How Do I: Polar align when I can't see Polaris?

"Edward Smith" wrote in message
...
OK. The obvious answer here is I don't, at least with any accuracy.

I left the telescope inside tonight. There were high level clouds to
the north and I couldn't make out Polaris. I considered taking the
telescope out anyway but left it inside and am settling for
Binoculars. That brought up the question about how to polar align
when I couldn't make out Polaris.
Worth remembering, that Polaris, is only a 'starting point' anyway. It
allows you (with a good polar scope), to get within a few fractions of a
degree. Hence the process is iterative. Normally you start from the
'Polaris' reference, and then improve the accuracy by drift alignment. All
that not being able to see Polaris does, is potentially degrade the
'starting point'

I had some thoughts. First, I could get a good polar alignment and
simply make reference marks on both the ground where the tripod was
set (probably drive some tent stakes into the earth) and on the mount.
Then I could recreate at least a rough polar alignment in my most
common viewing location (read, back yard) anytime I wanted.

I could also do it by simply using a compass, correct for the magnetic
deviation at my location, and use my lattitude.
Yes. Either method will give you a starting point, that is nearly as good as
Polaris (may even be better...). One route for instance, is where there is a
fixed site, is to drift align, then mark the tripod leg positions, and then
if there are landmarks visible on the horizon, observe the
eyepiece/viewfinder view of the horizon, with a fixed RA/Dec reading. If you
reposition, and adjust to have the same view, the starting point will be
better than Polaris offers.
With a good compass/level, allowing for magnetic deviation, it is possible
to easily get a good starting point.

Because I am just starting to explore with the telescope and have been
having "finder scope alignment issues", I decided to pass on the
telescope until I could get a good polar alignment (which I can do
most nights, I should be out tomorrow).

Any other suggestions?
Everyone in the southern hemisphere, faces this all the time. There are
quite a few articles on the web about setup in these locations.

Best Wishes

Edward Smith wrote in
:


Use star drift in your eyepiece to correct alignment.
Do a rough polar alignment.
Use a star in the south sky at moderate elevation and center it in your
eyepiece, preferably with a crosshair, and with high magnification.

Now start following and see if the star drifts from the center.
Depending on what you use (say a zenithprism) the drift up or down
corresponds to an off setting to either the east or the west.

From the top of my head - with zenithprism: drift down more to the east
and drift up in your eyepiece move your mount more westward.
Please others here correct me if I'm wrong. And _if_ I am, you'll notice
soon enough and you have to reverse my instructions

After you have adapted the mount, center again and start all oveer
again. A few stints and you have a fine alignment.

I had read about this in the telescope manual, but wasn't sure how
valid it was.

From what I could gather, what you are doing is using the error in the
tracking to correct your polar alignment. The manual actually has all
of the directions (up, down, left, and right) and how to correct.
I'll have to play with the geometry until I understand it.

It is the most accurate way of aligning your mount if done carefully. You
don't need a lot of accuracy for visual observing though.

L.

Edward Smith wrote in
:


Use star drift in your eyepiece to correct alignment.
Do a rough polar alignment.
Use a star in the south sky at moderate elevation and center it in your
eyepiece, preferably with a crosshair, and with high magnification.

Now start following and see if the star drifts from the center.
Depending on what you use (say a zenithprism) the drift up or down
corresponds to an off setting to either the east or the west.

From the top of my head - with zenithprism: drift down more to the east
and drift up in your eyepiece move your mount more westward.
Please others here correct me if I'm wrong. And _if_ I am, you'll notice
soon enough and you have to reverse my instructions

After you have adapted the mount, center again and start all oveer
again. A few stints and you have a fine alignment.

I had read about this in the telescope manual, but wasn't sure how
valid it was.

From what I could gather, what you are doing is using the error in the
tracking to correct your polar alignment. The manual actually has all
of the directions (up, down, left, and right) and how to correct.
I'll have to play with the geometry until I understand it.

It is the most accurate way of aligning your mount if done carefully. You
don't need a lot of accuracy for visual observing though.

L.