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Re: (meteorobs) A-T 1996 ZAYGE ...long article
George,
What bothers me about your "analysis" and last e-mail? Let me count the
ways.
1. Your previously defined attitude about the A-T's:
On 1995 August 19, Kevin asked you a simple question about the A-T's and
you responded on 1995 August 20 with, "No real radiant...probably best to
not favor any possible radiant at this stage." Considering that on the
latter date you also wrote to Marco Langbroek and wrote, "I really don't
know too much about this possible radiant," it would seem you were not in
a position to judge the radiant that way. Considering that extensive
articles were written about this stream and published in WGN and Meteor
News, you need to do a little more reading on a subject before
considering yourself qualified enough to make such a judgement call.
2. Your "Scientific" Method:
I am writing this at work and your response to me last night is currently
at home, but I believe you mentioned something along the lines of maybe I
was wishing too hard for the A-T's to be real and something about my
scientific methods for studying this stream are not based on observations
by experienced observers.
Okay, here we go (deep breath taken here, considering much of what
follows was withheld yesterday because I did not want to cause problems).
First of all, I have put as much into the A-T's as I have every other
minor shower I have investigated over the past 15 or so years. The same
data gathering methods were used. The same computer programs (which I
wrote mind you and have tested thoroughly) were used for orbital
computations. Considering I am working feverishly to finish volume one of
Cometography for my deadline next April, I do not a lot of time to dwell
extensively on meteor streams. I just pause by writing, investigate the
stream to death to determine it validity, and let people know about it. I
am sorry if my having accidentally found this stream poses a problem for
you.
Second, the observers who have seen this activity are experienced. I have
over 20 years of meteor observing experience. George Gliba has also been
around a long time. The current record holder (albeit posthumously) is
Cuno Hoffmeister, whose plots over a period of about 30 years revealed
several thousand radiants. He detected the A-T's in six different years,
including 1934, when it was also seen the same night by an observer in
the United States. Hoffmeister's radiants were all listed in his 1948
book Meteorstrome. The list of AMS observers who plotted A-T radiants
include several of that organization's most active observers of all time:
Franklin W. Smith (1934, 1940), Charles E. Worley (1950, 1951), and
Jeremy H. Knowles (1951, 1955). There were also many others.
Now for your method of analysis.
It is not very scientific to conduct what appears to have been intended
to be a definitive analysis by using the observations of only one
person--in this case, you. As I continue to analyze the Xi Draconid
stream found by Bob Lunsford, yourself, and several European observers in
June, I find that where three of the radiants are very close to each
other, two are not and one of those is yours. You and Bob Lunsford
observed the same night, at the same location, and saw essentially the
same meteors, yet your radiant does not fit in well with the majority of
the observers. With this in mind, how can I, or anybody for that matter,
trust your analysis of the A-T's based solely on your observations? Your
observations are great for the Xi Draconids, when combined with everyone
else's, but I would not do an analysis of that stream based solely on
your observations. It would prove nothing, especially in lieu of the fact
that the historical data favors the radiants determined by Lunsford,
Langbroek, and Haver. Here are the radiants and the parabolic orbits I
computed for them. As you can see, your radiant causes an inclination
decrease, which is an important factor in stream analysis.
Date RA DEC w W i q e Desig
274 +54 197.8 81.6 49.1 0.991 1.0 Zay
280 +53 199.1 81.6 53.2 0.987 1.0 Lunsford
1996/06/15 280 +55 196.3 84.5 52.2 0.995 1.0 Langbroek
284 +54 198.3 87.9 54.2 0.990 1.0 Haver
283 +58 191.9 88.0 52.8 1.005 1.0 Gorelli
Another point you always seem to focus on is the apparent velocity. This
once again was a major focal point in your little analysis of the A-T's.
If I remember correctly, your velocity estimates for the Xi Draconids
were exorbitant and contradicted those of every other observer. In fact,
they indicated not only hyperbolic movement, but excessive hyperbolic
movement. Despite the statements of others, including myself, you were
not willing to admit you might have made a mistake. This is bad science.
Even in the face of something quite impossible, you stood your ground,
and this lack of a willingness to give-in causes your data to have to be
used, which subsequently pollutes the final results. Once again, the
radio meteor data indicated that the Xi Draconids not only existed, but
that they moved at speeds decidedly slower that what you "observed".
Since your analysis of the A-T's began with eliminations based on only
YOUR estimates of the apparent velocity, I question the validity of your
analysis.
To conclude, as far as I can tell from what I read, you took YOUR plots,
which are of questionable precision (based on what I found with the Xi
Draconid data), you took YOUR apparent velocities, which are of
questionable precision (based on what I found with the Xi Draconid data),
and you basically....eye-balled it? Is this correct? You said nothing
about measuring the beginnings and ends of the plotted trails, and you
did not mention any mathematical method used for the analysis. Is this
your definition of the scientific method?
Gary W. Kronk