Tracking with AZ goto mount

[Darren27]

Last night I was trying to get a view of Jupiter between the clouds with my small refractor, but was having problems keeping centered as the cloud passed. I was wishing I had a powered EQ mount which would track accurately so I could maximise the time spent observing when the cloud allowed.

I am considering a AZ goto mounted scope and I was wondering how they would cope tracking in conditions like last night. It would have been very difficult to get a full two or three star alignment, but could you just manually locate a target, like Jupiter and then simply get the mount to track it in the same way as an EQ mount with an RA motor drive?

Sent from my LT26i using Tapatalk

[jgs001]

a two or three star alignment is used to help the mount electronics understand the sky so goto's are more accurate. You don't need to do this unless you're planning on hopping around all over the sky. If your objective is something like Jupiter, then you can either perform a solar system alignment on Jupiter itself, or use a nearby star for a one star alignment and then goto to the target. Personally, I'd just use a solar system alignment. Once complete, you're tracking should be good for quite some time. I don't recall personally, but from memory, something like 30 to 45 minutes without issue.

[ronin]

I am not sure that an alt/az goto mount can track if you manually locate a target. The position of the object must determine how that target appeards to move.

Try this:

Target is close to Polaris say Mizer+Alcor.

The sky rotates apparently counter clockwise.

(1) M+A is directly below Polaris the movement appear to be only horizontal and to the right.

(2) M+A is to the right of Polaris the movement appears to be only vertical and upwards.

(3) M+A is directly above Polaris the movement appears to be only horizontal and to the left.

(4) M+A is to the left of Polaris the movement appears to be only vertical and downwards.

You can see that unless the mount is aligned and knows where it is pointed, read from the goto target data and time, then it cannot apply the correct up/down/left/right drive to the scope to keep the object in view.

I know that on a Meade there is basically the option to just use the default start position, Level and North. You do not need any alignment stars for this, the software has to assume that the scope is perfectly level and pointed perfectly North. You can then tell the scope to goto Jupiter and using the supposidly perfect start it will go and point to where Jupiter should be. Then using the Jupiter data and time it has it will apply the appropriate tracking. This could well be good enough for visual. The "ease" of doing this depends on the FoV of the scope.

I have no idea if similar exists on other Alt/Az mounts. It is useful for solar viewing as try as I might I cannot see alignment stars during the day. :Envy:

[Killie]

I know my Skywatcher Az/Alt Goto will track reasonably okay provided I start level and pointed true north. I did it once on a very variable day and whilst it wasn't perfect (Because I didn't get north right) it did enough of a job so I didn't need to tweak it much.