(meteorobs) Geminid comparisons

[Norman W. McLeod III]

Kim,

Lots to respond to.  Similar discussions have been done in the past.


>         Amazing that you and I could reach such completely opposite 
> conclusions.   From *my* single-person, and therefore unscientific, 
> viewpoint, the Geminids were mighty strong this year.

No doubt about that, when you are capable of seeing rates that 
high.  100/hr will blow almost anybody away.  But I have past years to 
compare with.  This is similar to Wes in Oregon being impressed with 
today's Perseids when I have had quite a decline after 1991.  Wes has 
almost three times my perception.


>My rates topped out at over 100 per hour yet I had a sky almost a full 
>magnitude lower than yours -- this despite the fact that we are both at 
>very similar longitudes.

Just imagine what you would have seen with me in 1979.  Having you in a 
better sky as well, we are talking 200/hr.  Something to drool over.  There 
was an inexperienced observer with me that night, Chuck McRae, who did see 
190/hr just counting.  A few other occasions got Chuck established quite 
firmly at double my perception.

Bill Gates never did get to see the Geminids from New Mexico, always 
clouded out in December.  We were just itching to find out what he could 
come up with -- I would think 250/hr easily.  For years Bill was doubting 
the rest of us a little on the vast superiority of the Geminids over the 
Perseids.  By 1977 he finally began to relent, but he disappeared in 1981.


>Dec 13.294  07:03   261.553     30    212    140  +- 10...........  with 
>140 being the ZHR.

The ZHR's have numerous individuals that see more than I do.  Hence the 
final result is fully twice what I personally see.  The general public sees 
about what I do.


>I'd never argue that the Geminids aren't on their decline, but from what 
>I've seen, you wouldn't be able to judge that by this year's return.

You have to have the earlier years to be able to tell.


>I did experience the bright post-max Geminids.

Glad to hear it's still there.  I didn't get to cover hours late enough, 
but in the past it had always kicked in early on Dec 13/14.


>   And, though this is a leap year, the maximum occured at roughly its 
> expected time, not a day early,

No problem here.  I specified that American longitudes only would have the 
highest rates a day early, not that the time of maximum itself had 
shifted.  My expectation was right on the money.


>It can't be my perception....I have yet to be convinced that I have 
>anything other than average perception -- One night's observing with Bob 
>and Lew assured me of that!  Please tell Joan I said hi!

But it is perception all the way.  (Bill Gates thought he was normal, 
observing from  "great mountain skies"   in New Mexico.  Once he joined us 
in the Keys in 1973, an  "inferior"  sea-level site, it took only 10 
minutes to find out that Gates had extraordinary perception.)  There have 
been quite a few other times when you report rates about 50% higher than I 
do, in sky LM a magnitude poorer.  If you get to observe in fully dark 
skies, you would easily be double my rates.

Bob and Lew have consistently had double my perception also, for their 
entire observing careers.   Bob has always been a U.S. Perseid champion 
along with Paul Jones.  Lew was with me starting at age 12.  He seemed 
similar to me at first in rates, but quickly about doubled me.

Two ZHR's need to be done -- one for the general population, and one for 
experienced meteor observers.  The second group will have ZHR's twice the 
first, going strictly by observation.  More high perceptions materialized 
after the 1960's as interest in meteor observing increased.  There was a 
time when I was seeing about the same rates as most other contemporary 
active observers.  After 1970 I gradually fell further and further behind 
as high perceptions were coming out of the woodwork.  There is a natural 
bias toward the high-perception side.  People that don't see many meteors 
will lost interest sooner and drop out.  The ability to see more meteors 
will get the blood moving and sustain interest for much longer.  I would 
not have held interest this long if I were at 80% of my perception level.

There are several indicators that I am normal with respect to the general 
population.  In the early 1980's Jeff Wood in Perth had a large group of 
school observers, 50 or more.  My perception landed right in the middle of 
this group.  In 1973 with 6 of us in the Keys, 2 of them were seeing about 
15-20% more than I, with 2 others about that amount less.  Right in the 
middle again.  Gates was the last one, almost 4 times our rates -- I am 
setting him aside for this comparison.  In my earliest days with a group of 
6 of us, I personally saw the most !  How misled I was over that, thinking 
I had very good eyes for meteors -- until someone else for the 1963 
Perseids in the Keys saw 50% more.  I couldn't understand how anyone could 
see more than I did, especially that much more, having never been beaten 
before.  Finally, the general long-term rates for some of the major showers 
are about the same as I became used to seeing, e.g. Orionids 25, Lyrids 15 
(before 1982), Eta Aquarids 10-15, Leonids (off-years) 15, sporadics 
overall average about 7, early hours 3-5, late hours 10-15.

Onward to the Quadrantids.  Good news for American zones on this one -- it 
is our turn for a good year.  Two cycles back, in 1997, I saw 61/hr Quads 
but with a thick crescent moon.  Of all the rotten luck, 2004 isn't 
moonless either.  Just glad it's past last quarter.

Norman




Norman W. McLeod III
Staff Advisor
American Meteor Society

Fort Myers, Florida
nmcleod at peganet.com