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(meteorobs) (Leonid) Questions :>
HiGH all!
There are some questions poking me in the head and I have to get them out,
so here it goes:
1. Maximum ZHR in a n-rev trail: in a paper by Asher (I think from IMC99), it
is stated that at least to a first approximation and for trails not too old,
the peak ZHR of the trail declines with 1/N, where N is the number of
revolutions. If the peak ZHR of a 1-rev trail at optimal da0 is about 300 000,
then a trail would be capable of producing ZHR > 1000 for 300 revolutions.
Okay, that may be a bit optimistic, so let's say it decreases with 1/N^2. Then
a trail would be capable of producing ZHR > 1000 for about 17 revolutions. Ok,
still with me? Good. Now, the center of the trail lags behind the comet and the
lag increases with time (number of revolutions).
THE QUESTION: The 7-rev trail was more than capable of producing storm level
activity this year. Could older trails produce storms even further away from
the comet than 4 years? Has anyone calculated this?
2. Also, I've seen dust trail predictions for past storms in 1833, 1866 and
1966. What trails caused the 1832, 1867, 1868, 1900 and 1901 storms?
3. Ok, one more (I've spent far too much time thinking about this...). Esko
hinted at the possibility of an Ursid outburst for this year - when the Ursid
parent comet is around aphelion. Ok, perhaps nothing will materialise, but
there was an outburst in 1985 when the comet was also around aphelion. Old
Ursid dust trails are capable of producing outbursts even halfway around the
orbit. Could something like this happen with the Leonids? (see the 1. question
again). Perhaps it happened but nobody saw it?
I hope this was not too much!
Clear skies!
Jure A.
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