expedition 1998 pose in front of the Beijing Astronomical Observatory (BAO) just before the expedition leaves China when Beijing is covered by snow.
From left to right are: Hans Betlem, Michelle van Rossum, Annemarie Zoete, Olga van Mil, Marco Langbroek, Malcolm Currie, Renee Veldwijk, Paul van der Veen, Jos Nijland, Peter Bus, Romke Schievink, Jaap van 't Leven and Marc de Lignie.

2. Basic visual data (grand totals)

3. First announcement

On sunday November 22 the Sino-Dutch Leonid Expedition 1998 returned from China from her mission to observer the Leonid meteor stream. In a few words: a great success!!
Let us point out what happened.

We left you behind on saturday November 7 when we left off with Royal Dutch Airline (KLM) to Beijing. After arrival we first had two days site-seeing with the whole expedition (teams Delingha and Xinglong).

On wednesday November 11 both teams travelled to their respective destinations Delingha and Xinglong. After making arrangements with our local counterpart and installing our equipment the real work could start. This was carried out in three consequtive nights 16/17, 17/18 and 18/19 November.

The first night showed us many fireballs while the second did not show the forcasted outburst but only a little increase of activity. The first night however proved definity the best one of the three. More results can be found in the visual sections of both teams.

On all nights both stations from team Delingha were equiped with a 50 mm and a 85 mm camerabattery and an image intensifier system. One station (Ulan) was also equiped with a large field videosystem which gathered timings of possible photographed meteors. Results of the photographic- and video-projects can be found in their respective sections.

At this moment we cannot estimate the scope of the success of the expedition. There are still things which need improvement. But technically things have worked almost flawlessly and that is a very big success despity the extreme cold!

Casper ter Kuile
Sino-Dutch Leonid Expedition 1998
(Dutch Meteor Society)

4. Official Press Release

- Leonids did show up according to predictions.
- Sino-Dutch Leonid Expedition big succes.

The main part of the Leonid meteorstream did behave as predicted in the night of November 17/18. This conclusion is drawn by the Sino-Dutch Leonid Expedition of the Dutch Meteor Society from eight night of observations from two different locations in China.
Articles in the Dutch Press which state the Leonids would have appeared to early are based on interpretation errors of observations made solely from the Netherlands.
Nevertheless the expected outburst did not materilize, the maximum activity of the Leonids over Asia peaked at about 200 meteors per hour. Does number still is a remarkable number for interested researchers. The mediashow was a bit disappointing though but the big public gathered around the Chinese observatories was full of interest in the show.

As a surprise the expedition was sitting on first rows while a steady stream of bright fireballs passed by. This show lasted long enough so every observer around the world would benefit from it with highest rates above western Europe. Parts of the Netherlands were clear and observers in these area's were happy to enjoy the big show.

Also during the night of November 17/18 which also partly clear in the Netherlands the Sino-Dutch Leonid Expedition experienced big successes. While China is 7 hours ahead in time on the Netherlands the Leonids could be observed at the moment the earth crossed the orbit of comet Temple-Tuttle. Around 4 hours local time in China, about one hour after crossing the comits orbit, researchers observed an slightly increased activity.
The main part of the Leonid meteor stream appeared almost exactly at the time scientists computed. Only the activity was a bit disappointing and behaved like the more pessimistic computermodels.

The characteristics of the Leonid meteor stream in 1998 are comparable to that of the year 1965. That year too, about 14 hours before earth passed the comits orbit a steady stream of fireballs appeared and the outburstpeak was quite modest when compared to the next year 1966.

The Sino-Dutch Leonid Expedition 1998 which was setup specially to obtain information on the Leonid meteor stream between November 7 and 22 in China, is highly succesfull thanks to the very extensive observation programme.

Expeditionmembers were able to observe at 8 consequitive nights at 4 different locations in China so they could monitor the meteor stream over a longer time. Not only visual observations wre carried out but also 5 image intensifiers and about 80 photocamera's were put into service and recorded everything which appeared at the sky during this period.

The Sino-Dutch Leonid Expedition 1998 is sponsored by:


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back.gif This page was last modified on December 31, 1998 by
Casper ter Kuile, Marco Langbroek and Hans Betlem