Hi Alan,

Aha! OK, now I see what you're driving at.

The problem is one of determining some alt/az points
surrounding that big 30-degree diameter disk centered on
Polaris. Knowing your MPC code gave me your latitude;
I reset to that, then centered Guide on assorted points
at declination +60, at 1h30m intervals in RA. That gives
sixteen points; in reality, I looked at eight, noting the
alt/az for each. Then I mirror-imaged them to get the
remaining eight. So you now have a sixteen-point polygon,
not eighteen, and the values are

f 16 48 0 0 ; altitude cap
4.8 22.0
16.7 24.7
27.8 30.0
37.8 37.5
46.2 46.8
52.3 57.4
53.5 68.6
37.3 78.9
-37.3 78.9
-53.5 68.6
-52.3 57.4
-46.2 46.8
-37.8 37.5
-27.8 30.0
-16.7 24.7
-4.8 22.0

Looking at it another way, if a person at your latitude looked at
altitude 22.0 degrees, azimuth 4.8 (or -4.8) degrees, she would
be looking at a point at declination +60.

Conventionally speaking, azimuths such as -4.8 should be
replaced by 355.2. But I was lazy, and Guide is perfectly happy
to read in such azimuths in the object list.

Now, in theory, a person at your latitude of +51.8 ought to be
able to simply use this:

c 48 0 0
0 51.8 30

...that is, "Draw a circle in a shade of red, centered at azimuth=0,
altitude=51.8, radius=30." But I see Guide doesn't account for the
distortion large circles experience when projected. Something I
may be able to puzzle out...

-- Bill