[AZ-Observing] Re: best seeing sites and times

  • From: "Frank Kraljic" <FJKraljic@xxxxxxx>
  • To: <az-observing@xxxxxxxxxxxxx>
  • Date: Sun, 14 Mar 2004 21:53:36 -0700

The problem with my balcony setup is vibrations.  Even if I stand very
still, I can note the vibrations of my heart beating (!) at high
magnifications, like 560x.  I have another, smaller, balcony outside my
bedroom, which is much more stable, but looks to the southwest.  It was
great for the last couple Mars oppositions, but the zenith is obstructed and
as a result, I have a small window to observe Jupiter and Saturn.

Interesting how you rated the seeing based on the scope you view through.
For many years I've struggled with, I guess, the subjectivity of seeing
scales used by amateurs; as the scaling relates to the aperture of their
scope.  An observer like yourself on one night using a 5-inch reflector may
rate the evening as a 7 based on the Pickering method, but through my
10-inch, I would rate the evening as a 4 or 5.  Personally, the one constant
I know that translates to all scopes and observers is magnification: What is
the highest magnification the seeing will allow to maintain a sharp view?
So for example, if I can consistently observe say, Saturn, sharply at 560x
through the 10-inch, then another observer, regardless of his scope's
aperture has a good idea of what his scope can achieve, as well as the
night's seeing.

I'm curious what people's thoughts are on this methodology.  Using
magnification is more universal than determining seeing based on the
diffraction patterns of stars, except for the purposes of maybe one's
telescope and personal observing logs.


  Using your scale, my average seeing looks like a 2 in my
> 10" and a 3 in my 5".  Occasionally I get nights with 4 seeing in
> the 5" but
> only a 3 in the 10".  I like the idea of your balcony setup.  Getting up
> above the ground level probably does help quite a bit.

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