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Re: Eyes vs. telescopes (was Re: (meteorobs) Meteor observing food)
>... and I thought you were looking for telescopic meteors with
>your Astroscan, Lew!
As Malcolm points out in his own inimitable fashion, there *IS*
one good reason to bring a (small) telescope along for a meteor
observing session - telescopic meteor plotting!
This is very similar to visual meteor plotting: each meteor is
drawn on a star chart (IMO-issued) appropriate for the purpose.
In addition, magnitude and time are recorded for the meteor on
a separate sheet. The difference? IMO's Telescopic Charts are
of a MUCH smaller scall (1-3 degrees?), and provide stars down
to MUCH deeper magnitudes (9 to 12?) - making them appropriate
to plot meteors using binoculars or a 2"-5" WIDE-FIELD scope.
Because the areas of sky they cover are so much smaller, these
charts are also FAR more numerous - Malcolm issues 160 of them,
with 3 versions of each chart to cover a range of instruments.
IMO's Visual Plotting charts, by contrast, number only 12...
Advantages of telescopic meteor plotting are at least three:
One is GREATLY improved plotting accuracy - using telescopic
plots, radiant structures well below a degree are resolvable.
Second, it permits analysis over time of meteor shower rates
at much fainter magnitudes - there are showers so inherently
faint, they can ONLY be observed this way or with expensive,
cumbersome and difficult-to-use video equipment. Finally the
chance of plotting bias is reduced, due to the narrow field.
The difficulties of course include lower rates (1-5 per hour
versus 5-50 per hour with visual observing), more complexity
(telescope versus lawnchair), and comfort (an unbroken half-
hour at the eyepiece demands real attention to your comfort!)
Clear skies all,
Lew Gramer
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