A few questions on polar alignment?

[Aleforge]

I bought a new house that I can actually see Polaris from! *cheer*

Anyhow, I calibrated my polar scope on a far away object and adjusted it for an hour to finally get it very close. I looked up my latitude on Google, and came up with 38. I positioned the adjustment to about 38, went out and leveled my mount, pointed it due north and looked through the polar scope. Polaris was MUCH higher than my 38 degree setting! Anyone know why that is? I had to adjust it up another 15-20 degrees to get it in the sites?

With Polaris centered by eye I soon learned I could not see the cross hairs to center it perfectly? How do you guys make sure Polaris is dead center in the cross hairs?

And a bonus question, once this is all centered up can I point the scope anywhere lock it down and run the motor to track, or do I need to stick to only moving one axis? I am thinking it doesn't matter what contortion you position but wanted to make sure?

Thank you so much!

[RT65CB-SWL]

Hi 'Aleforge' and welcome to SGL.

Just a quick answer to your question. What mount are you using? Polaris is not quite zero degrees.

[jambouk]

If you live at 38 degrees north, polaris will be at 38 degrees above the northern horizon. The calibration/marker strip must be wrong. If you take a step back and look at the mount side on, the RA axis should now be at 38 degrees roughly to the ground.

Are you sure you were aiming at polaris?

Once you have pilar aligned, you can move both the RA and declination axes without upsetting your polar alignment, as you are aligning the body of the mount to the north-south axes, and that doesn't change as you move the scope around.

[PeterCPC]

Check with Stellarium or Google night sky to help you locate Polaris. It's at the end of Ursa Minor.

Peter

[Astrosurf]

For visual, centring Polaris on the cross hairs is fine. But if you want better tracking, let us know what mount you have and we can better advise.

Alexxx

[jambouk]

This useful picture hopefully demonstrates how you can move the scope in both the RA and declination axes, but the mount stays polar aligned:

I can't reference the source currently as my browser on my phone has frozen.

James

[jambouk]

From: http://www.astronomysource.com/category/telescopes-and-more/

[Digger1895]

I take it the scope is levelled?

[chiltonstar]

I take it the scope is levelled?

Shouldn't matter, providing the polar axis is correctly aligned (well, unless the mount is tipped so much it's in danger of tipping).

Most of us align our scopes correctly, then mark where the feet go on the driveway/patio with white paint marks, so that it can be put back quickly in position and be aligned reasonably accurately, at least for visual observing.

Chris

[stepping beyond]

I've been working on my polar alignment and it is getting easier for a precise alignment . now since I've never used a polar scope or a goto mount. It is proving to be fun when everything is done correctly level the tripod before you put the ota on, balance the scope, check you tripod level again. Align Polaris and kochab on the weightbar {kochab towards the bottom}  look in the polar scope adjust altitude with altitude adjustment knob if need be. The web is good place to get your coordinates, I have a little circle to get Polaris close to because your not centering on Polaris your aligning to the NCP which is 2 finger widths away . Once you get the procedure down , it doesn't take as long to do it. You've gotta make sure your alignment is good or everything will drift and if I get a drift I go back and do it again until it's spot on , I need a precise alignment for imaging.

[Billy Bluelight]

I bought a new house that I can actually see Polaris from! *cheer*

Anyhow, I calibrated my polar scope on a far away object and adjusted it for an hour to finally get it very close. I looked up my latitude on Google, and came up with 38. I positioned the adjustment to about 38, went out and leveled my mount, pointed it due north and looked through the polar scope. Polaris was MUCH higher than my 38 degree setting! Anyone know why that is? I had to adjust it up another 15-20 degrees to get it in the sites?

With Polaris centered by eye I soon learned I could not see the cross hairs to center it perfectly? How do you guys make sure Polaris is dead center in the cross hairs?

And a bonus question, once this is all centered up can I point the scope anywhere lock it down and run the motor to track, or do I need to stick to only moving one axis? I am thinking it doesn't matter what contortion you position but wanted to make sure?

Thank you so much!

Well, I'm pretty much a beginner, but a few tips I've learned and which may help you:  

1. Ensure your finderscope and telescope through the eyepiece are correctly in tandem in daylight - it makes life so much easier at night.  Focus on a distant building, church tower, whatever, and get these as accurately aligned as possible.  After that be careful not to knock the finderscope.
2. I find a red dot finder (inexpensive) very useful at night to point me roughly where I need to be to align - much easier than the finderscope.  If all three are aligned together it's very simple - point at Polaris with the red dot, check that it's in the finderscope or near to, (adjust as below), then check it's in the eyepiece and that's it. 
3. That done, firstly - before doing anything else - make certain if you have any "Home" position marks on the two axis that the scope is set to these - in other words, make sure the tube itself is going to be pointing at or near Polaris when you point the tripod north.  I have wasted some time aligning on Polaris only to find I am nowhere near anything I try to point at.  As a general rule, the bar the weight attaches to must point to north, with the scope in the same alignment above it.
4. Make sure you use a spirit level to get the tripod roughly level.  Depending on what you are going to do, it doesn't have to be perfect - for example observing rough is enough I find.
5. As Jambouk said - you must be sure you are aligning on Polaris otherwise you have no chance at all.  Look north for the Great Bear/Ursa Major - or the Big Dipper in the Great Satan I believe .  I find it best described as a saucepan or cream ladle.  
6. Look for the two stars that form the outside edge of the four that make the pan or ladle (opposite to the handle of course) draw an imaginary line through those two stars and that will point you fairly close to Polaris.  Polaris is the extreme edge of the handle of the Little Bear/Ursa Minor - presumably the Little Dipper in the Great Satan - a very similar shaped constellation but much smaller.  It's easily recognisable as Polaris is about the brightest star anywhere near and is the first one visible in that direction at sunset.
7. Then - ignoring the scale as it will be pretty useless - adjust the latitude up or down using the screw mechanism and the telescope left or right BY PHYSICALLY MOVING THE ENTIRE TRIPOD - NOT USING THE ADJUSTER SCREWS! (that will move the tube from the "Home" position) - until you have Polaris visible in your red dot finder or your finderscope.  If accurately calibrated together, Polaris will now be visible in the eyepiece.
8. Remember Polaris is not actually at North - it's pretty close to but but not precisely, so don't spend ages getting it spot on - it will be wrong if you do and it needs to be "off" in any case.  The only thing is, we don't know which way it's "off"!.  If you had a polar scope it will apparently help to get it precisely aligned.  I have a Goto scope with an alignment set-up procedure - not sure what your system is.
9. As Chilton Star said, once you get it right then mark where the tripod points touch the ground with paint.  If you don't want to make it that obvious on a nice patio then mark circles around the feet  with a black or navy blue marker pen.  That way (assuming your isn't white) it will still show up under torch light but not much in daylight.  That done, from then on all you do is place the tripod feet on those marks and Polaris will be in the eyepiece every time.

No doubt there are better more accurate ways the experts will know, but that all works for me.  Hope it's of some use.  

[ollypenrice]

St Peters is at 38 47 N which is nearer 39 than 38 but if your mount was levelled then I can't see it being that far out. I suspect you weren't looking at Polaris. This is the classic method using the two 'pointer stars' in the Big Dipper;

http://www.google.fr/imgres?imgurl=https%3A%2F%2Fmandalashaman.files.wordpress.com%2F2011%2F12%2Fursas2.jpg&imgrefurl=https%3A%2F%2Fmandalashaman.wordpress.com%2Ftag%2Fpolaris-and-2012%2F&h=406&w=576&tbnid=chhODc64L7PcHM%3A&zoom=1&docid=e95zTakB9IJUEM&ei=XRpmVPvSIoPfPbzkgNAH&tbm=isch&iact=rc&uact=3&dur=1190&page=1&start=0&ndsp=27&ved=0CDEQrQMwBQ

In truth levelling is not necessary and can be miles out while still being perfectly aligned. On expensive Takahashi mounts there is no mechanism for levelling. What levelling does on other mounts is simply set your polarscope recticle correctly but this is not something to fuss over.

Olly