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Re: (meteorobs) Another failed Observing Session
Kevin,
Generally showers have been removed from some observing lists due to
lack of reliable evidence, or those that no longer exist. Showers with
ZHR's lower than say two an hour, which show no definate peak, cannot
really be reliably counted visually, due to sporadic pollution, and
unreliable shower association. Even plotting has large errors at this rate.
However, if huge numbers of plots are combined, you MAY be able to tease
them out of the noise.
Note that this does not mean that they are not worthy of plotting, and
are particularly well suited for photographic and video observations, where
much higher accuracy and velocity measurements can be made....but of course
at low rates it's not a very inviting target...'specially for photography
where the magnitude must be at least +1 or 0. Think how many of the alleged
2 an hour are going to be be that bright... remembering the magic "r" which
says there will be ~ 3 times less meteors at each step up in one magnitude.
So if it's 2 an hour ZHR, radiant is not at the zenith, LM is not at least
+6.5 there would be theoretically 1 or two a night...but 99.9 percent will
be too dim to photograph...so it's like 1 per 1000 hours..all of which has
to occur during the active period.
I think this will be one area where video observations can really
clear things up in the future, since meteors can be detected to +6 or
dimmer.
Other reported showers were based on a single occurence in one year of
the past, and have failed to be confirmed since.
Again, let me empasize that while they are not suitable visual
(counting)targets, that does not necessarily mean they do not exist.
I'll show you the article when the IMO trimmed their visual shower
list down. There, Rainer explains the rational behind each of the
decisions.
It is worth plotting these though, so....see you tonight?
Wayne