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(meteorobs) Re: Revised AMS Meteor & Meteor Showers FAQ



Ed,

In regard to your question,

> 8. Does the published meteor rate for a shower really 
> represent what I should expect to see?

about the rates in the general AMS table, I am the one that put it together
based on what I have seen over the years since 1960.  It does indeed
represent what I was actually seeing, and I have seen every major shower
under a variety of conditions.  I see what the average person should see
rather than someone with high perception.  Observing with a number of people
over long periods of time indicates that the majority are quite similar to
me, within 30% of my rates either way.

Your effort in this, 

>I was trying to "correlate" or match up the ratios here of 
>column (1), full Moon, divided by column (3), moonless rural 
>sky (which vary from .20 to .40) with a statement on the IMO 
>Web site: "the full Moon reduces the observed number of 
>meteors by a factor of about 10!"

illustrates the difference in my observing experience vs. the IMO theory on
how much brighter skies reduce meteor rates.  I find the reduction to be
only half what the mathematically derived theory is predicting.  It is
possible, however, that high-perception observers are more adversely
affected by poorer skies than I am.

>... the variance of the ratios of (1)/(3) in the table 
>above may take into account the intrinsic brightness of the
>showers -- some brighter than others.

That looks very plausible to me.

>I'd also be interested in the values that would appear in 
>another column that combines BOTH city sky AND full Moon!  
>(My guess would be to multiply (1) by the ratio of (1)/(3) 
>-- resulting in a very dismal number indeed.)

I don't think it would drop off quite that much, and we're talking about a
lot of scatter within already low numbers.  The Eta Aquarids are more
strongly affected by latitude than any of the others, further south being
better until you get to about 10 degrees south of the equator -- above 40
degrees north you won't see many at all.


On another topic, Chuck's observation,

>During the East Coast U.S. early  evening on Nov 17, I noticed, numerous
>extremely dim, very rapid streams of light streaking across the sky.

so early at night causes me to think about a non-meteor source for this.
Right after dusk is the slowest time of night for meteors almost all year.
With no one else reporting this, what could be happening locally to cause
it?  Birds, insects, and flying seeds are capable of night streaks, as well
as glints of car headlights along power lines.  One family from the urban
Florida Gold Coast reported seeing numerous  "meteors"  moving N to S, with
a full moon in the sky, on the Draconid max night (evening of Oct 9)  in
1975 -- and this went on for a couple of hours.  With no other reports,
especially over that length of time, I again have to look for a local cause.

Norman

Norman W. McLeod III
Staff Advisor
American Meteor Society

Fort Myers, Florida
nmcleod@peganet.com

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