[Prev][Next][Index][Thread]

(meteorobs) Telescopic charts for 5" refr 18x 3.5d (was Call for Observations - Kappa Leonids)

In answer to Lew's questions:
> >Have you any other 30-35mm f.l. eyepieces, Lew?
> 
> The nearest thing I have is a lower quality 25mm Ploessl: I would be loathe to
> use it though, as my FOV would shrink below 2 degrees! Another possibility is
> [snip]

OK I can take a hint.  Yes you would lose out.  I have dug out the
Java 2D API, but don't expect the new charts in a few days unlike the
talk slides.

> But is it infeasible for me to somehow use charts which cover a more limited
> area than my actual field of view? Or might I try stopping down the field of
> the 35mm further, to create an EXACT 3.2 degree FOV, for example? I hate to
> give you MORE unexpected work this month by asking for new charts, Malcolm,
> especially if we can manage somehow with the existing product!

You should allow some breathing room to allow for drift, unless you
have a tracking telescope.  Adjustments of the field can lead to
vibrations which might trick you into thinking you've seen a meteor.
That said, you could use the 3.2-degree field and only plot those
meteors which lie within or mostly within the bounds of the plot.
Because of off-axis perception variations only a small fraction would
lie in the outer annulus from 57 to 63 degree apparent.  Meteors seen
at the field periphery tend to have very short trails limited by the
field of view, so the speed and orientation aren't well determined.
So there isn't a great loss.  The thing to do is concentrate on the
inner region.  If you could put in a narrower field stop it would help
accuracy in the centre, yet lose few meteors.

To reiterate I don't have easy access to the CD drive on the Vax
system which I previously made all the charts.  Hence one need to
revamp the system to use online catalogues.  I'll see what `D' set
PostScript charts I have online, and others can be scanned.  You don't
need the whole set.  A subset around 40 or 50 would be suitable for
many of the known showers and for hunting for new/unknown ones.

Re. the Astroscan.  You want to avoid strain as much as possible.
You'll see fewer meteors and it's not good for your posture.

Hope that helps,

Malcolm

To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
References: