Jupiter and synscan

[spektrumdx8]

Simple query,, Following lots of pages on here regarding the Skywatcher goto 127 synscan, bought one a few weeks ago and am generally pleased apart from it's accuracy in placing targets in the viewer- dialled in my co-ordinates according to google earth -

51.559678 N -0.374291 W - mount is facing true north and set up with the compass on my iphone, when it gets to Jupiter, its in the right direction but way out- takes a few presses to center in the finder scope- image also shows in main telescope,,,,,,

What am I doing wrong? Would the Synscan GPS Mouse help as I think this is where I'am going astray !

My handset is on version 3.08- would updating make a difference

[sunshine185]

Can you not use polaris to find north instead of your phone?

[cosmological]

If it's not precisely polar aligned than it won't find Jupiter. Pointing to what you think is north might not be good enough, and also your phone accuracy could be slightly out. Moving right or left to get it pointing north, don't forget up and down.

[Matt Scunthorpe]

Yes as stated above, you need to use Polaris. Celestial north pole and magnetic north pole are different things. It will also need to be aligned accurately for it to find objects near center of the EP

[spektrumdx8]

Thanks for all the advice guys,,

Here's hoping for clear skies tonight and will try and align with the pole star..

[Capricorn]

As previously said the initial alignment is one of the most likely culprits.

Even with a 25mm eyepiece you will only have a 1 degree view, slightly less. That view is edge to edge, we tend to talk about locating and centering as centre to edge, so 1/2 degree.

As Polaris is about 1 degree off the rotational axis even that will introduce an error that is twice the view. Is there not a centre on Polaris as the start position on the SW scopes now? May need a software update possibly.

I have found that it is difficult to actually estimate angles by better then about 5 degrees, so aligning with the iPhone will be a bit of a guess.

In effect spend more time and more care on the initial setup for level and alignment, it pays dividends. I found this the first time I used a Mak goto, couldn't get the first star in view and wasted the evening.

Is there not a method of obtaining better accuracy on these scopes, something like go to a nearby star (Aldebaran) pressing some button or other, to use that as the reference point, then going to Jupiter.

Also take into account that Jupiter is close to the ecliptic but not on it, it moves at a slightly different rate to the stars and at some time it appears to move backwards. Meaning that planets are not as simple as the stars are to determine their position. I am just thinking that when written the software may have used simplified assumptions on planetary motion.

A 32mm eyepiece will help, a 40mm has a fractionally bigger field of view so perhaps one of those. I bought a cheap 40mm, didn't care about the quality of the image just the width.

[tjr]

Is it alt-az or GEM? If it's the alt-az goto then aligning to north is not necessary.

[Cornelius Varley]

Your coordinates as noted are inaccurate. You need to convert them to degrees and minutes. 000 22 W 51 34N

[spektrumdx8]

Your coordinates as noted are inaccurate. You need to convert them to degrees and minutes. 000 22 W 51 34N

Will also try this as the manual is not exactly clear that the co-ordinates as listed from google earth have to be converted to work with the handset !!

Hence the reason I figured the gps mouse would be more accurate,,

Thanks again for all the advice