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Re: (meteorobs) David Asher's Leonid calculations
In a message dated 99-04-16 03:53:39 EDT, rmn@aaocbn.aaodot gov.au writes:
<< Both David and I have looked at the consequences of his calculations in a
paper submitted to WGN. We would like to think that much of the uncertainty
in
predicting the Leonids has now disappeared, but that will be for others to
judge! >>
In the next few days I will be submitting my own paper/article to Sky &
Telescope and WGN concerning the 1999 Leonids. David Asher was kind enough
to look over my manuscript and gave it a nice review. Interestingly, for a
projected time of the peak of the Leonids, I used two techniques. One was
simple extrapolation of the past three years of the solar longitude of the
storm component. For 1999, this extrapolated value gives 235.38 degrees
which corresponds to 4:17 UT on November 18. Recall that we had a discussion
here a few months ago speculating on whether the east coast of North America
would be able to see a display of "Earth-skimmers" late on the evening of
the 17th (if the peak were to indeed occur around this time).
The other time is based on a forward integration of the 1966 ortho-swarm of
Leonids -- the meteoroids that gave rise to the stupendous Leonid storm of
that year. I found that in 1999, the same concentration of particles will
sweep to within 0.0026 AU of Earth, suggesting another potentially
spectacular display awaits us. More interestingly, the time of maximum that
I obtained based on this integration is 2:08 UT on November 18 -- which is
EXACTLY what David obtained in his meteor trail study!
I wish I had the same confidence about all these calculations that Rob has!
I remember how confident I was in 1993 after comet Swift-Tuttle passed on by;
I really honestly felt that we were in for Perseid storm . . . but we saw
nothing more than a moderately-strong display. As for the upcoming Leonids,
I'll only go as far as saying that they look like they'll be capable of
producing an "interesting" display. (The term "interesting" is left open to
wide interpretation!) :)
-- joe rao
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