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This page was last modified on December 5, 2001 by Marc de Lignie and Marco Langbroek and Casper ter Kuile, |
Leonids 2001: Expedition
The DMS-US Leonid Expedition 2001
by Marc de Lignie, Marco Langbroek, Rita Verhoef, Romke Schievink and Ralf Mulder
Impressions and observations by Bob Lunsford
I had the pleasure of viewing the Leonids with two groups this past week. I met up with the Dutch group stationed at Safford, Arizona on Thursday November 15. This group included Marco Langbroek, Marc DeLigne, Rita Verhoef, Romke Schievink, Ralf and Esther (whose last name I cannot recall). Sadly Carl Johannick was unable to make the trip due to injury:( We checked out the skies that night at the Safford Science Museum on the outskirts of town. The skies were dark enough to present the Gegenschein and the zodiacal band. Unfortunately there was interference from traffic and some annoying local lights. We decided to look for a better location.
On Friday we spent most of the day checking out possible observing sites. Our first destination was Mt. Graham and we found one good site on the lower eastern slopes. Some of the horizons were compromised so we headed in the opposite direction. We found an even better spot with great horizons in the Gila Mountains area northeast of Safford. We observed there Saturday morning and noted some impressive Taurid activity. The first meteor of the night was a slow green -6 Taurid that appeared near the northern horizon. The last meteor of the night was a -8 to -10 Leonid that lit the scene and left an impressive train.
After breakfast and a quick nap it was time to say good bye to my Dutch comrades. Actually all but Marco were still sleeping as I left for Mt. Lemmon. It would had been difficult to say good-bye in person as they were all so nice to me. It was a beautiful drive westward. The transition from desert to mountain scenery was spectacular. I did notice a bank of cirrus to the west that worried me somewhat. Once up on the mountain top it was good to renew acquaintances with Dave Holman, Tom Kucharski and Jim Richardson. It was also great to meet the energetic observers from Europe; Javor Krac, Jure Atanakov, Jure Zakrajsek, and Ana Mancic. As the afternoon progressed the skies became more and more of a concern. Satellite pictures showed variable cloudiness over most of the southern half of Arizona. The southeast area of the state showed the most promise. We decided to sit tight and try to get a nap.
We woke at 2000 (8pm) under dreadful skies. The Europeans were understandable nervous and were thinking seriously about relocating. The satellite picture showed that the worst was over us at the moment and that skies should get better. We just did not know how much better! My main concern was a large blob of clouds over Southern California that was heading our way. I figured it should arrive near dawn and that we would be safe until then, that is if it ever cleared up at all!.
The mostly cloudy skies prevented me from observing before local midnight. Shortly after midnight the Europeans began seeing some impressive earthgrazers and greeted them with shouts of joy. I started watching at 12:45 local time when there were large breaks in the cirrus. The clouds may have still been there but they were thin enough to allow unhampered viewing with a sight loss of limiting magnitude. Occasionally a denser patch of cirrus would float by but it was easy just to change my field of view to watch in better skies.
Rates and the brightness of the Leonids were impressive right from the start. The long Leonids continued for at least another hour. It was easy to record on tape and click the mouse early in the session. It became a little more difficult when activity really picked up around 10 UT (3am MST). I also began photographing the show at this point. My next check of my cassette recorder revealed that it had stopped recording in the 33F (1 C) temperature. After a loss of 3 minutes changing batteries it seemed to be working again. A bit later on it quit again so I employed by backup recorder which worked flawlessly the remainder of the night.
The rates climbed steadily and seemed to reach a peak around 10:45 UT (3:45am MST) with rates near 30 per minute. Rates slowed somewhat for the next 15 minutes but shortly after the hour activity picked up again. The show climaxed near 11:05 UT when 6 near simultaneous Leonids shot in different directions creating the "spokes of a wheel" effect. This effect can only be seen when the radiant lies within your field of view. Those looking toward the radiant had the advantage of seeing Leonids shooting in all directions and had no difficulty seeing the shorter/slower Leonids. Much to my surprise the rates still remained strong the remainder of the night and did not fall off rapidly as had occurred in 1999. For this reason plus the tremendous number of bright meteors, the 2001 Leonid shower surpassed the 1999 event, at least in my mind.
After 5:00am the cirrus became more of a nuisance as that blob of clouds from Southern California began to arrive. By the time I stopped recording at 5:45am it was getting difficult to find a cloud free section of the sky in which to watch.
I spent the next 30 minutes wrapped in a blanket just standing around marveling at the still impressive show occurring during the brightening twilight. I have to admit that after all the energy put forth in recording the activity it was certainly nice just to stand there and watch in relaxed mode. Just before stepping into the observatory dome I was rewarding with a -8 Leonid fireball producing 3 flares before being extinguished by clouds low in the northern sky. The sunrise was also impressive with its many vivid colors.
Before heading to bed we toasted the night with a magnum of champagne which was the perfect way to end a night such a fantastic night shared with special people. Marco was kind enough to phone me later that day saying they obtained similar rates under slightly better conditions from their eastern Arizona location.
Nov 18, 2001
15 MINUTE INTERVALS 0745-0800 UT 9 Leonids 1 SPO Estimated LM +5.4 0800-0815 UT 11 " 2 " " +4.7 0815-0830 UT 10 " 1 " " +5.0 0830-0845 UT 8 " 0 " " +5.5 0845-0900 UT 20 " 2 NTA " +5.7 0900-0915 UT 33 " 0 SPO " +5.8 0915-0930 UT 35 " 2 NTA/1 SPO " +5.9 5 MINUTE INTERVALS 0930-0935 UT 21 " 1 AMO/2 SPO " +5.9 0935-0940 UT 30 " 3 SPO " +6.0 0940-0945 UT 29 " 2 " " +6.0 0945-0950 UT 25 " 1 AMO/2 SPO " +6.0 0950-0955 UT 33 " 2 SPO " +6.0 0955-1000 UT 44 " 1 AMO/1 SPO " +6.0 1 MINUTE INTERVALS 1000-1001 UT 6 " 1 " " +6.0 1001-1002 UT 11 " 0 " " +6.0 1002-1003 UT 7 " 1 " " +6.0 1003-1004 UT 3 " 0 " " +6.0 1004-1005 UT 4 " 0 " " +6.1 1005-1006 UT 6 " 0 " " +6.1 1006-1007 UT BREAK " " 1007-1008 UT BREAK " " 1008-1009 UT BREAK " " 1009-1010 UT 13 " 0 " " +6.2 1010-1011 UT 5 " 0 " " +6.2 1011-1012 UT 13 " 0 " " +6.2 1012-1013 UT 11 " 0 " " +6.2 1013-1014 UT 4 " 1 " " +6.2 1014-1015 UT 11 " 1 " " +6.2 1015-1016 UT 11 " 1 " " +6.2 1016-1017 UT 16 " 0 " " +6.2 1017-1018 UT 19 " 0 " " +6.2 1018-1019 UT 15 " 0 " " +6.3 1019-1020 UT 10 " 1 " " +6.3 1020-1021 UT 15 " 0 " " +6.3 1021-1022 UT 12 " 1 " " +6.3 1022-1023 UT 9 " 0 " " +6.3 1023-1024 UT 17 " 0 " " +6.3 1024-1025 UT 16 " 0 " " +6.3 1025-1026 UT 14 " 1 " " +6.3 1026-1027 UT 11 " 0 " " +6.3 1027-1028 UT 14 " 0 " " +6.4 1028-1029 UT 21 " 0 " " +6.4 1029-1030 UT 21 " 1 " " +6.4 1030-1031 UT 17 " 0 " " +6.4 1031-1032 UT 12 " 0 " " +6.4 1032-1033 UT 12 " 0 " " +6.4 1033-1034 UT 21 " 0 " " +6.4 1034-1035 UT 13 " 0 " " +6.4 1035-1036 UT 14 " 0 " " +6.4 1036-1037 UT 16 " 0 " " +6.4 1037-1038 UT 24 " 0 " " +6.4 1038-1039 UT 26 " 0 " " +6.4 1039-1040 UT 18 " 1 " " +6.4 1040-1041 UT 20 " 1 " " +6.4 1041-1042 UT 18 " 1 NPX " +6.4 1042-1043 UT 21 " 0 SPO " +6.4 1043-1044 UT 17 " 0 " " +6.4 1044-1045 UT 28 " 0 " " +6.4 1045-1046 UT 28 " 0 " " +6.4 1046-1047 UT 26 " 0 " " +6.4 1047-1048 UT 22 " 0 " " +6.4 1048-1049 UT 17 " 0 " " +6.4 1049-1050 UT 19 " 0 " " +6.4 1050-1051 UT 15 " 0 " " +6.4 1051-1052 UT 21 " 0 " " +6.4 1052-1053 UT 13 " 0 " " +6.4 1053-1054 UT 13 " 1 " " +6.4 1054-1055 UT 19 " 2 " " +6.4 1055-1056 UT 9 " 0 " " +6.4 1056-1057 UT 18 " 0 " " +6.3 1057-1058 UT 18 " 3 " " +6.3 1058-1059 UT 24 " 0 " " +6.3 1059-1100 UT 22 " 0 " " +6.3 1100-1101 UT 21 " 0 " " +6.3 1101-1102 UT 27 " 0 " " +6.3 1102-1103 UT 22 " 0 " " +6.3 1103-1104 UT 20 " 0 " " +6.3 1104-1105 UT 16 " 0 " " +6.3 1105-1106 UT 35 " 0 " " +6.3 1106-1107 UT 23 " 0 " " +6.3 1107-1108 UT 16 " 1 " " +6.3 1108-1109 UT 25 " 1 " " +6.3 1109-1110 UT 11 " 0 " " +6.3 1110-1111 UT 12 " 0 " " +6.3 1111-1112 UT 19 " 0 " " +6.3 1112-1113 UT 14 " 0 " " +6.3 1113-1114 UT 11 " 0 " " +6.3 1114-1115 UT 13 " 0 " " +6.3 1115-1116 UT 18 " 0 " " +6.3 1116-1117 UT 12 " 0 " " +6.3 1117-1118 UT 12 " 0 " " +6.3 1118-1119 UT 14 " 0 " " +6.3 1119-1120 UT 11 " 0 " " +6.3 1120-1121 UT 10 " 1 " " +6.3 1121-1122 UT 9 " 0 " " +6.3 1122-1123 UT 15 " 0 " " +6.3 1123-1124 UT 15 " 0 " " +6.3 1124-1125 UT 5 " 1 " " +6.2 1125-1126 UT 2 " 1 " " +6.2 1126-1127 UT 15 " 0 " " +6.1 1127-1128 UT 13 " 0 " " +5.9 1129-1130 UT 10 " 0 " " +5.8 1130-1131 UT 11 " 0 " " +5.7 1131-1132 UT 7 " 0 " " +5.7 1132-1133 UT 10 " 0 " " +5.7 1133-1134 UT 4 " 0 " " +5.7 1134-1135 UT 7 " 0 " " +5.7 5 MINUTE INTERVALS 1135-1140 UT 37 " 0 " " +5.8 1140-1145 UT 28 " 2 " " +5.8 1145-1150 UT 23 " 2 " " +5.8 1150-1155 UT 22 " 1 " " +5.7 1155-1200 UT 21 " 0 " " +5.7 1200-1205 UT 20 " 1 " " +5.6 1205-1210 UT 28 " 0 " " +5.6 1210-1215 UT 17 " 2 " " +5.6 1215-1220 UT 19 " 1 " " +5.6 1220-1225 UT 20 " 1 " " +5.7 1225-1230 UT 19 " 1 " " +5.7 1230-1235 UT 29 " 2 " " +5.7 1235-1240 UT 17 " 1 " " +5.7 1240-1245 UT 29 " 0 " " +5.7 Totals: Leonids 1998 Spordics 53 North Taurids 4 Alpha Monocerotids 3 Northern Apex 1 Grand Totals: 2059 meteors in 4.95 hours (297 minutes), 6.93 meteors per minute or 1 meteor every 8.66 seconds. Bob Lunsford
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This page was last modified on December 5, 2001 by Marc de Lignie and Marco Langbroek and Casper ter Kuile, |