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Polar aligning the NexStar SE telescopes

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#1 Silver Bear

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Posted 30 April 2013 - 05:41 PM

Perhaps I have missed this in the archives and stickies, but I'd like to know if A) these scopes can be easily polar aligned? and B) would it be worth the effort?

I can't find anything in the accompanying manual which even mentions this possibility. Is it hidden down in the utilities, under some obscure listing? :confused:

My thoughts on this is that I'd like to be able to just be able to hit the left/right arrows on the handset, rather than adjust both alt-az to manually slew to an object.

Thoughts?

Thanks in advance, as always!

#2 mclewis1

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Posted 30 April 2013 - 05:49 PM

Ted, If you put the scope on a wedge (or lean the 4SE over with it's built in wedge like setup) and then perform an EQ alignment then yes. Sitting vertically as is normal for alt az oriented scopes - no.

Polar alignment only applies to a scope/mount that's oriented "equatorially".

#3 Silver Bear

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Posted 30 April 2013 - 05:57 PM

In essence, wedge it up so that the arm is "pointing" at Polaris, then do an equatorial alignment?

#4 Arctic_Eddie

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Posted 30 April 2013 - 05:59 PM

Surprisingly, you can leave the scope in AZ/AL geometry, tell the controller it's EQ, and it will still align and track. However, it won't do you any good as the mount still has to use both drive axes to operate. Only a true EQ orientation will transorm the two axes into orthogonal DEC and RA.

#5 Tel

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Posted 01 May 2013 - 03:13 AM

Hi Ted,

A very warm welcome to CN and to this Nexstar forum ! :bow::bow:

To add my two penn'th: imagine that your 4SE were mounted equatorially and accurately aligned to the celestial pole so that every object you care to view will move in a clockwise arc across the skies. Thus, when you have alighted on the object you wish to view, you would indeed only have to move your 'scope to keep pace with its movement by pressing the right direction button on your hand controller.

However to initially reach, (slew to), whatever object you may choose, will definitely necessitate, as I'm sure you appreciate, the use of all four directional buttons. (Even if equatorially mounted and working under mount computer control, 'scope movement in both declination and right ascension would be required to reach any targeted object).

But I gather from your other postings that your main desire here is to "star hop" with your 4SE in which case you would still need to use the hand controller direction buttons to the full in order to do just that, whether your 4SE were alt./az. or equatorially mounted, plus the fact that, without having carried out an initial alignment procedure, you would still have to track your object manually after reaching it.

If therefore "star hopping" is your aim, there is however no reason why you cannot do this in so much as instead of calling up an object on your hand controller to which your 'scope will slew at the press of a button, just use the maximum slew rate available and use the directional buttons to slew to it, (star hop to it), yourself, rather than via the on board computer !

By this means, you will retain the satisfaction of having reached an object through your own "star hopping" skills and having reached it, the 'scope, having been aligned in the first place, will thereafter,track it for you !

Does this make sense in so much as what you are seeking to do ?

Best regards,
Tel

#6 cn register 5

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Posted 01 May 2013 - 03:40 AM

AFAIK the SE scope with the current 4.x or 5.x version HC can do the All Star Polar Alignment.

The scope must be on a wedge, then do a 2 star alignment as normal. Go to a star that's close to the meridian and not too high and use the Align - Polar Align - Align Mount option to do the polar alignment. Follow the instructions shown on the HC.

But I wouldn't bother unless you are trying imaging. Visual observing is fine with the scope in Alt Az mode and it's one less thing to do.

Chris

#7 Midnight Dan

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Posted 01 May 2013 - 06:05 AM

Hi Ted and welcome to the forum!

Your 4SE manual describes polar alignment on page 15. Look for the "EQ North / EQ South Alignment" section. If the manual you have doesn't have this section, you may want to download a new one from the Celestron website.

-Dan

#8 Silver Bear

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Posted 01 May 2013 - 11:46 AM

Thanks again - for warm welcomes and for the added information.

I obtained the updated version of the manual, and it is right there, on pp 15-16.

I realize I will still need all 4 directional arrows after polar alignment, but I'd like to minimize usage of the declination buttons where I can.

This is really more driven to find out what the telescope can/cannot do, and what makes for easier study of faint and not-so-faint objects.

Right now, I've started a double stars project, and was thinking that if I used a polar alignment, it might help me keep in mind which way north is when observing these stars...

#9 mclewis1

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Posted 01 May 2013 - 12:33 PM

In essence, wedge it up so that the arm is "pointing" at Polaris, then do an equatorial alignment?

Ted,

Yes, pretty much that's what's required.

Your mount has that little rod that allows you to tilt the base up so it points roughly at Polaris. You can also move tripod around to help with it roughly pointing at Polaris.

As Chris mentioned for visual work that's probably all you'll need to do. Doing a formal polar alignment (using the built in firmware routine) is generally considered overkill and unnecessary for visual work. You'll probably be surprised at the goto accuracy you get from the normal EQ alignment after doing just a rough "by eye" polar alignment.






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