Telescope tracking issue

andrea tasselli:
If that is a 10s unguided image than, at your image scale, this shouldn't happen (unless your PE is of the order of 1') IF you have carefully polar aligned the mount, which I suspect isn't the case. The lx85 does support a polar scope but I assume yours hasn't got one, isn't it right? So you need to learn to do it without one before you take any image. If you need guidance let me know and I'll post a guide on how to do it without anything other than either a camera (and computer) or a high-power eyepiece.

will autoguider solve my bad tracking problem? what about the probability of a problem with the gears?

andrea tasselli:
How to polar-align (in the Northern Hemisphere) a Newtonian telescope without a polar scope or any other overpriced gizmos.

1. First make sure that the finder is aligned with the optical axis of the scope which can either be achieved by pointing the scope to a far away feature (several km away) or using the Polaris itself. If you don't have a finder scope then ignore this.

2. Eyeball the position of Polaris as well as you might by either peering through the bore for the polar scope or using any suitable reference on the mount itself and move the mount so that you get it your sight by just displacing the mount.

3. Make sure that the counterweight bar is pointing as down (toward the ground) as possible. Mount the telescope on the mount and adjust the DEC axis so that is directed toward Polaris. Make sure that the azimuth adjustment screws are evenly positioned (so neither to the left or the right of the center position).

4. Peer into a low power eyepiece and see if you can see Polaris. If not adjust the altitude screw so you have it within the EP FOV. If you have a finder scope than the whole procedure can be more easily performed using that instead of the scope itself.

These first 4 steps are to make you are coarsely aligned with the NP as well as to make sure you have enough latitude of adjustment in the azimuth controls for the real job of PA the mount.

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Now to the actual procedure itself:

5. Move the telescope manually so that point at a bright star near the meridian within 10 degrees of the celestial equator. Make sure the mount isn't tracking. Mount the camera (let's assume a DSLR) so that the long axis of the camera is either at 90 degrees to the optical axis of the scope or parallel to it. Or just place a mid-power EP in the EP holder

6. Establish which side is North and which is south by nudging the scope up and down, either in the EP (easier) or by looking at the live view screen in the DSLR or by hooking the camera to a a PC with APT installed or any other software capable to display the live view from the camera. 

7. Once established which way is North (or South) you can turn on the tracking and see which way the star goes. It can either be toward North or South. If it is toward the North then shift the mount using the azimuth controls toward the East, vice versa if it drifts towards to South. Once there is no significant movement either way go to the next step.

8. Now shift the mount so it points to a star 6 hours before crossing the meridian (i.e, East). If the star drift toward the North then you need to lower the polar axis (of the mount, using the altitude screw) and the opposite if it veers toward the South. You can do the same thing if instead of the East you point West (6 hours after crossing the meridian) just invert the terms North with South in the adjustments above.

9. Go back to the meridian and repeat step 7 until there is no discernible drift either South or North (East to West is irrelevant here) for around 1 min and you have nailed your PA.