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(meteorobs) Leonid report - narrative - Nov 17/18, Mt. Lemmon, AZ (ATAJU)

Hi!

   Here's my written report for the peak night. As Bob's already mentioned, the 
skies were almost completely overcast with thin cirrus on the evening of the 
peak, around 8pm. Naturally, I almost panicked. As there was no clearing in 
sight, Jure, Javor and I (and later even Dave Holman) began thinking about 
relocating. Fortunately for us, Bob kept a cool head, predicting the weather to 
clear. So, we stayed.
   I started at 0720 UT with 40 irrus cover and a LM of 5.7. Almost 
immediately two long grazers appeared, a -1m and a -2m, both going over 90 
degrees. In the following 10 minutes 6 more grazers appeared, 4 of them being 
of negative magnitude! By 0800 UT cloud cover had decreased to 25% and LM 
dropped to 6.5. More Leonids appeared plus a couple of Taurids.
   By 0810 I was seeing roughly one Leonid per minute. At the time I also saw 
my first fireball of the night, an 80 degrees long -4m Leonid. Leonid rate 
slowly increased to 3-4 per minute around 0900 UT. By 0930 there were 6-8 per 
minute, with many bright Leonids. The cloud cover was variable, between 0 and 
20%. But even through the cirrus we could see many bright Leonids.
Around 1000 UT I hit 20 Leo/min. It was becoming quite difficult to record all 
Leonid magnitudes as accurately as I wanted to. 
   At that time I heard Jim inside the dome say we had reached ZHR 1200 or so, 
so it was officially storm level. The 'smart' mouse was really suffering from 
the constant onslaught of meteors by this time. Expecting the rates to drop 
after 10 UT I was pleasantly surprised to find them still going up. By 1015 UT 
there were 30/min. By now I'd quit estimating magnitudes. Unlike what Norman 
McLeod reported for a similar rate back in 1966, the Leonids were coming in 
groups with voids of a couple of seconds in between. Fireballs up to -6m were 
appearing in the order of up to 1 per minute. By 1030, the last predicted peak 
time (by dr. Jenniskens) there were 45/min. At 1045 UT a spike of 60 Leo/min 
followed by 54 Leo/min was observed. The spike was flanked by lower rates of 33 
and 37/min. The first Leonid showstopper was seen: a -8m blue fireball with 
train 12 minutes. The rates climbed to peak around 1105 UT with the top rate of 
64 Leo/min, with rates above 50/min for 8 minutes centered on that time. 
Another -8m Leo. Leonids were appearing everywhere, especially the last 20 
degrees above the horizon were seeing loads of Leonids.
   After that the rates dropped off quite rapidly. By 11:15 there were 35/min, 
25/min at 1125 and 15/min at 1135. More very bright fireballs. From 1130 to 
1200 there were roughly 10/min, but then a 10 minute subpeak appeared with 
rates of up to 18/min. The rates dropped off thereafter to 8/min. Cloud cover 
increased to 20-40%. By the beginning of morning twilight around 1255 UT there 
were still 4-6 Leo/min. A brilliant -8m sporadic behind a bank of cirrus 
finished the night. It was also observed on FISTA.

   Words fail to describe the amazing 6 hours on Mt. Lemmon. Apart from the 
team of observers, there were several casual observers who were just enjoying 
the show in the sky and the screaming six persons gasping for air while 
exictedly babbling Leonid magnitudes and numbers into their tape recorders. 
Thanks again to David Holman for making it all happen, Jim Richardson for 
excellent computer support and Bob Lunsford for keeping a cool head. Great 
stuff!

   In a total of 5.5hrs teff I'd seed an amazing total of 4110 Leonids, 11 
Taurids and 64 sporadics. No less than 186 Leonids were fireballs, with the 
following distribution: -8(4) -7(5) -6(11) -5(23) -4(57) -3(86). Also a -8m 
sporadic (flash) was seen through the bank of cirrus clouds in the northeast, 
later confirmed to be a fireball by FISTA. Well, can hardly wait for 2002!

Clear skies folx!

Jure A.

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