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Re: (meteorobs) Linearids observed!
Wayne T Hally wrote:
> The below is one reason that when I am plotting meteors, I make an effort
> to not know where the radiants are located on the night (or most times,
> morning) in question. This has led to a number of Perseid like meteors
> being rejected as Perseids since they were on the wrong side of,
> ironically, Cassiopeia. By not knowing the radiant location, at least my
> plot (of unknown accuracy) is not influenced by previous knowledge of the
> position.
>
> Wayne
>
> One more thing: Assume that say 20 fairly experienced meteor observers were
> "brain washed" to believe that the Perseid radiant was in the middle of
> Cassiopeia, and that these people were asked to plot meteors during the
> perseids. My guess is that they would generally plot mostly Cassiopeids for
> a
> long while provided the center of their field of view was sufficiently far
> away
> from the real radiant (several meteors between the real radiant and the
> wrong
> one would of course tell them that something was wrong). I'll bet they
> would be
> inclined to twist the trajectory a bit to fit with the expected radiant. I
> doubt
> they would even suspect that they did this for a long time. I am not saying
> that
> this is the case for your Linearid, but you should be pretty sure about the
> trajectory to rule out this possibility.
>
> Birger Andresen
>
My FOV was centered near Polaris, so the Linearid appeared just to the
upper left of center, so I could trace the trajectory back to the bowl
of the big dipper with high confidence.
I also observed 5 Taurid and 4 sporadic, in 2.5 hours. My error in
estimate of the Linearid trajectory was about 5 deg at the dipper (low
in N horizon) and 3 deg at the origin of the track (at elevation 40
deg). This is an area of sky about 160 deg^2, where the radiant could
possibly be located. The total sky is about 20,000 deg^2, so the
probability that 5 sporadic did not come from this area is roughly
(1-160/20,000)^5 = 96.0%, and you would need to see 87 sporadics, before
your odds were better than even to catch one with radiant in this area.
So, with my observation odds of only about 4% of catching a sporadic in
this spot, and given the fact we were near a nodal crossing of
J3/Linear, this is very likely to be a valid Linearid observation.
Also, there were 2 other observers who reported a total of 9 Linearids
between 10Nov 2323Z - 11Nov 0424Z, with no activity before and after
this time span. My single Linearid occured at 11Nov 0345Z, and none were
seen after that time up to 0715Z, when I ceased observation.
This corroborates my observation and indicates a small burst of activity
around this time.
M. Linnolt
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