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Re: (meteorobs) Re: 1997 Perseid max data NM
Norman wrote>
> Marco and I are just about identical for meteors down to +2m. Going
> fainter, he demolishes me with faint rates 3 and 4 times greater. I haven't
> seen anything like this since the days of Bill Gates, who was also very
> bottom-heavy in magnitude totals. Most high perceptions have been
> top-heavy, with faint rates only equal to mine and sometimes less. A good
> example of the latter is Bob Lunsford.
I used to have the same skewness. In group watches, I'd generally
have 3-4x more meteors than anyone else. More than 20 sporadics per
hour was normal. These were mostly 3 to 5 magnitude. It's hard to
achieve in the UK any more given the encroachment of light pollution
in the last 20 years. Regular +6.8/9 skies are long gone even in
rural areas in England. Glad to hear Marco, Casper and friends
seem to be experiencing the skies I had from 1968-76 on the other side
of the North Sea. In the last decade or so, we don't seem to get the
decent clear nights during the summer. If it's sunny, it soon becomes
hazy and humid. You're lucky to get a couple of consecutive decent
nights. In the 1970s we used to get runs of weeks of good nights.
This Perseid campaign has suffered like some many in recent years.
Let me do a Lew! How much are such differences due to different
limiting magnitudes (mine were generally 0.3-0.7 fainter than my
fellow observers), perception, and observing technique? For a given
observer, isn't the perception a function of magnitude? An example,
might make it clearer: could you have an observer seeing say 20% more
than the average at mag +2, but 3 times the norm (pun unintended) at
+4.
> Perception for showers vs. sporadics also differs. Bill Gates generally saw
> only twice my shower rates but ten times my sporadic rates, with overall
> perception 3.8. 50-70/hr just sporadics was typical for Gates -- one hour
> he exploded with a 104 ! That hour I saw 12 sporadics; there wasn't much
> else for me to do that hour but count what Gates was seeing. He ripped off
> a string of 21 meteors in one 5-minute period in which I saw nothing at all.
> We spent a lot of time studying him as well as his observing results. In
> the current period, Wes has 3-4X my sporadic rates while Marco has 4-5X.
I had a long argument with Robert Mackenzie about this around 1972. I
couldn't get him to allow for different population indices and lms
>+6.5, let alone my perception. There was a `normalize shower rates
to the sporadics' data reduction in vogue at the the time, which I knew
was wrong.
Malcolm
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