Leonids 1995: The first DMS Leonid expedition

Leonid filament & dust trail encounters in 1995

Leonid-filament:

Dust trails: not expected and not observed


Picture 1: Logo Leonid expedition 1995 designed by Robert Haas

Introduction
After the first Leonid outburst in 1994 many outbursts of the Leonids were expected in the coming years, culminating in meteor storms in 1998 and 1999. The Dutch Meteor Society organized their first Leonid expedition to Andalusia, Spain in 1995. The aim for the DMS observers was to observe Leonids simultaneously with cameras as well as with video systems. Also visual observations were conducted. Here you will find my impression of this large expedition. In the week before the expedition all equipment and other material was collected by Hans Betlem and then transported to Spain with a a small truck. This is cheaper than sending it with an airplane. We also had a lot of sponsorship from Canon, Shell, Honda, Kodak and some scientific funds such as the Leidse Kerkhoven-Bosscha fund. The 22 (!) observers in total! ) flew with a plane to Malaga, Spain and all equipment would be on site before arriving.
This years conditions: during the second part of the night there was some light of a 35% illuminated moon.

Taurids & Alpha Monocerotids
This year is also a so called Asher year, a year the earth would encounter bigger particles of the Taurid meteoroid stream. this result in somewhat higher hourly counts and much brighter meteors and fireballs. Indeed I did see a couple of brighter Taurids: a stunning -8 and a -4. On the suggestion of Marco Langbroek and Peter Jenniskens the Leonid Expedition 1995 was extended until 23 November. During the night of 21 to 22 November 1995 Peter Jenniskens expected a brief outburst of alpha Monocerotids around 2:00 UT. This timing was ideal for Europe and since we are already in a good location the decision was easy for us to stay a couple of days longer in Andalusia. But there were many astronomers and amateurs who doubted Peter 's prediction ... Read the outcome of this prediction here. This alpha Monocerotid meteor shower had brief outbursts in 1935 , 1945 and 1985 with ZHR's between 500-1000.


Picture 2: Groupphoto of DMS Leonid 1995 expedition, in front of Public Observatory Bussloo.
Photo credits: Kees Roos.

14 November 1995
Our flight from Amsterdam Airport to Malaga, Spain. It was a large group of meteorobservers, 22 in total. After arrival at Malaga Airport, the team split up: Hans Betlem and some schoolkids rented a house near Almedinilla. Jaap van 't Leven, Klaas Jobse, Michiel van Vliet and Marc de Lignie occupied a house (hmm, it was more like a stable…) in the vicinity of Zafaraya. The team I was part of consisted of Casper ter Kuile, Marco Langbroek, Jos Nijland, Robert Haas and me. We drove to the small city of Alcudia de Guadix. We arrived at our home a bit after local midnight. We had some trouble finding the right house, but with some help of a (German) neighbor we did find it. It was a so-called cave-house and it's situated just outside of Alcudia. It was built in a hill that consists of debris from the Sierra Nevada Mountains. The sky was clear at that time, but we were tired of the journey so everyone go to sleep.


Picture 3: Dining room with a small kitchen. Photo credits: Casper ter Kuile.

15 November 1995
At daylight we had our first look at the surroundings of our home. Wow it was beautiful. The landscape looks a bit like the Grand Canyon and we had a good vieuw on the Sierra Nevada mountains. Robert and Casper went to meet a group of Spanish meteor observers to hand over some photographic equipment. At the village of Chirivel, they would be observing the Leonids as well. Jos, Marco and myself did some shopping in the village of Alcudia at a supermarket. That evening we had extremely variable weather. Within minutes the sky could clear up, and after some minutes clouds came in and vise versa. And on top of that above our heads was a big Lenticularis cloud which shieldeld a large part of the sky. Every now and then we walked outside to inspect the sky. During one inspection I did see a sporadic –5 fireball through the clouds, however. The path of the fireball was parallel to the ridge of the mountains in southeastern direction.

16/17 November 1995
After a cloudy day, we had some very clear spells. But they never lasted longer than 10 minutes when clouds came in again. We would check the weather until 3:00 UT, after that we went to sleep.

17/18 November 1995
When we woke up that morning the sky was blue with some small cumulus clouds. A phonecall to Carl Johannink at Gronau learned us that a coldfront was approching. Hopefully it would passing fast and clearings were on time before the radiant of the Leonids rises above the horizon. At noon the sky got cloudy and windy: the cold front is coming! We were hoping the coldfront would passed somewhere before 22:00 UT. And it did, around 21:00 the sky cleared partially and after some time most clouds disappeared.


Picture 4: The Big Taurid Fireball of 17 november 1995 as seen from Alcudia de Guadix. Photo credits: Casper ter Kuile.

Ok, action! Camera's and video systems outside! Jos and Marco climbed the hill behind the house to observe the Leonids further away from our house. When I aimed the video system at the sky, a bright and blue magnitude –8 or maybe -10 Taurid fireball appeared. It turned out that this fireball left a sonic boom, heart (and captured with the video systems) from Almedinilla and Zaffaraya. The limiting magnitude was 6.6 when the observations started, but when the moon rose in the east the limiting magnitude decreased to 6.2.
Just after starting observations (at the moment when the radiant of the Leonids rose above the eastern horizon) immediately the first Leonids became visible! Within half an hour some bright ones were seen: a –3 climbed from the horizon upwards into the constellation of Ursa Major and left a persistent train of 10 seconds. Another one of –3 lit up, parallel with the northwestern horizon. Yes, this is a Leonid outburst with many bright meteors up to –3. Big fireballs were not seen. Hourly counts reached 20 to 30 Leonids an hour. Zenital Hourly Rate: 35, which is three times higher than usual. We stopped with the observations at 6:00 UT. We were very satisfied because we did see the second Leonid outburst in the new series! The bright Leonids we observed this night were belonging to the "filament" structure of comet 55/P Tempel-Tuttle.


Picture 5: one of the many magnitude -3 Leonids seen during the night 17/18 november 1995. Photo credits: Casper ter Kuile.

18/19 November 1995
In the evening and the last two hours we had a clear sky. The Leonid activity is returned to normal values. The following nights I could observe more Leonids and other meteors.


Picture 6: Groupphoto of the Alcudia team: fltr: Casper, Koen, Marco, Jos and Robert.
Photocredits: Robert Haas.

19/20 November 1995
Clear night with good Taurid and Leonid activity.

19/20 November 1995
A short period of clear weather. After observations Jos and I talked a bit about the upcoming Alpha Monocerotid ountburst with Peter Jenniskens and Marco Langbroek.

21/22 November 1995
The last night was the clearest night ever since the start of my observations in 1980: limiting magnitude 7.0 during the last hours that night. Unfortunately during the famous Alpha Monocerotid outburst there was a thin blanket of cirrus, reducing lm to <6.0….

23 November 1995
Flight back to Amsterdam. It was a very inspiring expedition: two meteor outburst in one week! Let's go to the Leonids 1996!

Articles on the Leonids 1995
[1] Marco Langbroek: Een meteoren expeditie naar Andalusië, Zenit maart 1996, page 134-139
[2] Precisely reduced meteoroid trajectories and orbits from the 1995 Leonid meteor outburst, Hans Betlem, Casper ter Kuile, Jaap van’t Leven, Marc de Lignie, Luis Ramon Bellot, Mike Koop, Chris Angelo, Mike Wilson and Peter Jenniskens.

AstroRockers Blog

Leonid observations of Koen Miskotte

Meteorshowers

Introduction
Quadrantids
Lyrids
eta Aquariids
Southern Delta Aquariids
Capricornids
Perseïds
kappa Cygnids
Draconids
Orionids
Taurids N + S
Leonids
Geminids
Ursids

Year results


Leonids

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