Meade 12" LX90 - finding the celestial pole on a wedge

[Mark at Beaufort]

A group of us in Herefordshire have recently been granted sponsorship to build an observatory with a Meade 12" LX90 SCT. The Pulsar observatory will be erected this Thursday and the Meade will be installed on a Astro Engineering pier and heavy duty wedge with adjusters. I have no working knowledge of fork mounted telescopes on a wedge and clearly to do astro photography I need to find NCP not just Polaris. I have looked at various methods and the one that appeals is 'Kochad Clock'. However, there must be a number of you that have Meade/Celestron scopes on a wedge for astro photo work - any advice would be appreciated.

Once the observatory and scope are set up I will do a full report showing the construction, building and installation. The base is down and is complete with mains electricity and computer cables which are connected to a science lab in an adjacent High School.

The sponsorship from an international company and local benefactor requires that the observatory/scope is available to the community so interested astronomers in Herefordshire will have access.

Once again any opinions on setting up the Meade on a wedge would be appreciated.

Mark

[SteveL]

(Note, I have never used a Meade scope on a wedge, not have I actually used the item mentioned below)

AE do a wedge based NCP finder scope called the Polar Mate.... I know GreenWitch have at least one because I saw it this morning. It "hooks" onto the wedge like this:

And acts just like a polar scope

http://www.astro-engineering.com/LX%20SCT/accessoriesforme.html#polar

[rusirius]

I've been looking for something like this for a while. Trust it to turn up when I'm not looking!

Thanks for the link SteveL.

[barkis]

The Polarmate as shown by Steve is propably an excellent device for polar alignment, but an expensive tool if it is only going to be required for one off alignment, as will be the case for a permanently sited equatorial wedge in an observatory. That being so, then the star drift alignment procedure is a good way to do this job. Once the wedge has been levelled horizontally, and fairly well positioned along the local meridian, the star drift procedure is fairly straight forward.

If a night of good seeing is chosen, then it can be accomplished in a reasonable time.

Of course you will need an illuminated reticule, with parallel lined crosshairs.

The how to do it sequence has been posted in the help section of this forum. I posted one myself over a year ago, taken from the Astronomy magazine. Just be sure that the Azimuth adjuster, and the latitude adjuster on the mount work smoothly, and tightened after each incremental adjustment. The amount you need to move these, can be gauged during each preceding change, by the results you see in the reticule. You may of course know about this method, or one of your members will, in which case I'm sorry for prattling on. For an observatory sited mount, I think it is the best way to align. It is also a very good exercise in understanding the whole reason for the polar accuracy required for astro imaging. Even though a well aligned scope, may still require the auto guiding capability of the LX90 via the APM 900 Module plugged into a guide camera. Atmosphere and other anomalies will require small adjustments to be made that are not related to polar alignment.

Ron.

[Mark at Beaufort]

Thanks guys - been away first chance to reply.

I thought about the Polarmate shown by Steve but felt that once polar alignment had been set up the mount would not be moved so it was an expensive one off setup.

Very useful information Ron. It does appear to be the best arrangement and I am grateful for the suggestion on the auto guiding proposal.

Mark