(meteorobs) NM first hourly Geminid rates with more

[Norman W. McLeod III]

I got my hourly Geminid rates done at this point.  Will be doing the 
five-minute bins and magnitudes next.

2004 Dec 12/13, 1026 - 426 EST ; 2004 Dec 13 UT, 326 - 926 UT
6 hours of Geminids : 49,45,53,72,54,48 -- sky LM 7.3 throughout.
sporadics : 5,5,1,3,7,10
minor showers : 3,3,1,6,2,2

2004 Dec 13/14, 826 - 1226 EST ; 2004 Dec 14 UT, 126 - 526 UT
4 hours of Geminids : 19,34,33,52 -- sky LM 7.3 throughout.
sporadics : 6,0,3,5
minor showers : 0,0,0,2

Looking at past leap years, including 2004 for comparison, with the same 
hours under similar conditions :

1972 Dec 12/13 : 24,46,57,54,73,61
1980 Dec 12/13 : 49,82,75,75,--,--
1996 Dec 12/13 : --,79,79,85,96,42
2004 Dec 12/13 : 49,45,53,72,54,48

1972 Dec 13/14 : --,--,--,36
1980 Dec 13/14 : --,--,35,54
1988 Dec 13/14 : 19,32,49,57
1992 Dec 13/14 : 17,--,--,--
1996 Dec 13/14 : --,--,--,44
2004 Dec 13/14 : 19,34,33,52


Dec 12/13 these tables cover the local hours 10 p.m. to 4 a.m.  Actual 
start times were within a minute of the 26th minute past the hour, 
according to what longitude I was at : central and southwest Florida.  Dec 
13/14 uses the local hours 8 p.m. to midnight.

It looks like 2004 was somewhat similar to 1972 in rates.  Back then the 
Geminid rates were increasing markedly, and I had a new hourly record that 
year.  As the 1970's progressed I set new records, topping out at 103/hr in 
1979.  That was my only occasion at over 100.  The 1980's and 1990's 
continued at very high levels with a few rates over 90.  Now that appears 
to be over with, as I have declined back to the 1972 level.  If there is to 
be a decrease in my rates due to age (now 58), I completely fail to see it 
happening yet.  These numbers look remarkably similar over a 32-year 
period.  The sky also looks as good as ever.

The Geminids were only noticed around 1850, and they will be shifting 
completely away from us in less than two centuries.  Somebody out there can 
fill us in with some serious information about the brief appearance of the 
Geminid shower.  I am glad to have been around for the best years.  It was 
just amazing to break 100/hour that one night.  I had hoped for further 
strengthening to sustained 100/hour rates, but no such luck.

For the first time I didn't get the changeover to bright Geminids on Dec 
13/14, at least up to 1230 a.m. when we stopped due to increasing 
fog.  Clouds came in soon after we returned home from a strong cold front 
arriving.  I had a brief string of bright Geminids causing me to think the 
change had just come, but then fainter Geminids resumed at fairly good rates.

Joan counted 49 unclassed meteors in about 3 hours of watching on Dec 
13/14.  She really enjoyed the show despite having to do it with only one 
good eye here on.

More later.


Norman


Norman W. McLeod III
Staff Advisor
American Meteor Society

Fort Myers, Florida
nmcleod at peganet.com