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(meteorobs) ZHRs



Hi group,

I would have gotten back to you all a little sooner, but I unexpectedly had
to double back from yesterday's day shift to the mid shift, and as all
meteor observers know, you have to sleep sooner or later.

Some interesting points are being brought up here.  Cathy Hall asks:

>< Who>  is most likely to cruise web pages?

Just about anyone, that's who.  You need to look at what's happening around
you to answer that question.  Something like 40% of homes have computers in
them  now, and more and more are hooking up to the internet.  My two
daughters have internet access at their school, Makalapa Elementary
(http://www.makalapa.k12.hi.us).  Walk into our public library, and there
sits the public access computer, with (usually) some 12-year-old sitting
enthralled in front of the web browser.  More and more people have internet
access, and they are using it to go wherever it takes them. 

This is why the AMS pages were moved to begin with.  Dr. Meisel was getting
bombarded with e-mail from all over, asking about Hale-Bopp, the objects
following Hale-Bopp, asteroids, the planets, UFOs, conspiracy theories, all
kinds of things having nothing to do with the basic AMS mission.  He wanted
to junk the AMS site entirely, until Jim Richardson and I convinced him that
we needed the web presence, and I volunteered to take the whole thing off
his back.  Jim and I will also handle all the e-mail that comes in, and we
are going to use the more sane questions to develop a FAQ that we can e-mail
off to anyone with general questions.  Just by providing links to better
sources of info on Hale-Bopp, etc., the traffic is all ready down, so we're
happy.  

The NAMN appears, by its nature, to have restricted itself to a
computer-owning, more or less internet-savvy subset of people.  Don't forget
to come up for air once in a while, though, and be aware of the
technological changes happening in society around you. Don't imagine that
the NAMN illuminati are the only ones who tread here. 

George Zay said:

>Quote the standard rate for it's peak hours

And just what is the "standard" rate?  Does being "professional" to you mean
parroting IMO documents?  This seems to be your drift.  

I found it interesting to go to several internet sources and look for rate
quotations for the major showers.  I also threw in some actual observed
rates for fun.  Since tables don't tend to hang together properly in e-mail,
I'll just quote a couple of examples of what I found.  Anyone that wants the
whole list, let me know, I'll send you a text file. 

Anyway, in here's some examples:

In some cases we agree:

Lyrids -- 

AMS = 15
Gary Kronk = 10
IMO = 15
DMS = N/A
Highest raw rate from NAMN 1996 records = 17

In some cases we disagree:

Eta Aquarids -- 

AMS = 20
Gary Kronk = 20
IMO = ZHR 60
DMS = ZHR 36.7 +/-5
Highest raw rate from NAMN 1996 records = 5

Here's what I found for the Perseids:

AMS=50
Gary Kronk=ZHR 80
IMO=ZHR 100
DMS=ZHR 84 +/-5
Highest raw rate from NAMN 1996 records=53 

I really like the way the Dutch show it, quoting the ZHR AND including the
statistical error limit, giving a good idea of the size of the sample used
to compute it.  The IMO is fond of quoting big ZHR numbers, and I worry a
little about the validity of some of it.  I noted on the IMO site one
observer's numbers from the Geminids, with a ZHR computed of 119... with an
error of plus or minus 45!  That would come from a sample size of 7 meteors
or less, and I wonder about such extreme extrapolation from a relatively
tiny sample.  Now don't get upset, this is not an attack on the IMO, just an
observation on one data point among many with lower errors. To illustrate
the danger of "extreme" ZHR calculation, I went through the calculations for
an observation I made in 1972.  A group of us here in Hawaii went out to
look for possible Giacobinids.  I saw what I believe was ONE Giacobinid.
Going through the calculations, the ONE meteor yields a ZHR of 29, with an
error limit of 29.  Statisticly valid?  You be the judge.

So what will we put in the AMS document when we re-write it?  Jim Richardson
has asked Norman McLeod to cook us up a set of numbers, probably two sets:
a set of ZHRs, and a set that will indicate what the average observer, under
average dark skies, can expect to see.

I would expect the ZHRs would be in the vicinity of the Kronk/DMS numbers.
They seem to agree pretty well, and with other print sources as well.  And
actually, with the exception of the couple of major showers George seized
upon, we agree pretty well.  The only "BS" involved is when scientists or
observers, amateur or otherwise, fail to keep an open mind.

Aloha,

Jim Bedient
Honolulu, Hawaii

P.S. Well taken point about Comet Kohoutek, Cathy.  I, too, still say it was
one of the nicest comets I've seen, and tell people that.

Here's my all-time favorite comet list, in order:

1. Bennett
2. West
3. Kohoutek
4. Hale-Bopp
5. Hyakutake

Bye!