Two G-11 questions

[Omaroo]

Hey all :)

1) First light tonight with the G-11 brought out a question re; the Gemini. I use StarTarg and a webcam in the Megrez to set up my alignment. StarTarg asks that you temporarily turn off tracking so that you can see which axis of the reticule west is on. You then re-start the RA motor and continue on until it asks once more that you stp tracking.

How can you do this with a Gemini? Is there a setting you can go to quickly that stops tracking at sidereal rate for a moment without powering down? To power down means you have to go through the warm-start procedure all over again.

2) Does anyone use the Losmandy polar scope in Australia? I'm not sure that it would work here given that its FOV is around 12 degrees, and the engraved images of Achenar (a-Eri) and Crux are in reality nearly 60 degrees apart! How do you see even one of these markers through the polar scope and still see the pole? I take it that you can't use it here.... :(

Pic: first light :)

[[1ponders]]

Isn't there a terrestrial setting somewhere in the hand controller? If so you could use that.

Can't help with the polarscope question, I've only looked through one once and couldn't get it either.

[Alchemy]

yes you can use it here it has the required marks

Kenko Polar Finder Instructions
Rev. 2 - 14 Mar. 2005
Hutech Corporation and ScienceCenter.Net © 2000-2005
1
Kenko Polar Finder Instructions
This document describes the use of the Kenko polar finder as shipped with the Kenko Sky Memo R tracker. The
original alignment reticle produced in the 1990’s and early 2000’s included markings covering the period from 1990 to
2010. The updated reticle, which covers up to 2030, is described in Appendix A.
The Kenko polar finder is an illuminated reticle polar alignment tool which is designed for use in either the northern or
southern hemisphere. To use the polar finder in your mount, you must have a clear view of the polar region of the
sky. The first step in using the polar alignment scope is to roughly align the mount so that the pole area of the sky
Is visible in the alignment scope. This can be done by using known geographical references, or by using a compass
to set the azimuth and by setting the altitude adjustment appropriately for the latitude of the observing location.
Northern Hemisphere Alignment
In the northern hemisphere, the reticle marks indicated in
figure 1 are used. All other markings are for southern
hemisphere use. With Polaris approximately centered in
the scope, first rotate the scope reticle until Ursa Major
and Cassiopeia are in the same orientation as currently
seen in the sky. Note that these constellations are not
visible within the scope.
The second step is to use a combination of the mount
azimuth and altitude adjustments to place Polaris in the
gap indicated (A). Delta Ursa Minor is should be placed
in gap B. Fine adjustment of the reticle rotation may also
be necessary to get both stars simultaneously in place. If
your sky is dark enough, you will also be able to place a
third star in gap C for additional accuracy.
For maximum accuracy, place the stars as indicated
below in figure 2. The positions of Polaris for epochs
1990 and 2010 are referenced to the edges of the gap as
indicated below. The other two stars are referenced to the centers of separate tick marks as shown.
Kenko Polar Finder Instructions
Rev. 2 - 14 Mar. 2005
Hutech Corporation and ScienceCenter.Net © 2000-2005
2
Southern Hemisphere Alignment
In the southern hemisphere, the reticle marks indicated in
figure 3 are used. All other markings are for northern
hemisphere use. With southern polar area approximately
centered in the scope, first rotate the scope reticle until the
Southern Cross and Alpha Eridani are in the same
orientation as seen in the sky. Note that the Southern Cross
and Alpha Eridani are not visible within the scope.
The second step is to use a combination of the mount
azimuth and altitude adjustments to place σ Octans in the
gap indicated (A). χ Octans should be placed in gap B. Fine
adjustment of the reticle rotation may also be necessary to
get both stars simultaneously in place.
For maximum accuracy, the exact positions of the reference
stars must be adjusted for the epoch as shown below in
figure 4. The inner edges of the tangential tick marks are the
positions for the 1990 and 2010 epochs.
Kenko Polar Finder Instructions
Rev. 2 - 14 Mar. 2005
Hutech Corporation and ScienceCenter.Net © 2000-2005
3
Appendix A.
Updated Reticle for 2003-2030
Kenko Polar Finder Instructions
Rev. 2 - 14 Mar. 2005
Hutech Corporation and ScienceCenter.Net © 2000-2005
4
Northern Hemisphere
The updated northern hemisphere alignment points remain essentially as previously described, with the same three
stars used for alignment purposes. The text “N-03-10-20-30” is a reminder that the tick marks for the second and third
stars are for 2003, 2010, 2020, and 2030, respectively.
Kenko Polar Finder Instructions
Rev. 2 - 14 Mar. 2005
Hutech Corporation and ScienceCenter.Net © 2000-2005
5
Southern Hemisphere
The southern hemisphere reticle utilizes Sigma and Chi Octans as previously described, but adds two stars on the
opposite side of the pole for additional accuracy. These are SAO 258460 and SAO 258586. For Chi Octans, tick
marks are shown for 2003 and 2030 only since its position does not differ much over the period covered. The two
additional stars have tick marks for 2003, 2010, 2020, and 2030 as indicated in the diagram below. The text “S-30-
20-10-03” on the reticle is a reminder of the order of the positioning of the tick marks.

this is copied and pasted from a adobe pdf file, its too big to attatch here but a google search should find it AND PICCYS TOO for using it

i use mine and have NEVER done a drift alignment, my images are ok. the image of the southern cross is just a guide... its well outside the FOV.

hope this helps

cheers clive.

[Alchemy]

found a way to get the image to you

the stars required are marked sigma octans is clearly shown , if you can find that then the rest is easy. rotate southern cross to point to it. (roughly align) then fiddle til you get them lined up.

[Alchemy]

gees ive gotta read all the post..... the led is WAY too bright , i pinched a variable one from an astrometric eyepiece and attatched it in its place.... it needs to be dimmable.

[Omaroo]

Thanks heaps for this Clive - it's really appreciated. :thumbsup:

I can see how it works now. All that Crux and a-Eri are presented for is rotational orientation - you're not meant to overlay them with any markings as such. I didn't know about the Octans markers as they're not obvious like they are in, say, an EQ6 polar scope. Thanks once again.

[allan gould]

I have the ppolar alignment scope for the gemini/G11 and its the best scope of its sort that I have ever used. Its easy to roughly align using Crux and Eridanus. Then just place Sigma and Chi in the appropriate areas. Then after doing an alignment I usually do a PAC and if I'm really anal do a drift alignment from there. That is the way to really set up polar alignment.